History ThatOneBoss / RPG

-> "It would be [[MookChivalry unfair]] to make you fight all four Advisors at once, but...fair treatment was never shown to my people. I'm just returning the favor."
--> --'''Kael'thas Sunstrider,''' WorldOfWarcraft

*** ''Also'' from ''Bloodlines'', Wereshark. Deals massive aggravated damage with every punch even with high-level fortitude, can take a serious beating... oh, and you have to kill him without him killing Yukie. Odds are if you try and deal with him with a gun he'll maul her... and you'll hit her too. Good luck if you're a clan without Celerity. Damn near impossible as a Ventrue (Presence doesn't affect him, but does hinder Yukie, and Fortitude might as well not be on).

** This Troper got all the way to Maleficent using the starting deck. Even after editing the Deck, he still never Card Broke anything intentionally. By the time he got to Riku Replica (Fourth time), it took this troper a year of ocasional play to defeat him, it doesn't help that right before him you have to mash through a very long cutscene. By the end of the battle, this troper had mastered the game and had a deck that tore through the last four bosses like a hot knife through butter. All from one battle!

*** This troper's plain-vanilla single player Assassin character had an excruciating time with the Ancients on Nightmare difficulty. It eventually took a new weapon (made with rare runes), an entire belt, inventory, and Horadric Cube stuffed with Full Rejuvenation potions, and about twenty minutes of nonstop running-like-hell-while-flinging-blades to take them down. My mercenary was dead in about five seconds. I had to repeat this several times before finally succeeding. Needless to say, my character is not going to make it to Act V in Hell difficulty.

* Red Testament from ''{{Xenosaga}} 3'' is a rather interesting example. Most fights in the game are strategic, and level grinding is avoidable, but this guy blows every boss before him out of the water, as well as the FinalBoss. Being preceded by a [[{{Crunchtastic}} spoilerific]] TrickBoss fight beforehand, and the game's CrowningMomentOfHeartwarming doesn't temper this, but it may lead the player to a false sense of security. By this time, every character can have Safety and Best Ally available for use, which automatically revive a character it is cast on after they die. This is important, as Red will beat the tar out of every squishy character with incredible speed, and with Break every tough character with that same speed. Victory comes from poking the enemy to death over the course of the entire fight. That said, [[{{Laurarola}} This Troper]] still managed to finish him off in one attempt, so it is possible to walk into the fight semi-prepared and win, a rare thing for a ThatOneBoss in an RPG.

* The final boss of ''Arc the Lad II''. At the beginning of the game, the level progression of your characters keeps pretty even with you enemies. However, in the last couple dungeons, the enemy difficulty skyrockets upward at a rate greater than natural character progression. If the player either hasn't spend absurd amounts of time grinding in the game or in first game (to unlock a certain move in the sequel), the final boss will be absurdly, crazy hard. It took this troper about three-and-a-half hours of real time to beat the boss.

* ''MarioAndLuigiSuperstarSaga'' has the Piranha Mom, who is not only tough herself, but spawns two smaller piranhas. Which wouldn't be so bad, except the only way to win the battle is to attack Mom directly, whereupon the two smaller plants both spit fire/lightning at both Mario and Luigi. Did I mention that there's no real way to predict which brother is going to be attacked by which plant, unlike ''every other enemy in the game up to that point'', and the attacks seem to vary timing to make them hard to dodge? Did I mention that Mom regenerates health, and creates new Piranhas any time the old ones die? This troper figured he was screwed when every FAQ he consulted said "better stock up on healing items!"

* ''EverQuest 2'''s Raid Battle against Venril Sathir qualifies for this in spades. Not only do you need 2 copies of the same item from a previous raid mob to even make him DOABLE (thankfully they aren't consumed by the battle), the fight is simply unforgiving of ANY mistake. Guy on statue duty lags? Everyone dies. Someone doesn't cure their poison? Everyone dies. Someone casts too much/not enough? Everyone dies. Venril Sathir decides to screw you by giving the same person both his curses at once? Everyone dies. Someone crosses the threshold of his room too soon? Everyone dies. Venril is the raid mob in ''EQ2'' responsible for more raid guilds breaking in half than any other. The kicker: He's not even an end of progression boss, he's in the middle of an expansion's progression. As this troper's guild put it: "Venril is the mob you fight when you want to make a guild that eats Avatars (the endgame raid content) for lunch feel like a bunch of level 10 idiots."

* ''TacticsOgre'' has quite a few difficulty spikes. If one takes the right path (This troper forgets which one), you have to fight both Oz ''and'' Ozma at the same time (Along with the rest of their units). Now during the other two paths, you only fight ''one'', and when they are defeated, the battle ends. It's much easier with just Oz because they are both rather difficult and he starts off rather close to your units. (Having a one-on-one match with Denim before they call their armies out) Let's also not forget the battle with Lans Tartare...considering he's the ''commander'' of the Dark Knights, highly justified.

* ActionRPG MetalWalker has one in the form of B. Dragon. He does a fair amount of damage even if you grinded...and his amount of HP is MASSIVE. Even if you do 77 damage with each hit, he will likely kill you before you kill him, especially if he or his minions get good capsules. This troper beat him by stalling until HP 2 Capsules came into the arena.

** I only managed to defeat Dragon Maleficent by waiting my party members to reduce her HP, while Sora stand from the distance avoiding her ranged attack (Thank goodness, she cannot run after Sora). When she (It can be a while with your party members getting KO'd constantly) finally have low enough HP for Sora to go ahead and defeat her, before she knock him out first.
** This Troper personally finds the Riku fight the hardest in the game, it took her ''weeks'' to defeat him, and the fight with Maleficent directly after? Beaten on the first try.
** This Troper actually finds Giant Ursula to be absurdly hard. Dragon Maleficent was ''cake'' next to that, and Riku only slightly tougher than the dragon.
*** I agree, try her on hard/proud mode and tell me she is easy. The little thing that shoots beams from above does half your health, her bite does 3/4, the bubbles for 1/4 each, then she gets her beam spam ability and the fight ends up lasting forever and one screw up, you die, start over.
*** Are you serious? Ursula is the easiest boss to me. She only targets sora and if you use Ariel and donald you almost never need to heal anyone. you dont even have to attack her. just swim all the way towards the camera and as far up as you can. only the sky lasers and maybe bubbles will hit you. all you really gotta do is heal when necessary (which donald and arial do anyways so maybe not) and attack her to speed up the battle since ariel and donald will be hitting her the entire time.
** I had my own crazy experience with the second show-down with Riku. When I first played the game, I just could ''not'' beat Riku, so much I stopped playing. When I started playing agin three years later (with a new save file) it took me forever to beat Ursula as well as the second Maleficent. But when I faced Riku the second time, I beat him within 2 minutes.
** The first time I played Kingdom Hearts, while I had a lot of trouble from all of the above mentioned bosses, The worst for me was Chernabog. I literally could not beat him the first time i went up against him, to the point that I stopped playing for nearly a year. Even after I went level grinding for a few hours, it was still tough. Then, the second time I went through the game, I went for a completely different strategy and had no problems at all. It made me wonder why Chernabog was That One Boss for me the first time.

* Most of the bosses in ''LastScenario'' can be this thanks to NintendoHard BossDissonance, and because of this no one can seem to agree on which is the worst. The [[WakeupCallBoss first one]] that's likely to make you bang your head against a wall is the Marid King, but later ones (particularly the NighInvulnerable Riftgate, the Vivionnes, a mob of 5 [[GiantSpaceFleaFromNowhere inexplicable critters]] that constantly heal and revive each other, and any boss that spams {{Total Party Kill}}s and [[TheComputerIsACheatingBastard status effects]]) can be even worse. And that's even without hitting the {{Bonus Dungeon}}s or ThatOneSidequest and finding yourself facing a BonusBoss with [[MarathonBoss 200,000 HP]] and an attack that can deal 10,000 damage per hit.

** Actually, Bundt straddles a line between 'really easy' and 'ridiculously impossible', with almost no space in between, depending on your characters' level. Unlike all other bosses, Bundt has no HP - you have to knock out all of its 5 candles. One attack from you knocks out one candle, one attack from Bundt restores one candle. You have three characters, the cake has two parts and thus regenerates two candles per turn. If you can manage having everyone in your party attack each round, the fight will be over in 4 rounds (well, the first part of the fight, but after that the more conventional second part is a pushover). Of course, that means you have to be able to swallow 4 consecutive rounds of pretty hefty magic without healing once, so...

* [[MassEffect Mass Effect 2]] has Praetorian, an exceedingly frustrating boss. First, it's a flying tank that can fire a powerful laser beam at you, and often only you, with perfect accuracy. It has a shield that is difficult to bring down before you can even begin to deal damage to it. Once you take that shield down, it will wait a few seconds and then slam itself into the ground, setting off a shockwave that stuns anyone nearby. Once the stun wears off, you have only a second to get away before the boss sets off an energy pulse that is almost always a one-hit-kill to anyone within a few yards. Then it will rise back into the air with its shield fully recharged. The final kicker? It will always slowly float towards you, so while you're hiding under cover to keep away from its laser beam, it's getting closer and closer to getting you with the insta-kill energy pulse. For a game that is mostly tough but fair, such that if you die you'll know what you did wrong and how to do better next time, Praetorian suddenly crosses the line between challenging and NintendoHard.

* Ser Cauthrien from [[DragonAge Dragon Age]]. Maker's breath, Ser Cauthrien.
** Considering that you're usually around lvl18 by then -and the mobs scale with you, skills included-, and she's escorted by no less than six archers -each of them capable of spamming Scattershot-, not even an insanely geared [[GameBreaker Arcane Warrior]] with every [[DeflectorShields aura and sustained effect available]] up and running will be able to stand up to her and her cronies for long.

* ''BreathOfFire 2'' certainly had a fun one in the form of Barubary. He's statistically the strongest enemy in the game (this includes the final boss, by the way, never mind that said final boss is freaking '''[[spoiler:[[DidYouJustPunchOutCthulhu G]][[GodIsEvil O]][[UltimateEvil D]]'''). And to get the [[InfinityPlusOneSword Infinity Plus One Armor]], you have to face him ''alone''. With no reduction in his stats.

* Ser Cauthrien from [[DragonAge Dragon Age]]. Maker's breath, Ser Cauthrien.
** Considering that you're usually around lvl18 by then -and the mobs scale with you, skills included-, and she's escorted by no less than six archers -each of them capable of spamming Scattershot-, not even an insanely geared [[GameBreaker Arcane Warrior]] with every [[DeflectorShields aura and sustained effect available]] up and running will be able to stand up to her and her cronies for long.

* ''{{Xenogears}}'' has several of that one boss throughout the game which makes it frustrating at times. The first one that comes to mind is the second fight against the FiveManBand that fights for Solaris. What makes it hard is the fact that you first face two of them at one time. Then you have to face three of them next at one time and you don't get a change to heal before it. Then you have to face [[spoiler:Elly]] with all of the damage received from the previous battles. Redrum is another pain to fight. Not only does he have a move that will damage your party and heal himself at the same time, he also has a move that kills one character and heals himself at the same time.
* This editor doesn't expect that anyone else besides herself has heard of ''LilMonster'', an obscure Game Boy Color RPG, but would nontheless like to nominate the infinitely infuriating Kromar for ThatOneBoss status. He's got a metric buttload of HP, ridiculously high strength that makes even his weakest attacks do almost 100 damage, and copious healing gems. However, he ''also'' makes liberal use of Meteor Drop, the most powerful attack move in the game--which does something like 230 damage per hit, coming from him. If you've been LevelGrinding up to that point of the game, you're likely to have about 400 HP, give or take. Yeah. He's ''hard.''

* The Steel Mechorilla from ''{{Mother 3}}''. Nothing gimmick-y about him-- he's just very, VERY powerful, powerful enough to beat up all your characters without the slightest difficulty. And he has a ton of HP. ''And'' he powers himself up if you [[spoiler:cast PSI Thunder more than twice]], becoming even tougher. This troper (after getting his rear handed to him the first time) came back with all four characters' inventories loaded with healing items... and ended up using ''almost every single one.''

* ''LegendOfMana'' tries to avoid making baddies too difficult; either placing new lands close to home, or [[GameBreaker learning blacksmithing]] will let you through nearly everything. If you don't, though, it can get very ugly. Irwin essentially spams an area of effect power that fills the entire screen. The dragons hit a bit too hard to be fair. But the worst is the Sierra and Vadise fight. Large area of effect powers, some of which cause the player to fall asleep, nasty amounts of health, and you can only bring one ally where you'd normally get two. Even better, they [[IGotBetter get back up]] if you don't beat them both at the same time

* In ''TheWitcher'' [[spoiler:In the proper fight at the end of chapter 5]] Azar Javed qualifys. He will regularly blind or knock you down, both will disable you for a significant period of time, only one of the two can be properly defended against (willow potions prevent knockdown), blind can only have it's effectiveness decreased by spending a talent on an ability that stops it from working sometimes (and no other enemy in the game seems to use blind and silver level talents aren't something you throw away...). To make matters worse, if you made certain choices in the game, this battle has an escort who will die if you lose the bosses attention and he starts to attack them ([[spoiler:Berengar]] is really OverratedAndUnderleveled) and you have to start over if you want to save him (admitedly, this doesn't get you anything). Also, one of the early bosses in the game, The Beast, is ''[[ExactlyWhatItSaysOnTheTin well named]]''.

* Being NintendoHard, ''OdinSphere'' (which is not [[ThatOneBoss/{{Atlus}} MADE by Atlus]], but is published by them!) has most of its bosses falling into this category, but Velvet vs. Beldor and Belial is the one that really makes this troper cry. To say it's a warping, spellcasting wizard (and even mook wizards are a bitch and a half to fight) and a ginormous rampaging dragon teaming up to fight the character with the lowest attack power in the game is to make a gross understatement of the exact levels of evil the player faces in this fight. And then after it's over, Velvet [[spoiler: ends up captured by the bad guys anyway, to be rescued by [[BigDamnHeroes Cornelius]] later]]. So that's awesome.

* ''TacticsOgre'' and its GaidenGame ''KnightOfLodis'' have quite a bit of difficulty spikes. If one takes the right path (This troper forgets which one), you have to fight both Oz ''and'' Ozma at the same time (Along with the rest of their units). Now during the other two paths, you only fight ''one'', and when they are defeated, the battle ends. It's much easier with just Oz because they are both rather difficult and he starts off rather close to your units. (Having a one-on-one match with Denim before they call their armies out) Let's also not forget the battle with Lans Tartare...considering he's the ''commander'' of the Dark Knights, highly justified.

* The final battle against Magic Emperor Ghaleon in ''{{Lunar}}: Silver Star Story Complete''. He is incredibly fast, attacks twice per turn, and has an ''incredibly'' powerful arsenal of doomsday spells that can devastate your entire party in two turns flat, not to mention a 1000-HP shield, an HP-draining attack, and an instant death spell. This troper has never had to attempt a final boss battle - or indeed, any boss battle at all - so many times before, and never has since. My friends and I are actually convinced that it is impossible to beat him on one's first try, because he only seems to (slightly) relent in his maelstrom of doomsday spells when you attempt him the second time and beyond -- to this day, we know of no one who defeated him on their first try.

* [[MassEffect Mass Effect 2]] has three exceedingly frustrating bosses: Praetorian, Praetorian and [[OverlyLongGag Praetorian]]. First, it's a flying tank that can fire a powerful laser beam at you, and often only you, with perfect accuracy. It has a shield that is difficult to bring down before you can even begin to deal damage to it. Once you take that shield down, it will wait a few seconds and then slam itself into the ground, setting off a shockwave that stuns anyone nearby. Once the stun wears off, you have only a second to get away before the boss sets off an energy pulse that is almost always a one-hit-kill to anyone within a few yards. Then it will rise back into the air with its shield fully recharged. The final kicker? It will always slowly float towards you, so while you're hiding under cover to keep away from its laser beam, it's getting closer and closer to getting you with the insta-kill energy pulse. For a game that is mostly tough but fair, such that if you die you'll know what you did wrong and how to do better next time, Praetorian suddenly crosses the line between challenging and NintendoHard.
* ''Labyrinth of Touhou'':

** Many people found themselves stuck on the boss right before the Heart-to-Heart scene, [[spoiler:Guillo]]. It has ''ridiculously'' strong stats, and is easily the most powerful enemy you'll face in the game (possibly even more than the final boss!). It can wipe out half of anyone's HP with a couple of normal physical attacks, and then KO them completely with a devastating finisher. It also has a finisher that will randomly hit the entire party, meaning one of two things: everyone will be brought down into the red zone, or you'll be left with one or two devastated characters. The worst part about the fight is, after beating it, it turns out to be (like practically every other boss up to this point) a HeadsIWinTailsYouLose situation; story-wise, the boss just knocks everyone out anyway, making you wonder why the developers didn't just go for the HopelessBossFight solution.

* The Tarantula in ''{{Lufia}} II'' is a pretty big kick in the nuts to first-time plays, boasting high HP (relative to your damage output), the ability to summon smaller annoying enemies to aide him, an attack that knocks off a lot of damage from all your party members while having a good chance of poisoning each member, and a normal attack that also happens to have a chance of causing full paralysis to the target. Did I mention he has a ton of HP? If you managed to defeat him the first time through, you either power leveled or got extremely lucky.

* Lenus from ''LegendOfDragoon''. Casts ridiculously powerful spells that hit everyone, uses a physical attack... that hits every one, and is so fast she'll likely get three or four turns in a row before your party gets to act. Better hope you've done enough grinding to get Final Burst!

* Minamimoto the first time around in ''TheWorldEndsWithYou'': a boss so difficult that nearly every guide suggests just setting the freaking game on easy mode. This troper power-leveled, and STILL wound up losing a few times before doing so.

* Even ''KingdomofLoathing'' has a member or two of this grand pantheon. The first, Baron von Ratsworth, is optional, but if you decide to fight him, he scales to your level, which is frustrating since level-grinding will actually just make him stronger. Defeating him on your character's first run through the game is incredibly hard. On subsequent runs or if you level up and get to access the Cola Wars Battlefield, it actually gets quite easy: get enough combat initiative to get the jump on him, then toss a Cola Wars Battlefield grenade at him. If need be, mop up with a strong enough guaranteed-hit skill.
* Duriel of ''{{Diablo}} II'', despite being only the mid-game boss, is probably among the most dangerous of them and easily the most frustrating. For some reason, the designers thought it would be great to pit the player against an enormously fast boss, with an aura that irresistably slows the player, in a bare room perhaps eight times his area. This in a game where hit-and-run is god; half the classes are explicitly designed for ranged combat only; and even the "tanky" Paladin isn't expected to last very long in toe-to-toe combat. Against minions, that is; he doesn't last at ''all'' against a boss. On top of everything else, you can't escape the room to catch your breath, even though you enter the room through a big hole in the wall

* ''{{Xenogears}}'' has several of that one boss throughout the game which makes it frustrating at times. The first one that comes to mind is the second fight against the Five man band hat fights for Solaris. What makes it hard is the fact that you first face two of them at one time. Then you have to face three of them next at one time and you don't get a change to heal before it. Then you have to face [[spoiler:Elly]] with all of the damage received fromt he previous battles. Redrum is another pain to fight. Not only does he have a move that will damage your party and heal himself at the same time, he also has a move that kills one character and heals himself at the same time.

* Macha in ''DotHack'' volume 4. She has an attack which charms the entire party without fail, meaning that all you can do is watch your team beat each other up and hope they snap out of it before you get a game over

* ''EternalSonata'''s first fight with Captain Dolce is not to be underestimated. Encountered after being separated from the characters that you have to use in her ship for an extended period, you're likely to be underleveled and Dolce will wipe the floor with you if you aren't prepared. She's faster than greased lightning, and packs a wallop and a half. Top it off with the fact that she comes with a pair of henchmen that will heal eachother if you don't kill them in one go and do some decent damage themselves.

* In ''TheWitcher'' [[spoiler:In the proper fight at the end of chapter 5]] Azar Javed qualifys. He will regularly blind or knock you down, both will disable you for a signicent period of time, only one of the two can be properly defended against (willow potions prevent knockdown), blind can only have it's effectivness decreased by spending a talent on an ability that stops it from working sometimes (and no other enemy in the game seems to use blind and silver level talents aren't something you throw away...). To make matters worse, if you made certain choices in the game, this battle has an escort who will die if you lose the bosses attention and he starts to attack them ([[spoiler:Brengar]] is really OverratedAndUnderleveled) and you have to start over if you want to save him (admitedly, this doesn't get you anything).

* Verminator in ''SecretOfEvermore'', whose devastating spells can wreak havoc on an unprepared party. Because he's up on a big stack of boxes, your melee attacks can't reach him. The only attacks that can hit him are spells, and charged spear attacks, so we hope you've raised up a spear a level or two.

* In Evolution: The World of Sacred Device, the final encounter with Eugene Leopold. The first fight with just him is somewhat of a pushover, but then cue him showing up in a HumongousMecha. What mainly makes him so dangerous is a machine gun attack he loves to use that hits the entire party TWICE, and can poison them with a high chance. And even then he takes a ton of punishment and will sometimes heal himself for 3000 HP. On top of this, he's ALWAYS be at or above the level of the main character, AND since you're forced to always use your StaffChick up until this point, [[FakeDifficulty you'll now be forced to have other means to heal and buff]] [[DistressedDamsel since she's been kidnapped.]] The main character can get some, but only if you've actually been exploring the ruins and not just rushing to the end of each one. And if you start the sequence to get up to the boss, [[PointOfNoReturn you aren't going back to town until you've beaten the game.]]

->''"Monsters strike first" "[=WarMECH=]: NUKE"'' \\
(A few lines of text later...) \\
''"[player] party perished"''
--> --'''A typical random encounter with [=WarMECH=]''', ''FinalFantasyI'' (NES version)

This page is for people to vent on bosses that gave them grief. They do not need advice on how to beat them. They already know how to find {{GameFAQs}}.

[[foldercontrol]]

[[folder: Final Fantasy]]
* ''FinalFantasy'' had WarMECH, as mentioned above. He could only be found through a long and useless hallway on the way to the fourth Fiend. Although he had half the HP of the final boss, he compensated by ''hitting twice as hard.'' This amounts to, if I'm not mistaken, hitting about 500 damage per turn to everyone in your party. This has made many gamers curse the heavens when they accidentally run into it and get destroyed in literally two turns, tops.
* ''FinalFantasyIII'' DS has Garuda. He's weak to Dragoon abilities, but you've just gotten the ability to become a dragoon, so there's a lot of level-grinding involved. He has the Lightning attack; a ridiculously strong attack that hits your entire party for high damage. ''All bosses'' in this game get two moves per turn, so even if you deck your your entire party in the best Dragoon gear you can find, put them in the back row for defense, and choose the Jump command for everyone, there's still the very real chance that Garuda will simply go first, use Lightning twice, and kill your entire party before you can move. Over and over and over again. One NPC says that a single Dragoon famously defeated Garuda by himself; some think that doing this in-game makes it easier. There is also [[spoiler:Doga and Unei]], who are faced in immediate succession, and [[spoiler:Doga]] likes using hard-hitting elemental spells while [[spoiler:Unei]] can turn you to stone, requiring the party to be quite strong to last long enough to defeat both of them. Some also consider Medusa and the Salamander to be this, for varying reasons; for example, the latter has a party-hitting fire attack that can kill your party in two or three hits. He enjoys using it twice in a row.
*''FinalFantasyIV'' has the notorious battle with Golbez in the dwarven castle; at first it's a HopelessBossFight, and one by one he picks off your party members, leaving only Cecil. Then, after a cutscene leaves you with two people, one of whom is the GlassCannon, he starts throwing every unfair trick in the book at you: shifting his elemental weakness constantly, becoming immune to everything else, cramming third-level magic down your throat with a status effect chaser... Oh, and special surprise, if Cecil is dead at the start of the fight (due to this fight immediately following another irksomely hard boss with no downtime whatsoever) then you just lost before you started.
** And then there's the Demon Wall. Capping the irritating Sealed Cave, it has no tricks. It simply pummels you into the floor, then begins to nail you with unavoidable OneHitKill attacks once enough time has passed. It's a massive stumbling block in ''normal'' gameplay; many a SoloCharacterRun has come to an untimely end on meeting the Wall.
** The Boss fight against the CPU. The Attack Node spams Laser Barrage.
* ''FinalFantasyV'' had Archaeoaevis, who had multiple forms, each with various resistances to the elements (the only notable weakness is Aero, which you can get from the local wildlife if you choose). Despite its relatively low HP at that point, its high defenses make attacks mostly futile; [[GuideDangIt however]], [[UsefulUselessSpell Lv5 Death]] work on him.
** Atomos is no slouch either. He has way too many hit points, and he casts a randomized damage spell that could scratch you or else immediately kill you. He pulls dead characters toward himself, and if they reach him they're ''permanently'' removed from the battle. He's a nightmare.
*** Until you realize that he '''doesn't attack at all''' when he's dragging someone towards him. In fact, if you ''do'' keep everyone alive the fight gets harder, as he will rapidly cast Comet on everyone. And given the fact that it takes him just under forever and a day to drag someone towards him, this fight is really just a cakewalk.
** The four crystals in the Forest of Moore aren't difficult at first, but when reduced below 3000 HP, they start using elemental spells, which often hit all party members, '''every turn''', making it quite difficult to stay alive.
*** They are vulnerable to Slow however, and several abilities/spells (Firaga, Titan summon, Coin Toss) along with careful monitoring of their HP can win the day.
* ''FinalFantasyVI'' had Wrecksoul, who has one of the most hated gimmicks in the game. He possesses a member of your party, leaving his two self-resurrecting cronies behind, and doesn't show up again until you kill said party member. This can go on for a long and infuriating amount of time.
** [[spoiler: [[ReviveKillsZombie Just use X-Zone, Wrexsoul dies immediately.]]]]
*** Defeating him this way won't award you the Guard Bracelet relic.
****And you can go to Cyan's Dream as soon as you get the airship. Before you get X-Zone. And you can't get out without killing him. A level 27. [[{{Tropers.Lilfut}} I'm]] going to have to start a ''new goddamn game''.
** In the Advance version of the game, we get the reborn Holy Dragon from the Dragon's Den. All the Eight Dragons have a gimmick. Holy Dragon asks for "Aid from Heaven". What this means is that he constantly casts Curaga on himself, for devastating high amounts of healing. He has a widespread Holy attack called Saintly Beam, in addition to Holy; Holy being the hardest element to defend against. Oh, and he loves to counter attacks with [[HPToOne Heartless Angel]], which he will often ''dualcast'' with Saintly Beam, which is an OHKO for the entire team.
* ''FinalFantasyVII'' had a toned-down version of the Demon Wall called Demon's Gate, but if you missed the Barrier materia, it was quite a ThatOneBoss in its own right. Not only does it look ''scary as hell'', if you're underleveled when you meet up with it, there are no monsters to level up with, because you're sealed out from getting to them. Without the Barrier materia, the fight was near hopeless.
** Carry Armor is another contender for FFVII's ThatOneBoss. He deals obnoxiously high damage to the entire party, and can permanently remove party members from combat, even from full health.
*** In Low-Level game (when you minimize the xp), Carry Armor is '''easily''' the hardest. Cuz, y'know, [[OneHitKill Laser Lapis]].
* Depending on who you ask, any of [[spoiler:Seymour's]] four incarnations in ''FinalFantasyX'', though Flux is likely the most common answer. Followed shortly after by another tough one, [[spoiler:Yunalesca]], but the amount of grinding a player likely had to do to beat Flux alleviates the challenge of the latter a bit, which is a bit of a GuideDangIt and violates your common sense. Both of these are nasty for the same reasons: they can one-shot your aeons, and love to drop Curse on you, meaning you can't hit 'em with [[LimitBreak Limit Breaks]], either. Meaning your main option is pretty much wail on them while trying to avoid getting [[ReviveKillsZombie ''Lifed'']] to death.
** Except Aeons get the first strike upon being summoned, so getting the overdrive bars on all your Aeons ready before the fight and unleashing them on Flux one by one will easily do him in. This doesn't work on [[spoiler:Yunalesca]] due to her three forms, though.
** Flux -- and in fact, any one of [[spoiler:Seymour's]] forms -- can be easily handicapped. [[spoiler:Poison is your friend. Have Lulu use Bio. Or Rikku can mix up a Calamity Bomb with Musk and a Power Sphere.]] But you're right, he is a bit of a nightmare, if only for that ONE attack that will wipe you out unless you scrabble to get Protect/Shell cast on your party RIGHT before he does it.
** The real problem with [[spoiler:Yunalesca]] is that her 3rd form gives a [[SadisticChoice pick your poison]]. Throughout the fight, she uses a move called Hell Biter that inflicts zombie status on your whole party, which causes healing items and white magic to have the opposite effect. If remove the zombie in the first two forms, you will be okay until uses Hell Biter again, because the only way she inflicts any real damage is by casting white magic on your zombie characters, which she will do even they don't have zombie status on them. Her 3rd form, however, has this attack called Mega Death, which is an instant death attack on your whole party. Unless you have armor that protects against instant death, the only way can get around it is by leaving characters in zombie status, meaning they will get hurt by her white magic, and you can't heal them except by reviving them after they die.
** Quite surprisingly, not many players remember the boss just ''before'' Yunalesca. The battle is fought on teleport platforms, the boss counters all attacks, casts berserk constantly and activates high damage mines under the platforms. Not remembering that the bossfight exists can be quite aggravating because of the lack of preparation and the way the battle is fought. The boss is pretty strong too, a moderately leveled party can still get their asses handed to them in a flash.
** There's also Evrae, the boss you fight as you drop into Bevelle. Kinda comes across as a GiantSpaceFleaFromNowhere, as he's introduced two minutes before the fight, and never mentioned again in the game, except when fought for the second time. Which is even more of a Giant Flea fight than the first time.
*** What makes this flyer so hard is that you have no aeons, all magic spells are halfed, and this boss is one of the few enemies that can use [[SuperSpeed the Haste spell]] on itself. That, and his [[TakenForGranite petrification breath attack]] does ''not'' help at all.
*** Furthermore, he loves his poison breath attack, which brings the hurt immediately and will continue to do so until the poison affliction is relieved. Bright side is that you realize the what good in all those friggin' Al Bhed Potions you'd been picking up in the Sanubian Desert was.
*** Actually, Evrae is very easy the second time around if you take into account that it's undead. That's right, it has the "Zombie Status" inflicted on it. Throw a couple of revives at it and it's history.
* The ''Chains of Promathia'' expansion of ''FinalFantasyXI'' throws several of those at the playerbase. Three dungeons called Promyvion with bosses that like to use all the worst status ailments such as sleep, curse or just plain high damage are required to even start that particular storyline. While, with the right party set-up, strategy and preparation, all three can be beaten in one evening, assembling a party willing and able to follow a strategy is a feat in itself, especially if everyone in your linkshell has already beaten the story and is too lazy to help out and you are dependant on pick-up parties more often than not consisting of people who just started playing.
** While Promyvion is merely a siphon to filter out the unworthy, the later three-part boss battle against a group of Mammets, Omega AND Ultima still routinely destroys the statics that made it this far.
** Also the four magic pots right before the final battle of the storyline.
** While Absolute Virtue qualifies more as a ''BonusBoss'', he deserves a special mention for being ''ThatOneBoss'' who managed to make the entire playerbase give up on defeating him.
*** This needs additional explanation. Except for exploits for which players were later banned, Absolute Virtue has NEVER been defeated. One team went on for 19 hours before giving up. It doesn't actually have much health relative to many other bosses, but he can use 2-hours as often and fast as he wants. For non-XI FF players, that's like having constant limit breaks. The worst is Benediction, which heals him to full health instantly. He will use it. Frequently. The dev's say he's a puzzle boss. In reality, he's a GuideDangIt with no guide. The entire community has given up on defeating him. When teams take down the boss before him, they designate one person to sacrifice himself pulling him away so the rest can survive.
* Tiamat from ''FinalFantasyXII'', who got a big power boost from the last boss that the party fought, making her very difficult for a normally-leveled party. It's arguable whether she or the Elder Wyrm, which comes up a short time later, is FFXII's That One Boss, but because the Elder Wyrm is skippable, Tiamat gets the credit.
** While Elder Wyrm is technically skippable, trying to skip it involves going through an area where the enemies can kill you in one or two hits at that point in the game. Plus, Tiamat doesn't have Sporefall (which inflicts almost every negative status on the party).
*** But skipping Elder Wyrm through that killer area isn't that hard if you do it right. [[GoodBadBugs Because the PS2 doesn't have the power to keep track of too many friendly/enemy objects at a time]], you can Immobilize a teammate at the entrance to the area and run into the area without them. The game won't keep track of enemies too far away from the team, so by switching to the Immobilized teammate (who should be miles away from the rest of your team) and switching back, all the enemies will disappear, leaving you free to skip Elder Wyrm with ease.
* The sequel to ''Final Fantasy XII'', ''[[FinalFantasyXIIRevenantWings Revenant Wings]]'', had two bosses in this category: [[spoiler:Balthier]] and the battle against [[spoiler:Mydia in Feolthanos' keep]].
** ANY fight against [[spoiler:Mydia/Judge of Wings]] is more like a brick wall than anything else, requiring several hours of leveling up in order to defeat.
* ''FinalFantasyXIII'' has [[spoiler: Cid Raines]], although the enemies afterward were stronger than this, this particular boss is exceptionally difficult at the time you are required to face them.
** It also has Odin, who is hard thanks to unrelenting attacks that can take out Lightning in the very first chain with no chance of healing, plus the Doom counter that is placed on the party leader during all the Eidolon fights. Players taking more than 10 tries to defeat Odin is not unheard of.
** Then there's another eidolon fight, Hecatoncheir, who has EXTREME damage-dealing potential and leaves you next to no openings to attack unless you've covered yourself with buff smokes beforehand. Having to fight him with only two party members way after the point when the game lets you pick your own party doesn't help much. Oh, and the Doom counter is still here, if you're wondering.
** Hell, most people will find at least one Eidolon that will make them rage. Odin and Hecatoncheir are just the most prominent. Personally, this troper had far more trouble against Sazh's Eidolon, Brynhildr. It's attacks aren't powerful enough to one-shot you, but it can be incredibly annoying as it can take off a good chunk of your health, forcing you to switch to a team with a Medic. And your party, as with the Hecatoncheir fight, has only two people. And, of course, the [[RunningGag Doom counter is in effect.]]
** No mention of Barthandelus? To really damage him, you have to get rid of four helper things which are blasting you with powerful magic that can and will take your health down if you don't get a Medic into the fight quickly. And once you take out those, you still have the main face to deal with. He also has an attack called Destrudo, which is essentially a one-hit kill if you don't weaken it.
*** Uh... every piece of armature is weak to one element and casts another. Combat Clinic paradigm (med/sen/med) and a Synthesist with Bar- spells (like Hope) makes this fight trivial. At this point of the game, you're supposed to have strong enough grasp on the paradigm system to be able to switch between offensive and recuperative modes at a moment's notice. It's more of a late [[WakeUpCallBoss wake up boss]] than a that one boss.
*** But the fact that the way to weaken his one-hit kill attack is a bit more of a GuideDangIt situation, he can be a bit of a That One Boss
**** However, his 'one-hit kill attack' can be avoided if your party leader is Lightning and you have the proper timing. Then again, so can every other attack in the game.
** How about Alexander? Your party consists of Hope, Lightning, and Fang. Hope's HP is probably the lowest of the three. Hope is all the one you control, and if he dies, it's [[WeCannotGoOnWithoutYou game over]]. Alexander's first attack has a wide enough radius that it will probably hit all three of your party members, knocking them down in the process. His second attack comes fast enough that your party will barely be standing up again, meaning that you haven't had a chance to heal, so that it will very likely kill Hope. Game over. Also, if you do survive to fight further, the Eidolon Doom counter is, as always, ticking away.
** ''Aster Protoflorian'', MY GOD... ''Aster Protoflorian''
*** To elaborate on that, Aster Protoflorian is one of those bosses who likes to switch up its elemental weakness. That's not much of a problem in this game, since you can chain together different elemental spells at once anyway. However, you're fighting it with only two party members, Lightning and [[SquishyWizard Hope]], and it possesses at least one attack that can hit both of them at the same time, dealing massive damage for this point in the game. Both of your party members have access to healing spells, but without any Sentinels, you have no real means of defense beyond spamming Cura and Phoenix Downs every time your health dips too low, hoping it doesn't spam its more powerful attacks till you're dead.
***Actually, that boss is quite easy if you're liberal with switching between dual ravager and ravager/medic. The thing that makes him annoying is just how incredibly long the battle lasts. This troper spent literally 20 minutes on that fight.
** Bahamut. Oh dear sweet heavens, Bahamut. First, you're stuck with probably the worst possible party to fight him unless you've been tricking everyone out the whole game up to that point. Then, there's the doom counter again. Finally, there's Bahamat's three hit combo of doom, which knocks whoever it hits into the air, making them unable to act for the entire duration of the combo. The combo can hit everyone in it's radius, and if it hits twice in a row on the party leader before you can heal, game over man, game over. Of course, when he's on your side, the combo isn't quite as effective on enemies as it was on you.
*** So, in a nutshell, just about ''any'' Eidolon battle in this game is a contender for the game's most challenging boss.
** Dahaka, the boss of Taejin's Tower. For most of the fight he seems easy-going, until he decides to whip out his elementally-themed attacks, which hit the entire party [[ForMassiveDamage for MASSIVE DAMAGE]]. Survive these and knock him down to less than half health, and he pulls out his OHMYGOD nuke, Aeroga. If you haven't been grinding your whole way here, this is a one-hit knock out.
*** He also has an attack that inflicts every status ailment on your party. You can probably survive it if you have TP left for Renew, but otherwise, you're stuck switching to a paradigm with healers and spamming Esuna while your Sentinel acts as a meatshield for your Medics.
* The most absurd fights in the Game Boy game ''Final Fantasy Legend II'', are with the "TianLung" and "Fenrir" mini-bosses you encounter in the dungeon between Apollo and Arsenal. Winning either of these fights is essentially a LuckBasedMission, because depending on the whim of the Random Number Generator, the battle may be against either one, two, or three copies of the monster. They almost always act before your characters, and their "Tornado" attack hits every member of your party for for more than 600 damage in a game where the Max HP cap is 999. An encounter with two or more is basically impossible to win.
* Final Fantasy Legend III (aka SaGa 3) is perhaps even ''more'' brutal than the sudden difficulty spikes in Legend II. Agron takes the role of ThatOneBoss of the game fair and square. You think several other bosses like Chaos and Ashura are rather large difficulty spikes? Well think again...Agron not only comes very late in the game, but for the past five or so hours of the game (Depending on how much you spent leveling in the Purelands), you had a GuestStarPartyMember with you. (Faye or Dion)
* ''FinalFantasyMysticQuest'', despite being probably the single easiest game in the FF series, has Medusa. Medusa can paralyze and petrify the party. Now, there is an item that cures all status ailments... but this is counterbalanced by how your party is ''two people''. If she's faster than you are and hits you with petrification, you're done.
** Pazuzu could also count, since he uses Psychshield to reflect magic. If he goes first after you order a spell, or if you just plain [[GuideDangIt don't know what it does yet]], Psychshield will reflect the spell. And odds are you're casting Aero to hit his weakness, so the reflected attack will do over 1000 damage to you resulting in an instant kill. Later on Pazuzu's reincarnation, Zuh, also has Psychshield, along with an Instant Death attack. Goodie.
* ''FinalFantasyTactics'' has this in a few sticky points: [[GuideDangIt unless you know what you're getting into]], the ''solo'' fight between Wiegraf and Ramza is a good way to force you to restart the game. Wiegraf's got an at-will blast attack that deals just under half your HP if you're a tank class, the ability to heal, height advantage, and the generosity to fight you in a small, cramped arena where you can't run from him to heal up and swing back. And no, you can't go back and grind or even ''shop'' because you're locked into the next mission. Oh, and if you win, you get to fight [[OneWingedAngel a powered up version]] who has a gigantic, area-affect summon and minions who can use one of the strongest spells in the game at will....
** The fight at the Golgorand Execution Site fits here nicely as well. You get to fight Gafgarion, tough by himself as he damages you and gets HP back with his signature attack that doesn't cost any MP, and other ennemies, specifically two Time Mages which will happily status effect your people. You also start out divided into two groups, the second group popping up right in range of said Time Mages. At least there is one (''one'') random encounter map open because that fight blocks your access to the rest of Ivalice. If you are not prepared, be ready to get to know that map. Very. Well.
** Elmdor and the Assassins on top of Riovanes Castle. Enjoy your rage as Rafa blindly charges into the Assassins and is instantly killed by Stop Hand.
** There are a few tactics (or more accurately, a couple of variations on the same basic tactic) that can allow you to trounce Wiegraf (and incidentally leave you in a position to turn the follow-up fight against his demonic into a CurbStompBattle) with the right preparation. If you pull it off, you can [[OneHitKill oneshot]] Wiegraf. But given that some of the preparation has do be done ''mid-battle'' (and over the course of many turns), you still need some luck on your side, and a single misstep can still doom you. If you've already played through the game at least once, you'll have the added frustration of knowing that ''very'' shortly after this battle, Ramza will gain access to a new ability that would've made Wiegraf ''much'' easier to beat.
*''FinalFantasyIX'' - If you don't know what you're getting into and aren't well-equipped for the fight, the Earth Guardian can be one hell of a boss. You're stuck with a character most people haven't really worked with (because said character has been gone for about 70% of the story up to this point), and while it's possible to win the fight with Zidane alone, it makes for a long and difficult fight if you can't snag a [[LimitBreak Trance]] in a pinch.
** See what happens when you try to blaze through a game with just your "A Team" and don't take the time to train all your characters, boys and girls?
*** Not really. Earth Guardian is hard, but leveling Quina up will take ''hours''. Just give Zidane Auto-Potion, Gaia Gear, and put him in the back row while spamming Thievery. Now is the time to use those Elixirs. This is the very last time in the game that you ever have to use anybody but the team you want.
**** Use a tent on him (or use Quina's Bad Breath), and it becomes really easy.
* This troper can't remember the name of it, but that one monster you fight after completing the Cactuar sidequest in ''FinalFantasyX2'' definitely counts. Seriously, how the hell are you supposed to beat this thing when it has 300,000 HP, 9,999 MP, the ability to resurrect its body parts if you kill them, and a series of brutal attacks and status problems ''without'' LevelGrinding to the point where the rest of the game is no challenge?
*Adrammelech in FinalFantasyTacticsAdvance has a powerful attack hits anything in a line between him and the edge of the arena, which is especially bad given that the arena is a long, narrow one, with your party and his group on opposite ends. He also comes with three dragons who are quite powerful, and it's difficult to kill him without killing them first.
[[/folder]]

[[folder: Pokemon]]
Anything at all which uses even the most basic strategy against you in this series is prime material for this trope, since the game mechanics all but guarantee that barring ungodly levels of GenreSavvy and foresight ''you'' won't be using any strategy at all until very late in the game. Your party is basically a RagtagBunchOfMisfits, composed of whatever itty bitty critters you manage to cross paths with; you have a very vague idea of how powerful they are at the point you catch them, let alone of whether they'll be viable later (they might easily be Vendor Trash that will become horribly outclassed). You're restricted to using whatever dubiously effective attacks these guys will be learning by level up and [=TMs=] you can get your hands on, which means even if your Mon learns something potentially useful, chances are you'll discard it as it will be indistinguishable from the myriad other completely useless moves it'll be trying to learn. So your cunning battle plan nearly always consists of LevelGrinding, hoping your Mon learns something useful like [[StandardStatusEffects Confuse Ray or Thunder Wave]], then having it spam its most powerful attack. Which, if your opponent is using any strategy at all, is in all probability only going to work if you manage to gain the [[ElementalRockPaperScissors Type Advantage]]. Which translates to hoping you already have the appropriate Mon for this, because you are not ''really'' going to catch some new Mon now entirely for this purpose and waste hours of your life raising the thing dozens of levels. So there you are and this is what you have to work with, and suddenly the game throws these guys at you:
* [[NightmareFuel Sabrina]], at Gen 1. Not only is she packing a team of psychic-types, but her Pokemon are fifteen to eighteen (depending on which version you're playing) levels higher than the last gym leader. The fact that Psychic was extremely overpowered in Gen I certainly didn't help any. You might have watched the Anime and learned that Psychic-types are weak to Ghost-types, and thought yourself very clever for catching a Gastly, the only available Ghost-type, to use against Sabrina. In that case you were probably dismayed to have it knocked out in one hit. Because it, and its line of evolution, is also half Poison-type, which means weak to Psychic-type attacks. Oh, and possessing of horrid HP and defenses. In addition to this, there was a stupid bug in R/B/G/Y where Ghost-type moves had no effect on Pyschic-types and Ghost pokemon weren't even strong defensively against Psychic-type like they were said to be. Even if they were, the only Ghost-type moves in Gen 1 were Lick, Night Shade and Confuse Ray. Lick has a power of 20, Night shade has fixed damage (and is thus not applicable to the type advantage multiplier) and Confuse Ray does no damage.
** In fact, the developers intended that you skip her and fight Koga first. Either due to oversight or intention, it's possible to [[SequenceBreaking Sequence Break]] for the fifth through seventh gyms (Koga, Sabrina, and Blaine) and end up fighting Sabrina much earlier than you should be. In later generations the introduction of Steel- and Dark- types (resistant and ''immune'' to Psychic-type attacks, respectively) would have made this fight anywhere from still as horrible to a walk in the park for the player, depending on whether they had the foresight to train a Mon of these types in advance.
* Whitney, from Gen II, the Normal Gym leader and the third "boss". While her Mons have no strengths against any specific elements, she more than makes up for this with her Miltank. It has an attack called "Rollout" which gets stronger on subsequent use, and if it [[IncrediblyLamePun gets rolling]], you're dead. And god forbid you picked Quilava for your starter, who's weak to Rock-type attacks. However, if you [[GuideDangIt know about the trade to get Machop...]]
** HeartGold / SoulSilver: [[http://img193.imageshack.us/img193/8743/371291f8e8d1bb41e308baa.jpg STOMP IS THE NEW ROLLOUT]] (stop flinchaxing my Combusken you stupid cow!). What, you've overcome the flinchax? Too bad, the cow had used Attract on your male Mon which is now in lurrve and won't attack. What? Did you try the same trick that pulled you through in the original Gold and Silver, catching a [[GlassCannon Gastly]] to nullify Miltank's physical attacks? Guess what! Miltank now has the ability "Scrappy" ([[TheScrappy how appropriate]]) which allows it to hit Ghost-Types with Normal-type attacks. As you can see, it's pretty much a rule of thumb that Sending Out a Gastly Never Works. So in desperation you set out to somehow make The Cow slower than whatever you have out, which nullifies Stomp's 30% rate of causing you to flinch and skip your turn. No luck, mate: That Mooing thing is most likely faster[[hottip:*:higher base speed than ''Rayquaza''?! How the hell does that work? Also, it carries a Lum Berry; so much for your cunning plan of paralyzing the thing]] than anything you have up to that point (bar trading), and has hideously high defenses for that point of the game, and...
** Yes! You've already made Whitney go through a super potion! Your Mon may be nearly dead, flinched to oblivion and desperately in love, but Miltank is nearly disposed of! Surely victory is within your grasp!- MILTANK USED MILK DRINK? MILTANK REGAINED HEALTH?! What is this I don't even
* Also in Gen II, Bugsy. If your starter was Chikorita in GSC, you most likely were gritting your teeth in frustration; even if you were smart and caught a Flying-type, you were still pitted against a relatively high-leveled Scyther that knew Fury Cutter (aka: Rollout lite, for bugs). For HG&SS, Scyther has the ''Technician'' Ability and Fury Cutter gets '''STAB''' from it. IfMyCalculationsAreCorrect, the power sequence goes thus as 22, 44, 88... Kinda makes you feel good that the move was [[{{Nerf}} replaced]], right? No. They gave Scyther ''U-Turn'', which has a base power of 70 ''and'' takes Scyther off the field to protect him from retaliation, instead. Even if your Pokémon is at Level 24, at that point of the game if it gets hit for super-effective (Chikorita, Hoppip, Slowpoke) it's fainted, period.
** Luckily, Metapod and Kakuna, which are Bugsy's other two pokemon, are jokes, knowing only Tackle or Poison Sting respecively. Enjoy your [[ExperiencePoints free EXP]].
* Morty, Gen II's 4th Gym leader. Remember how Sending Out a Gastly Never Works? Well, to be more precise, ''you'' sending out a Gastly never works. This guy has Gengar which is what Gastly eventually becomes when you've actually bothered to train it instead of backtracking, picking it up and hoping its immunity to Normal- and Fighting- type attacks will magically do away with the trouble you're having. Some exact stats for this species of Pokemon: SPEED- don't bother, it'll move first unless you inflict it with paralysis; SP.ATTACK- if you do not have [[StoneWall Umbreon]] or something you may now start crying. Brought in a Psychic-type to pull that whole Sabrina situation, only this time in your favor? Yeah, that thing knows shadow ball. That actually IS effective against Psychic-types. So you're better off bringin in some other Mon, which Gengar will in all likelihood use Hypnosis to put to sleep, then hit with Dream Eater, the most powerful Psychic-type attack in the game. Refer to that thing's SP.ATTACK stat from earlier and note that half the damage dealt will heal Gengar. Figured you'd switch out? Nope, it knows Mean Look. If that sleeping pathetic wreck over there having its dreams munched on was your only hope of defeating Gengar you'll have to use a revive. Which at that point of the game is a strategy that will get you bankrupt.
** So how could Gengar become any more of a pain to deal with? Well, hypothetically, if they gave him some sort of levitation ability that nullified his weakness to Ground-type attacks and made him immune to them instead. Or maybe if they made shadow ball a special-based attack so it would run off of Gengar's SP.ATTACK, thus causing more damage than dream eater ever did without your Mon even having to be asleep. Oh, wait. They did both of these for the remake. Have fun.
* Clair, the 8th gym leader from Gold/Silver/Crystal. She was usually (if you had a well balanced team, that is), 3-5 levels higher than you, which would be fine if she weren't so insanely hard to match types with, because Dragon only has 2 weaknesses: ice and dragon. This left you with basically 2 options, both of which are insane level grinding, and neither of which make your victory ''easy'', just possible. Then she has the gall to not give you the badge after you survive hell. Oh yeah, and the only place to get an Ice-type at this point in the game? The Ice Path you just came out of. Any Jynx, Swinub, or Delibird found in there is likely to be more than several levels lower than a well-balanced team. In fact, her final Pokemon is a Water/Dragon type, meaning it's ''only'' weak against Dragon-types. Unless you got a Dratini from the Goldenrod Game Corner, you have absolutely no access - save trading - to Dragon-types whatsoever at that point in the game.
** And even suppose you ''did'' get that Dratini and decided to send it out against Clair. Think about that stroke of genius for a minute. Yes! Your Dragon may now take advantage of the incredible damage Dragons may inflict on other Dragons! Wait, ''So can her dragons''. Way to go, Einstein.
** Clair, and by proxy, Lance, get even worse in the remakes, where they will now spam moves like Thunder and Hydro Pump, high power moves that are supposed to be balanced out by low accuracy and limited use (PP). Only when they use it, it's 100% accurate and has infinite usage. At least Red took one for the team and bothered to have a Mon constantly make it Hail to justify Blizzard always hitting...
** Even WORSE, at one point you can fight a double battle against BOTH Lance AND Clair, with your Rival "supporting" you... only not, since your Rival is absolutely pathetic and will quickly die, leaving the battle up to you.
*Flannery from the 3rd Generation, but mainly her Torkoal. You obliterate her Slugmas, and are feeling fine. But then comes the Demon-in-a-Half-Shell Torkoal, which promptly melts you with Overheat if you have anything but a water-type out. But not even a water type can hold up to Torkoal, with it knowing Attract and Body Slam, which somehow always paralyzes. Then Flannery decides you still haven't had enough and uses Sunny Day. I LOST TO A TURTLE!
* Norman from the 3rd Generation, for those who didn't pick Torchic as their starter. This guy is only the fifth gym leader, yet he has ''two'' Slakings, which have the highest attack stat of any non-legendary Pokemon up to then and a ton of HP. Even though they can only attack every other turn, they are still capable of KOing a Pokemon in one hit. He also has a Vigoroth, which is less powerful but incredibly fast, able to attack before most other Pokemon you probably own. Finally, all three Pokemon come equipped with Facade, an attack that ''doubles in power'' if the user is poisoned, burned, or paralyzed. So if you're trying to break him with stuff like Thunder Wave, he'll just throw attacks at you that are only 10 points weaker than a ''[[DangerousForbiddenTechnique Hyper Beam]]''; and that's not counting the bonus Slaking gets from being the same type as Facade.
* Tate and Liza in Emerald, which doubles as a very nasty shock to anyone who played Ruby or Sapphire. The battle was [[CurbStompBattle absurdly easy]] in the earlier games, and undoubtedly the average player expects more of the same...
** To elaborate: In Ruby/Sapphire, the only Pokémon the pair had were Solrock and Lunatone, easily taken out with a few good Dark-, Grass-, or Water-type attacks. In Emerald, you first need to fight through a Xatu (which can either use Confuse Ray on your fighters or Calm Mind to jack up its stats, aside from flat-out attacking with Psychic) and a Claydol (which spams Earthquake and Ancientpower). If you do manage to get through those two, you'd think Solrock and Lunatone would be pieces of cake, right? NOPE. It's not uncommon for Xatu to use Sunny Day before biting the dust, so Solrock can either hit with a powered-up Flamethrower (in case anyone would try to use Shiftry or Cacturne) or skip the charging turn to attack with SolarBeam (say goodbye to Sharpedo and Crawdaunt). For those not keeping track, the only Dark-types (the ideal choice, being immune to Psychic attacks) left at that point in the game are Absol, Mightyena, and Sableye. Did I mention Claydol uses [[GameBreaker Earthquake]], which hits every other Pokémon on the field and which the other three Pokémon on the Leaders' team are all immune to? None of the three aforementioned Dark-types have stellar Defense stats.
* Wattson in Emerald, if you didn't pick Mudkip for your starter. He will Shockwave all of your Pokemon into submission before you can even attack.
* Volkner in the fourth generation. It seems like they expected you to level up about ten levels in between the seventh and eighth gyms, even though the two are so close to one another.
** If your using Platinum and you've got a Torterra, and your Torterra can use earthquake, he is much easier. You've also got the whole Distortian World thing with Team Galactic between him and Candice to help level up. But if you've got Diamond and Pearl, you're on your own, especially since two of his four Pokémon aren't electric types.
* Pokémon Colosseum's Cipher Admins; this isn't so much because they were difficult to defeat but because you had to spend ages trying to capture the legendary beasts WHILE keeping ''yours'' alive. Especially Ein...oh god, despite being nearly ten levels up, that Raikou's Thunderdance combo really freaking HURT.
** The second fight with Snattle in ''XD'' also hurts quite a bit if you don't have the right number (or quality) of sweepers. Why? That goddamn STARMIE. It hits fast, hard, and if you haven't been dragging a tank of a Shadow Pokemon around to soak up the damage, it can wipe out an entire (non-Shadow) team. It's Shadow Solrock partner, by contrast, is almost insultingly easy after that thing.
* Those bloody group bosses in ''[[PokemonMysteryDungeon Pokemon Mystery Dungeon: Explorers of Time/Darkness]]''. I'm talking to you Luxio tribe, [[spoiler:Dusknoir and Sableyes]], 'The Grand Master of All Things Bad' and their cronies.
* Pokemon Stadium 2 brings us Janine. She's easy in Round 1, but what's her strategy for Round 2? Baton Passing multiple layers of Double Team (a move normally banned in competitive play for being [[LuckBasedMission too luck-based]]). All her Baton Pass targets can take a few good hits, have Confuse Ray, Attract, or Swagger to screw with your chances of hitting even further, and will wear you down with Toxic and Sandstorm. If you're planning to just switch out, take note that she's also packing Spikes and Mean Look. She will slowly torture you to death unless you come prepared with Haze and Heal Bell, but even then you're still at the mercy of many elements of luck.
** Let's be blunt: R2 makes everything ThatOneBoss, because it jacks up the [[TheComputerIsACheatingBastard CPU's cheating.]] Witness items activating repeatedly, probability screwing you over, and all sorts of other cheap tricks.
* In Pokemon Diamond, Pearl, or Platinum, Fantina is probably one of these to anyone who starts with Chimchar. Her Pokemon have powerful Psychic-types moves that can easily mess your Pokemon up pretty badly. And in Platinum, her first two Pokemon are pretty easy, but the Mismagius can easily wipe you out.
* In Pokemon Emerald, there's an area called the Battle Frontier which hosts seven different battling facilities each with their own set of rules and conditions. By far the most intimidating of these was the Battle Palace, where you were ''forbidden to give attacking orders'' to your Pokemon. Instead, you would select the command to attack and your Pokemon would choose an attack that corresponded to their nature. You could assemble a team with the hardest hitting attacks in the game and get beat in the first fight without landing ''a single'' hit because those attacks were incompatible with the Pokemon's nature. In some unlucky cases, a Pokemon would use an ineffective move. In some extreme cases, their attacks and nature would be compatible but they would stay idle while the opponent wailed on them. Then there's the Battle Palace's "boss" Spencer, who had a Crobat, a Lapras, and a Slaking.
** To make the player's life even more miserable, his Pokemon were decked out with horrifically overpowered move sets designed to make you hurt yourself and waste PP. Crobat had [Fly, Double Team, Confuse Ray, Toxic], Lapras came equipped with [Ice Beam, Confuse Ray, HORN DRILL, Protect], and Slaking got [Swagger, Earthquake, Brick Break, Shadow Ball]. Basically, he had every base covered and then some. Note that all of his Pokemon have a move which confuses your own, adding further frustration to an already heavily luck-based form of battling.
* [[CompleteMonster Cyrus]] from Gen IV. Gyarados used waterfall! Bam, you're dead. All right, reload. Let's send out an Electric-type Mon. Gyarados used Earthquake! Bam, you're dead. Hmm.
* Karen of the Elite Four in HG/SS. Houndoom flinches you with Dark Pulses which are super-powered, because it had earlier used nasty plot. Half your team dies. Oh, look here's your friend Gengar again. Ha! Finally brought it to within an inch of its life! It dies next attack!- [[TakingYouWithMe DESTINY BOND]]? FUUUUUUU
* So, yeah, a FinalBoss is by definition not ThatOneBoss. Still, have fun dealing with [[spoiler:Lance]] from Gen II and his rampaging army of [[InfinityPlusOneElement Dragonites]]. Also have fun being target pratice for [[spoiler:Cynthia]] from Gen IV who has Perfect [=IVs=] on everything and Milotic with Mirror coat and that cheap Surf/Ice Beam no-type-resistance-for-you gig and a [[GameBreaker GARCHOMP]]. And let's just not get started on [[spoiler:Lance]] when you rematch him and his [[LightningBruiser Lv72 LumRest!Salamence]], [[GameBreaker Lv72 Garchomp]], [[LightningBruiser Lv75 Dragonite]], [[TakingYouWithMe Lv73 Altaria]], Lv68 Charizard, and Lv68 Gyarados, all of which he will switch between to mess with you and constantly spray Full Restores on. Just be thankful that you don't get to rematch [[spoiler:Cynthia]]- God only knows what they would've dreamt up given ''that'' opportunity ([[OlympusMons Rayquaza? Arceus? Mewtwo?]])
* All of that said, a special honorary mention goes to a certain trainer in Gen I's Mt. Moon who had a level 16 Raticate. With Hyper Fang. Never mind the fact that level 16 is the highest you have seen at that point and that getting hyper-fanged by a [[ComMons RATTATA]] at that level would have still hurt, and you get... that THING. Thankfully, it was fixed in Yellow.
* Another Generation III gym leader. Winona. Not only does EVERY MEMBER OF HER TEAM KNOW AERIAL ACE, by this point in the game ''none'' of your own Pokemon probably know it, and that move is a real annoyance unless you have a Steel type in your party, due to them being damage sponges.
** Except Magnemite are readily available at that point of the game...
* Flint, in Diamond and Pearl at least. So your geared up with your water- ground- or rock-type Pokémon, ready to stomp those fire-types of his. But then you find out that ''three of his five Pokémon'' aren't fire-type. Platinum was much nicer to us about it, though, giving him a full team of fire-types.

[[/folder]]

[[folder: World Of Warcraft]]
''WorldOfWarcraft'' has had plenty of these over the years throughout the game world and dungeons. Although patches have tweaked some encounters to mitigate the most frustrating components, and the increased level cap with each expansion has rendered older content more or less irrelevant, many bosses are still quite memorable for their ability to destroy unprepared players. It's worth noting that the difficulty of many early raid bosses led directly to the adoption of [[CrazyPrepared preparatory measures]] which even Blizzard developers did not anticipate but which would later influence their own game design philosophy -- such as flasking the entire raid (using high-end potions that were so difficult to craft in the original [=WoW=] that they were universally considered TooAwesomeToUse). Nowadays, flasks are cheap and expendable, mostly due to said "arms race" effect.

'''REMINDER''': Hard modes, being optional, count as {{Bonus Boss}}es.

* The original ''World of Warcraft''
** 5-man dungeons
*** Arugal, the last boss of Shadowfang Keep, can immobilize your party then teleport away to attack them with Shadow Bolts, and can also turn one party member into a werewolf that attacks the others, making him exceptionally difficult for his level and considerably different from other bosses.
*** Archaedas, end boss of Uldaman, is a major step up in terms of complexity from anything previously encountered by players while leveling because of large numbers of adds that swarm the other players and heal the boss. There's also the fact that he was level 47 while the dungeon could be entered as early as level 38. The difficulty curve was tweaked in a later patch.
** [[LethalLavaLand Molten Core]]
*** Majordomo Executus was considered a massively difficult encounter due to the need to coordinate the simultaneous tanking and crowd control of nine separate mobs -- this in addition to the harsh requirements to summon him in the first place.
** Blackwing Lair
*** Razorgore, the first boss of Blackwing Lair, requires tanks to pick up and kite potentially dozens of adds before the boss can even be fought, while healers do everything in their power not to attract attention. Many Molten Core/Onyxia level guilds simply folded on this fight.
*** Immediately after Razorgore comes Vaelastrasz, an absolute balls-to-the-wall slugfest on a short timer where one mistake with aggro can wipe the raid. Vael was renowned as a guild killer back in the day. Keep in mind that Razorgore and Vaelastrasz were not simply the first two bosses in Blackwing Lair--they were the first two ''encounters'', as well as the two hardest bosses in the instance (only Nefarian himself comes close)! This is a textbook example of how not to build a dungeon, because while Blackwing Lair was very impressive, most players never got a chance to see it because of Razorgore and Vael.
*** Another boss is Broodlord Lashlayer: If your tanks weren't in essentially the very best gear possible, they would probably die to Mortal Strike because it could crit for 8k on plate. You'd likely need multiple tanks with great gear because Broodlord uses a knockback that reduces the target's total threat by 50%. If you're melee and you ripped aggro, prepare to die. If you're ranged and you ripped aggro, you better run in and die fast otherwise Broodlord will cleave and kill your ranged/healers. Then if you wipe, have fun reclearing the Suppression Room; easily some of the worst trash in the whole game.
*** Nefarian himself is not that difficult, but his encounter is made more challenging by another vicious adds phase before you get to fight him, and a GameBreakingBug in the initial release that sometimes made it impossible to fight him again after a wipe.
**** Although some of his class calls weren't very dangerous, others could be very nasty. Priests didn't stop their heals before a class call and if the call was Priests? Now their heals will start killing people. A Rogue call would root Rogues right in front of Nefarian. Is your tank too lazy or too stupid to shift Nefarian to the left or right? Congrats, all your rogues will die to Cleave. For Shamans, Nefarian gains all totems and effectively drains Shaman mana. This also means that Nefarian gains Windfury. On a Mage call, Mages randomly spam Polymorph on the raid. Typically, this call wasn't too awful, but some bad luck in your favor could turn a Mage call into a potential raid killer: Polymorph on the MT, raid wide fear before the Priests/Paladins can dispel it, then Nefarian begins to kill off your raid.
** Ruins of Anh'Qiraj
*** Ayamiss the Hunter deserves special mention due to the tendency of players not familiar with the fight to accidentally aggro him before the room was cleared of trash or the raid prepared.
** Temple of Ahn'Qiraj
*** Princess Huhuran is a gear-check boss, requiring insane levels of Nature resistance and near-perfect timing. Any less and you might as well not even attempt her.
*** Immediately after Huhuran in Ahn'Qiraj comes the Twin Emperors, a sheer coordination and teamwork fight that can still frustrate players ''two expansions later'', due to the fact that without precise tanking they simply heal each other to full within seconds.
*** C'thun was brutally hard in his initial version, mainly due to the fact that he would cast his raid-wiping Eye Beam attack without any delay for players to enter the room. Only a few guilds managed to kill him before he was nerfed.
** Old Naxxramas deserves its title as the final and most difficult raid dungeon of classic [=WoW=]. It would be easier to list the bosses that are not ThatOneBoss, but some standouts are listed below.
*** Patchwerk is a gear check boss that requires perfect timing from the healers to avoid having the tanks die.
*** Gothik the Harvester is easy once you get to fight him. The trouble is the dozens of creatures he summons to attack you first.
*** Thaddius is pretty bad for groups that can't figure out how to move properly on his Polarity Shift, especially since each death makes it ''significantly'' harder to beat his berserk timer.
*** Heigan the Unclean has a unique mechanic requiring players to move across a floor in sync, chasing the "safe spot" amid lethal eruptions. The so-called "Heigan Dance" claims far more lives than the boss himself, who is notably easy. In particular, it's extremely sensitive to the latency of your connection to the game, meaning players who disconnect or lag behind others are pretty much doomed.
*** The Four Horsemen had the strictest timing and movement requirements of any boss before or since, needing as many as ''eight'' tanks to perform correctly. The few guilds that successfully defeated this encounter had no trouble at all with the remaining bosses.
* ''The Burning Crusade''
** 5-man dungeons
*** The ogre boss, Blackheart the Inciter, in Shadow Labyrinth. He casts a [[BrainwashedAndCrazy Mind Control]] spell on the entire group, forcing them to fight each other and using up all their resources.
**** This fight was especially notable in that it was the first fight with a Mind Control mechanic that affected the ''entire party'' instead of only one, meaning that for the full duration of the effect, your entire party is at the mercy of the game's sometimes ridiculous player-controlling AI (sometimes all the DPS will gang up on - and slaughter - the healer, sometimes you have casters using melee attacks on their own pets). The fight was notorious for punishing people for having good gear - as the best-geared members of your group would sometimes easily shred multiple lesser-geared party members.
*** Warbringer Omogg in Shattered Halls is a two-headed ogre that occasionally chooses to attack a random player other than the tank, and can't be taunted. Bring a bunch of cloth-wearers in there and prepare to get squished.
*** Kael'thas Sunstrider, in Magister's Terrace. Sure he is a DegradedBoss from his former status as the FinalBoss of Tempest Keep, but is still the hardest 5 man boss in Burning Crusade, due to the massive magical damage he inflicts.
** Karazhan
*** The Shade of Aran is an atypical boss in that he has no physical attacks by default, but casts devastating spells on random targets. This turns the fight into a movement and healing struggle that becomes absurdly more difficult when he summons elementals to protect him at 40% health. While all of his spells could be interrupted, locking out all three of his magic schools (Frost, Fire, Arcane) caused him to whip out his staff and unleash a devestatingly powerful melee attack (at the time around 10k, enough to one-shot almost anyone it hit). [[MemeticMutation I will not move when flame wreath is cast, or the raid blows up!]])
*** Netherspite (technically a BonusBoss, although this could be said of at least half the bosses in Karazhan), is of the "one stupid mistake can wipe the raid" variety. His mechanics require rotating players through a series of beams, a mistake with any one of which can result in the wrong person tanking or taking damage and completely wreck the plan.
** Serpentshrine Cavern
*** Lady Vashj has three phases -- the first and third are easy, but the second is a rush to defeat three separate types of adds: one that must be tanked, another that must be kited, and a third that has to be killed before it reaches and buffs her. A fourth type of add has a special MacGuffin that breaks her shield, but doesn't move, so the item has to be thrown from raid member to raid member, making the fight at times insanely frustrating.
**** While the later Sunwell Plateau raid proved to be the most difficult content ever to appear in WoW, Vashj herself was so extraordinarily complicated, with almost zero room for error, it remains the standard by which all Boss complexity has been compared to, at least in ThisTroper's guild. The above notation doesn't even scratch the complexity - during Phase 2, which is generally as far as most raids got, the 25-man raid was carrying out six separate tasks all at once, again with almost zero room for error.
** Tempest Keep
*** Kael'thas Sunstrider is a ''five'' phase boss that can last upwards of fifteen minutes. Assuming you survive his advisors, each of which is a miniboss in its own right, you then have to deal with his attacks, including MindControl, a Pyroblast that will instantly kill anyone it hits, and a phase where everyone is flung up into the air and must "swim" to avoid deadly floating orbs.
** Black Temple
*** Teron Gorefiend was of roughly average difficulty for the Black Temple when it was new, when level 70 was the maximum and people went into the Black Temple expecting a challenging raid. However, go in there at 80 and he ''becomes'' {{That One Boss}}. The Black Temple was designed for 25 players of level 70, but at level 80 everyone has much higher values in every stat, so a group of even 10 or 12 level 80s can steamroll through the place as long as at least a couple people know what they're doing. Teron Gorefiend, however, requires using new temporary abilities quickly, so if people go into Gorefiend's room without knowing the plan, they will wipe.
*** Reliquary of Souls is done in three phases, each of which has completely different mechanics. In one phase, you can't heal; in the next, you can't regenerate mana, and in the third, all damage you inflict is reflected back onto yourself.
** Sunwell Plateau is composed almost entirely of {{That One Boss}}es. Brutallus is a brutal gear check, M'uru combines the worst aspects of a {{Mooks}} fight and a damage race, and the Eredar Twins have very severe positioning requirements, to the point where they can severely challenge a level 80 raid that can otherwise clear the zone without a problem.
*** M'uru was as far as many, many raids ever got. That boss ate entire guilds whole. No less than six high-end guilds on ThisTroper's server alone crashed, burned and eventually split up and fucked off because of M'uru. And he wasn't even the final boss.
* ''The Wrath of the Lich King''
** 5-man dungeons
*** Ley-Guardian Eregos, in the Oculus, is a unique fight in that it's conducted while mounted on drakes, using their abilities instead of your own. Once the mechanics are understood, it's simple, but try getting a pick-up group to learn it.
*** Loken, in the Halls of Lightning, was at one point statistically the deadliest boss in the game, accounting for more player deaths than any other. The fact that one of his attacks forces to you remain as close to him as possible, while another requires you run away as fast as possible to avoid instant sparkly death, may account for this.
*** Argent Confessor Paletress in the Trial of the Champion 5-man dungeon summons a giant shadow creature that casts an area of effect fear spell. Constantly. However, a great portion of the dungeon's difficulty is due to the fact that players treat it as a standard 5-man dungeon despite it being substantially more difficult than anything that came previously.
*** Falric and Marwyn, the first two bosses in Halls of Reflection, are preceded by waves of {{Mook}}s that include a mix of ranged and melee enemies who wreak havoc with aggro management and healing. Wiping to any wave means you have to fight all of them again. The bosses themselves are no pushovers either: one fears constantly and uses a debuff that reduces damage and healing done by up to 90%; the other one has the ability to cut the tank's health in half, requiring intense healing to keep him alive. By comparison, the Escape from the Lich King sequence is trivial.
****.... No.
**** Try doing the Escape event with a bad tank then come back and say it's trivial.
**** The main issue is the DPS, as it's very likely that even if you can do enough damage to kill Falric and Marwyn, you still won't have enough to get through this encounter without the Lich King reaching your group and killing everyone.
*** Devourer of Souls in the Forge of Souls is another recent addition that can be a nasty surprise for players used to the relately easy launch dungeons. He has a hard hitting, fast spell that should be interupted as often as possible, hard to see area effects and several nasty special abilities that require the whole group to react accordingly. One of them almost always kills the player it aims for, but fortunately its usually only used once at low health.
*** Keristraza in The Nexus. The party must constantly jump to prevent her Intense Cold debuff from stacking too high, but one of her abilities roots people to the ground. This is also made more difficult by the fact that it is often the first dragon boss that many players who don't raid fight, meaning people need to learn how to avoid her Tail Swipe and breath attacks while DPSing, and the tank needs to turn those away from the rest of the party.
** Malygos, in the Eye of Eternity, is another boss with a vehicle mechanic - in his third phase the raid must coordinate flying together on drakes while stacking a damage debuff on him, soaking his WaveMotionGun style breath attack, and healing themselves. Most significantly, if you didn't get through the first two phases fast enough, or with enough raid members alive, you won't have enough time to kill him before he TurnsRed and annihilates you.
** Although the new Naxxramas in ''Wrath'' is much easier than the classic version, Thaddius remains difficult due to the need to have your raid members coordinate their movements to avoid shocking each other. One mistake can kill several people and critically lower the raid's damage to the point where you can't beat his berserk timer.
*** Heigan also retains his difficulty due to all the reasons mentioned previously; failing to execute the "dance" correctly will kill you no matter how well geared you are.
** The Ulduar raid dungeon is notably more difficult than previous ''Wrath'' content, and although its hard modes don't technically count (being {{Bonus Boss}}es), some of the normal encounters can be brutally challenging. Mimiron in particular is notable for having four stages, each of which features one-hit-kill mechanics that must be avoided or soaked, and the fourth of which is a combination of the prior three.
*** Algalon does not qualify for this list since he's a BonusBoss, but it's worth noting that he was specifically created to be ThatOneBoss as an answer to complaints that the game is too easy. One of the developers warned "He feeds on your tears" in the forums. It became Algalon's {{meme}} before Ulduar was even released.
**** A huge part of Algalon's difficulty also came from the fact that he was the first (and as of this writing, the only) boss with a time limit imposed on attempts - you got one hour per week. (Raids in WoW reset every Tuesday.) Unlike any other boss, Algalon is deliberately set up to deny you the ability to take your time, wiping repeatedly until you learn how to do him - you have 60 minutes every week and once the 60 minutes are up, that's it. Better luck next week.
** The Faction Champions encounter in the Trial of the Crusader raid dungeon is nasty for any group that isn't used to PlayerVersusPlayer combat. It consists of a randomly selected group of opposite faction characters who behave like [=PvP=] opponents: interrupting spells, using crowd control, and ganging up on individual raid members. The only way to beat them is to keep ''them'' crowd controlled while killing the healers, not as easy a task as it sounds.
*** The Beasts of Northrend require a considerable amount of cooperation from all the members, making it difficult for raids with many pick-up members to progress. The first opponent, Gormok the Impaler, throws Snowbolds onto people, which cause damage to players until the DPSers kill them. In the second encounter, Acidmaw hits players with a poison that paralyzes them (''before the debuff timer even expires''), unless they run over to the tank on Dreadscale who has Burning Bile. The third opponent, Icehowl, is simpler, but if the raid wipes on one of them, they have to start over, and it is very difficult to resurrect people between phases.
** Icecrown Citadel, being the final major raid dungeon of ''Wrath'', naturally has the most difficult encounters.
*** Lady Deathwhisper could have been considered this before her first phase was nerfed, as coordinating the killing of multiple waves of {{Mooks}}, some of which are immune to physical damage and some to magical, while dealing with her Mind Control ability, was tougher than even Blizzard intended.
*** Blood Queen Lana'Thel turns members of the raid into vampires. They get a damage buff, but soon have to bite someone within 10 seconds or get mind-controlled. Getting the damage output to beat her enrage timer involves working out an order of who should be bitten when, then ''finding'' the right person to bite before time's up. Losing one person to mind control almost inevitably means a wipe. With 25 people, this gets...interesting.
*** Professor Putricide remains the hardest wing boss thus far, with incredible raid coordination required to deal with all of his abilities, capped off with a severe time limit. Only five guilds managed to defeat him in Heroic mode prior to patch 3.3.3.
***Nowadays, we have Sindragosa. Just...Sindragosa. While the Lich King himself is harder-he's the Final Boss and wouldn't go on this list. But Sindragosa? Oh, god. A fight that is basically built around RNG. The first phase isn't...bad. She pulls the raid in and they need to run out before a big ice blast happens. But during the whole phase, your casters randomly get a debuff that builds up as they cast...which does a LOT of damage if it builds up too high, so they need to stop casting to let it wear off. Meanwhile, melee randomly get hit with a debuff that builds up the more they hit her, doing more damage the higher it gets; so they need to stop hitting her. Good luck if you are a fast hitting melee. She has an airphase that isn't too bad; it just involves two people getting hit with Ice Blocks(not too close to others or it will chain-on 25 this can be a bit hectic but compared to what's to come...)and then these iceblocks need to be hid behind or her frost bombs will damage you(read: Kill you on Heroic mode.) They also need to be killed before the people suffocate, but this is fairly trivial compared to phase 2. Phase 2 is a nightmare where she ice blocks people during the fight, and casts a stacking debuff on the raid that increases magic damage done each stack. The RNG of the melee cold damage and Unchained Magic(the magic debuff from phase 1) continues. Tanks need to get out of the way or their debuffs will stack to high to survive her breath, which needs tanks need to switch and people need to run behind iceblocks. Oh, the Iceblocks during this phase chaining typically means a wipe. Most can get through the first phase with the air phase, but this last phase can make it fall apart in seconds. Strict, strict coordination must be set to get the iceblocks close enough so the tanks can clear their debuffs, but the blocks aren't chained. All of this over the [[{{Understatement}} most god awful annoying voice ever]] screeching at you the entire time. On Heroic mode? Though there has been technically harder fights, this one could possibly be one of the most unfun fights of the game if the crowds are to be believed. [[YourMileageMayVary YMMV]], of course, but she bears a bit of mentioning here.
[[/folder]]

[[folder: Kingdom Hearts]]
* It's rather ironic that a series that's got complaints lodged at it for being easy has a ''lot'' of fans raging about difficult bosses...but nevertheless, even some hard games have sudden difficulty spikes.
* In ''KingdomHearts'', it's frequently a toss up between the second battle against Riku in Hollow Bastion, and the fight against Dragon Maleficent, which occur within minutes of each other. The first is like fighting yourself, except with absurdly fast and powerful attacks. The second wouldn't be too difficult, except that the boss's only weakpoint hovers out of your reach for most of the battle.
** I only managed to defeat Dragon Maleficent by waiting my party members to reduce her HP, while Sora stand from the distance avoiding her ranged attack (Thank goodness, she cannot run after Sora). When she (It can be a while with your party members getting KO'd constantly) finally have low enough HP for Sora to go ahead and defeat her, before she knock him out first.
**This Troper personally finds the Riku fight the hardest in the game, it took her ''weeks'' to defeat him, and the fight with Maleficent directly after? Beaten on the first try.
**This Troper actually finds Giant Ursula to be absurdly hard. Dragon Maleficent was ''cake'' next to that, and Riku only slightly tougher than the dragon.
***I agree, try her on hard/proud mode and tell me she is easy. The little thing that shoots beams from above does half your health, her bite does 3/4, the bubbles for 1/4 each, then she gets her beam spam ability and the fight ends up lasting forever and one screw up, you die, start over.
***Are you serious? Ursula is the easiest boss to me. She only targets sora and if you use Ariel and donald you almost never need to heal anyone. you dont even have to attack her. just swim all the way towards the camera and as far up as you can. only the sky lasers and maybe bubbles will hit you. all you really gotta do is heal when necessary (which donald and arial do anyways so maybe not) and attack her to speed up the battle since ariel and donald will be hitting her the entire time.
**I had my own crazy experience with the second show-down with Riku. When I first played the game, I just could ''not'' beat Riku, so much I stopped playing. When I started playing agin three years later (with a new save file) it took me forever to beat Ursula as well as the second Maleficent. But when I faced Riku the second time, I beat him within 2 minutes.
** The first time I played Kingdom Hearts, while I had a lot of trouble from all of the above mentioned bosses, The worst for me was Chernabog. I literally could not beat him the first time i went up against him, to the point that I stopped playing for nearly a year. Even after I went level grinding for a few hours, it was still tough. Then, the second time I went through the game, I went for a completely different strategy and had no problems at all. It made me wonder why Chernabog was That One Boss for me the first time.
* Organization XIII has a couple. Xaldin is frequently cited, despite being the only Org XIII battle where [[MercyMode Mickey can save you]] and the fact that Reflect abuse renders him almost helpless, especially against his ThatOneAttack. And then there's Demyx and his water clones...
** We mustn't forget the Vexen fights as Sora in ''Chain of Memories.'' Even if he doesn't break any combo you use with ubiquitous 0 cards, he'll probably end up simply avoiding all damage by blocking your attacks with his enormous frickin' shield!
*** This is worse in the Game Boy Advance version, in the remake it's a little easier to attack his vulnerable spots. (The Defenders are the ''hardest'' enemies in the Game Boy Advance version.)
**** What also makes the second Vexen fight harder in the GBA version is the small field, making you very vulnerable to that damn Ice Needles attack! You need a TON of 0 cards to get through that fight...
** Zexion can be pretty difficult if one doesn't know what they're doing or how to avoid the cards.
** Despite how Demyx appears to be the SpoonyBard slacker who really doesn't care about ''anything'' except playing sitar, you'd be surprised how many people think he's fits the description for ThatOneBoss. Sure, there's some FakeDifficulty in the form of LuckBasedMission in there, which most people don't like, but he ''certainly'' isn't one to be taken lightly.
*** Even without the ten-second part, Demyx is a beast. He has a multi-hit melee attack that he randomly uses, a special melee move that can be turned back on him with the Triangle Action Command (but the window is small and often you won't even notice him using it until the brief cutscene plays), and he goes absolutely ''berserk'' with his water attacks: water towers that erupt under you, water tower walls that advance toward you as Demyx walks toward you, machine-gun water orb blasts, rains of water orbs, a homing water tower explosion, and a water tower trail that erupts behind Demyx when he jumps towards you at lightning speed. Oh, and unless you land a strong hit or a chain of hits, when you get his health down to half he can't be flinched out of his attacks.
* Nearly every boss can kill you with 2 hits on Critical Mode in Kingdom Hearts II: Final Mix, even Pete can kill you until you lose your patience, Pete!
* In the original GBA game, but not the remake, Captain Hook is far more powerful than the other bosses at that point in the game, partly due to the GBA controls and his stunlock attacks.
** The field makes that fight in the GBA version even more difficult. As the ship keeps constantly tilting side-to-side, it easily puts you almost always on the receiving end of Hook's bombs.
* Marluxia's first form has several extremely fast attacks, partlicularly the one where the screen flashes and he executes a forward slash, and his Blossom Shower is nearly unavoidable, but thankfully doesn't hurt.
* Riku Replica. The [[spoiler:fourth]] time you fight him in Sora's half of the game, he's just plain ''hard.'' The second time you fight him as Riku is worse though, due to your fixed deck: you only have a one-use enemy card and unpredictably spawned Mickey cards to heal you!
**This Troper got all the way to Maleficent using the starting deck. Even after editing the Deck, he still never Card Broke anything intentionally. By the time he got to Riku Replica (Fourth time), it took this troper a year of ocasional play to defeat him, it doesn't help that right before him you have to mash through a very long cutscene. By the end of the battle, this troper had mastered the game and had a deck that tore through the last four bosses like a hot knife through butter. All from one battle!
* Leechgrave in ''358/2 Days''. It has a lot of HP for that point in the story, hits like a truck, and also requires taking out four ''regenerating'' tentacles before you can hurt it without nearly dying.
**That is unless you know that you can block the tentacles to stun them then use them as cover for the leechgraves poison bullets, if you take them out they stay out unless they are the fourth one in which case go after the main body.
* In ''BirthBySleep'', several bosses can be quite challenging. (the optional boss not included, being ''ridiculously'' hard)
** Maleficent Dragon once more can require several tries to do properly.
** [[spoiler: Braig. Just like Xigbar...and arguably harder with Aqua.]]
** Whenever you fight Vanitas with Aqua...ouch.
** Needless to say, expect entries about how hard some bosses in Aqua's campaign can be - she requires some practice to master.
[[/folder]]

[[folder:{{Tales Series}}]]
* The three dragons in the middle of ''TalesOfSymphonia'' right after Botta and Yuan do a ridiculous amount of damage, basically threatening to kill your entire party within 5 seconds. On top of that, it's almost impossible to stop them from interrupting your healer and mages so you'll have an almost impossible time using any of your powerful healing or magic spells. Finally, the camera system is so confusing you won't be able to keep track of where the damage is coming from. I personally think that that particular battle is the most difficult in the game, though Botta, Yuan, Kvar, and Magnius are all very hard. Interestingly enough, like most Tales battles, once you kill a single dragon the battle becomes a cakewalk.
** There's also [[spoiler: Alice and Decus]] from ''TalesOfSymphonia: Dawn of the New World''. It's essentially a 2-on-2 DuelBoss fight, them against Emil and Marta. What makes these guys so tough is that the latter constantly goes after Marta, making it nigh impossible for her to heal without Emil defending her... and if he does defend her, the former starts casting devastating spells or healing for astronomical amounts of HP at once. If you try to send Emil after the enemy spellcaster and just let Marta die, you'll find that said spellcaster is significantly harder to take down than Marta, and then Emil gets ganged up on and killed. If you try to control Marta, you get to experience just how stupid Emil's AI is. And as if all of that wasn't bad enough, there's also the fact that BOTH OF THEM CAN USE A MYSTIC ARTE. And they will. Frequently.
*** This is where [[{{Mons}} monsters you capture]] come in handy.
*** Another bad part. For some reason in this game, only bosses can use Overlimit, which keeps them from flinching when attacked. If Alice uses her healing artes while in Overlimit, and you can't perform a Mystic Arte, or even a Unison Attack, you're fucked.
*** And when you learn that Alice can, and will, revive Decus if you somehow managed to kill him first, it becomes downright suicidal to leave her alone.
*** Pfft. Forge an Echo Tracer (you can do it as soon as you get to Triet Ruins. Which is what, Chapter 3?) and Emil becomes an unstoppable god. And if you don't have that, you can always just save the Unison Gauge to use Marta's Mystic Arte, which heals you fully and does a nice chunk of damage.
* Fang Wolf from ''TalesOfPhantasia''. He uses repeated combo attacks that can instantly floor even the MeatShield.
** Undine from ''Tales of Phantasia''. She wouldn't have been so challenging if it wasn't for her wave attack. Her wave attack would run from right to left across the screen and would hit every one of your party members and had a very small charge time. The wave would hit for somewhere in between 600 and 700 damage to your entire party when, at that point in the game, you'll be lucky if anyone other than Cless has over 1300 HP. What really seals the deal for being absurd is that Undine ''is capable of spamming her wave attack''. If she starts spamming it, then there's nothing you can do to survive. It also doesn't help that she usually casts Delay on Cless so it becomes even harder for you to interrupt her.
* Many of the Summons in ''TalesOfEternia'' are like this, but Undine and Celsius stick out in particular. Undine casts "Spear of Baptism", a move that pierces across the entire battlefield. It has to charge for a couple of seconds, which would be great--except that Undine is also untouchable while charging, which neatly nixes any attack chain you have going. Celsius, meanwhile, is extremely agile, can inflict Freeze with a touch, likes to sidestep physical attacks, and will cast Blizzard, one of the most powerful Ice spells in the game, twice in rapid succession, which can easily kill an otherwise appropriately leveled party with no room for argument. Oh and let's not forget Sekundes who can cast Maxwell Extensions. Consecutively.
** Try fighting the bosses on hardcore. Let's see... Sylph's Cyclone is an instant kill, Efreet can chain cast Explosions and a Maxwell Extension resulting in death to anyone not with heavily stacked fire resistance, Celsius can now extend Ice Raid/Chi into Maximum Burst, which just flat out kills anyone it touches without two Flare Capes (and you want to rune bottle those Flare Capes to Aqua Capes for the fight, to protect against everything that isn't maximum burst), Volt can just pulls Indignation instantly whenever it wants, Maxwell instantly kills you with Maxwell Minimus, Valkyrie starts to use Valkyrie Protectors in rows (I've seen her do four in a row once) plus chaincast Ray at the end of each one, and the final boss cast Fear Flare multiple times in a row leaving you to be able to do nothing except heal with items -> run out of items -> die.
* ''TalesOfTheAbyss'': The ostensible FinalBoss that resides in [[TheVeryDefinitelyFinalDungeon the (supposedly) Very Definitely Final Dungeon]]: [[spoiler:"Master" Van]]. It was a [[ClimaxBoss climactic point]] in the story and was built up to be the final confrontation before the NotSoFastBucko, yes, but the battle is still far and away the most difficult you've had so far--none of the other bosses up to this point even came close. Over 100,000 HP, throwing out high-level Arcane Artes like breadcrumbs, and only the second boss so far to use [[LimitBreak a Mystic Arte]] that can, and ''will'', instantly kill anyone who's caught in the blast radius early enough in the attack. This troper actually had horrible flashbacks to [[BonusBoss Abyssion]] from ''TalesOfSymphonia'' upon finally reaching the victory screen.
** Worse than the aforementioned-ostensible-FinalBoss is the penultimate boss of the game: Sync, the last living [[QuirkyMinibossSquad God-General]]. For no adequately-explained reason, considering the fact that ''he's fourteen years old,'' this kid hits extremely fast, extremely hard, has a metric ton of HP, and can bust out ''two'' [[LimitBreak Mystic Artes]], a feat only elsewhere achieved by the real final boss, the {{Bonus Boss}}es, and the party themselves (but ''only'' in a NewGamePlus). [[spoiler:Then again, it would stand to reason that even a replica of a [[CrystalDragonJesus Fon Master]] would have exceedingly strong powers no matter how young he is. But he still seems disproportionately powerful when compared to the rest of the [[QuirkyMinibossSquad God-Generals]].]]
*** Telephone for you - it's Arietta. She actually ''does'' have two Mystic Ates, Big Bang and Evil Light. However, I will give you credit that she only uses one at a time when you encounter her, but I think she does use Evil Light and Big Bang during the same fight if you're on a higher difficulty - However I do remember getting Big Banged after she killed anise with Evil Light, but I don't know if I was on the regular difficulty or not.
* Kornerupine the mad scientist and Incarose-ILL from ''TalesOfHearts''. All that needs be said about Cornelpin is that, until names began catching on, he was known on virtually all MessageBoards, videos, and other American fan work as "that fat bastard with the spin attack". The latter is a retread of a previous HopelessBossFight with more defense, more combos, bigger spells, a Hi-Ougi, and in general roughly as much power relative to the player owing to sheer annoyingness. And you're supposed to win.
* ''TalesOfVesperia'' had Gattuso in the Ehmead Hills. Unlike the previous bosses, Gattuso is much higher level, has much more HP, more attack power, is much faster, and can poison you with its melee attacks. What makes this worse is that there is no way to fully refresh your health and energy before the fight nor can you buy items, meaning you have to fight Gattuso with whatever you happen to be carrying. To rub it in your face, immediately afterwards the party ''talks about how easy the fight was'', and the next boss is a freaking cakewalk. While it's not necessarily the hardest boss fight in the game, it just comes way too early for most players and gives them the real first taste of the boss brutality to come.
***As it so happens, this troper discovered that you can in fact leave Ehmead Hills at any time and go back to town to resupply on items and synthesize new weapons. It made his fifth attempt at battling Gattuso much easier.
****this troper actually broke out in tears when he saw Clint kill another Gattuso in ''one hit''
** The boss of Zaude as well as the final boss are at least ten times harder, for different reasons. The former has an unblockable move that can wipe out the party, and the latter just spams status effects.
*** If you do a certain sidequest, [[spoiler:[[PerfectRunFinalBoss the final boss]] ''[[OneWingedAngel gains an extra form]]'' that is several levels higher and that much more difficult. This form is, in fact, comparable to the Devil/Fell Arm {{Bonus Boss}}es from previous games in the series (same sidequest, in fact), making this a rather devilish fusion of FinalBoss and BonusBoss...]]
** Another incredibly difficult boss--although more due to circumstances--comes in the form of Captain Schwann. The main reason he's incredibly difficult is that your party is missing its two primary healers: Estelle [[spoiler:(who's [[DistressedDamsel being held captive]] by [[CompleteMonster Alexei]])]] and Raven [[spoiler:(who is ''the boss you're fighting'')]], and he will take full advantage of that fact to rip your party a new one with devastating strike artes and a hard-hitting [[LimitBreak Mystic Arte]] that's likely following the killer combo he just pulled on your party since he was in [[TurnsRed Over Limit]].
** Ooooooh man, what about, say, [[spoiler:Khroma dragon]]? This troper has a ''lot'' to say at her, that ''stupid'' tail attack she just pulls out of ''nowhere'', and when she flies...PAIN. IN. THE. ASS!!! It's a good thing he had Judith in that battle, she was a ''lifesaver'' against flying enemies.
** Alexei, because aside from being really strong, he would spam is Brilliant Cataclysm mystic arte, which literally pull out of ANYWHERE, even when you are comboing him, and being a mystic arte, it really hurts and you can't dodge it.
** Anyone who has gone through unknown mode will remember Zagi's Blastia Field on unknown. It rains red bombs and on unknown even at max level it does 5K each. 2 hits you die, and it covers the entire field making it undodgable. It is essentially luck whether you live or not. He is included in the optional dungeon you cannot save in and can spend hours going through before you get to the end. Nothing like running into him while in there and losing hours of work due to blastia field.
** Needless to say, it's pretty safe to assume TalesOfVesperia has some rather difficult bosses.
* ''TalesOfLegendia'' has Stingle. Crazy attack power, high HP, really long reach and (get this): he can enter stances that if you attack him, he'll counter-attack. This will hit everyone in range. ONE OF THESE IS AN INSTANT-DEATH SKILL. Which means that if you're not paying attention you can have three quarters of your party dead in an instant and not know why. Luckily the preceding boss drops an anti-One hit KO item, but if you didn't know this beforehand, you're dead. Shadow Chloe and bonus boss Mimi can kick your ass too, as well as the final boss in both halves, one due to a quick, high range knock-down and the ability to rapid-fire spells while invincible, and the other final final boss, who can pull off crazy combos and some nasty spells, and one good-range, fairly fast (if telegraphed) special that will leave your asshole in ruins.
** [[DualBoss Dark Senel and Dark Shirley]] deserve a few mentions. The former distracts you while the latter casts her un-dodgeable Blizzard spell, which can kill the entire party.
[[/folder]]

!!Other Games

** The fandom likes to joke that [[AnticlimaxBoss Kun Kun]] is one of these. It's a boss at lv100 with full boss embroidery around its name and immunity to magic. However, it only has 100 hp and, although its physical defense is very high and the fight will drag on, it will run away and do nothing else. That's it. It just keeps running from you. But it's still a running gag that Kun Kun is the absolute hardest boss in the game.
***Granted, for casters Kun Kun is very hard, because, you know, ''[[WallBanger we don't have any physical attacks at all.]]''

** Tanova in ''Baldur's Gate II'' was an unexpectedly difficult vampire mage in your first excursion to Bodhi's dungeon, with many deadly spells. Thankfully, she's not there the second time.

** Fadroh has a special move called [[ThatOneAttack Orb of Magical Offense]] that will boost his stats to insane levels, allowing him to destroy your party and turn an otherwise-unremarkable boss fight into a CurbStompBattle. The only way to prevent him from using this move is...[[LuckBasedMission by killing him before he does so. It is entirely random whether he will or not.]]
** The Holoholobird has prematurely ended many games for being a hard-hitting FlunkyBoss, whose flunkies can heal the main target for thousands of HP seemingly at will. Like the trio mentioned above, this also comes right after a disc swap that will trap you there without any way to train if you don't have another file on the first disc to reload from.
** Many people found themselves stuck on the boss right before the Heart-to-Heart scene, [[spoiler:Guillo]]. It has ''ridiculously'' strong stats, and is easily the most powerful enemy you'll face in the game (possibly even more than the final boss!). It can wipe out half of anyone's HP with a couple of normal physical attacks, and then KO them completely with a devastating finisher. It also has a finisher that will randomly hit the entire party, meaning one of two things: everyone will be brought down into the red zone, or you'll be left with one or two devastated characters. The worst part about the fight is, after beating it, it turns out to be (like practically every other boss up to this point) a HeadsIWinTailsYouLose situation; story-wise, the boss just knocks everyone out anyway, making you wonder why the developers didn't just go for the HopelessBossFight solution.

** Even when you finally realize that you can run away from the fight and save just afterwards (an inversion of numerous jRPG tropes), you still have to kill him to advance the plot; skipping the monologue doesn't seem to matter so much after the ''twentieth time...''
*** God help you if you brought Lynx ''and'' Harle to that fight!
** Garai in the Isle of Damned is pretty much this too.

** The worst [[strike:is]] can be the Golem boss, at least for first-time players. It reacts based on the attacks you use against it. Trying a physical attack will result in an attack that halves the attacker's HP, followed shortly by a second attack will almost assuredly finish the job (unless you healed the victim really fast). If struck by magic, it will copy the element and unleash an area-effect version back at you after a short charge time (enough for your characters to run through a single round). Needless to say, he can burn down your party very quickly, which is somewhat migitaged by the fact that it's treated like a HopelessBossFight. What's worse, later on, you encouter the Golem boss again, and now there's two of him... ENJOY! What keeps the Golem boss from being That One Boss to ''everyone'' is the fact that he has a crippling weakness which, when exploited by a savvy player, effectively makes him incapable of fighting back in either battle.

** ''DigimonWorldDS'' had a few, including [[spoiler: Zhuqiaomon]] and [[spoiler: Leviamon]].
* Macha in ''DotHack'' volume 4. She has an attack which charms the entire party without fail, meaning that all you can do is watch your team beat each other up and hope they snap out of it before you get a game over.
** Skeith in ''DotHack'' volume 1 is worse. Much worse. It has four attacks. First, its basic attack, which can bring a full health character down to near-death levels in one shot. '''It is capable of spamming this.''' Second, a wave attack, which is basically the same thing but hits multiple characters, specifically anyone who happens to be nearby (it can be dodged, but it's very tricky to do so, and [[ArtificialStupidity your allies never will]]). Third, Judgment, which hits your entire party, is ''impossible'' to dodge no matter what, and deals damage only slightly below that of the wave attack. And lastly, Data Drain, which inflicts ''every status effect in the game'', as well as causing damage that would be insignificant in a normal battle...but here, it means "kill range". Making matters worse is [[FakeDifficulty a nasty little shock]]: every boss battle up until this point becomes laughably easier in the second phase, as storywise the main character has drained their power, and gameplay has followed up until now. But here? Skeith becomes only slightly weaker, but becomes much faster. It then starts spamming its wave attack, killing characters so rapid-fire the time between uses of a Resurrect can be measured in seconds. "The Terror Of Death" ''indeed''. And [[strike:if]] when you die, you get to go through [[ThatOneLevel Chosen Hopeless Nothingness]] again, just to get back to Skeith. [[SarcasmMode Isn't that just wonderful?]]
** In most battles in this game, health restoratives are used sparingly, and revives practically never, if you're fighting intelligently. Against Skeith, you have to ''heal after every single attack'', or else the next one will kill you. Revives suddenly cease to be TooAwesomeToUse, but become essential to survival, because you are not always going to be fast enough with that health restore. And if you are unlucky enough to be hit with Judgement when all characters are below 75% health? ''You just lost.'' The worst part is that you cannot LevelGrind in order to make the battle easier: even at the game's {{Cap}}, all of the above applies. (Despite all this, Skeith somehow is also the most popular Phase by far; quite the EnsembleDarkhorse.)
*** After having to deal with this and being quite a few levels above the dungeon cap while STILL getting badly burned, I realized the trick. Skeith is kill-crazy. It doesn't matter who he does it to, just as long as he does it. So, I just let my party do all the work and let them take all the hurt. Totally worth it.

** The icewave attack makes the tension system useless, making it better just to heal and slash. And every boss post-Dhoulmagus (except [[spoiler:Gemon]]) has it!
* The Queen Bee in ''E.V.O: Search For Eden'', for being a flying tank, essentially, with an uncharacteristically erratic flight pattern. Also, the [[MamaBear Mother Yeti]], for doing heaps of damage and causing knockback.
** The Queen Bee isn't overly hard if you jump high enough. Later in the game, it shows up as a fodder enemy and needless to say, you're stronger by that point...
** The mother yeti is comically easy if you are (or can become) a bird, then you just goad her into jumping in the air after you and bite her. Otherwise...
** The Yeti in the next stage is a real bastard, too.
* ''LegendOfLegaia'' had the Berserker. A monster so powerful that it will give you nightmares--a hideous giant green mantis driven to the brink of insanity and over by the corrupting power of the Mist, it lurchs about with ridiculously powerful strikes and gives you the previously unseen status effect, Rot, which blanks out random attack commands.
** More of a PuzzleBoss though, since all you have to do is cast [[spoiler:Berserk]] on him and it's an instant win.
** The battles against [[spoiler:Gaza]] later in the game were also insanely hard. The second fight was especially hard if he abused his attack-all move, Neo Star Slash, which did over 1,000 HP each time. Underleveled players will likely see FragileSpeedster Noa going down in one hit every time from this move.

* Dugog from ''PuzzleQuest: Challenge Of The Warlords''. He's the first storyline boss you face, has a weapon that randomly does +12 extra damage, gets an extra turn every time he gains gold, and sports the Double Roar spell which is capable of killing you instantly. And at this point in the game, you probably won't have the stats or equipment to beat Dugog on anything other than luck or serious LevelGrinding.
** Dugog is far better classified as a WakeUpCallBoss.
* ''SagaFrontier'''s Green Sage, featured in Asellus' quest. Wouldn't be so tough if you had time to prepare, but the boss can come at any time, without warning, ready or not. Some players suddenly found themselves in an {{Unwinnable}} situation after saving at a low level and, no longer being able to leave to do any LevelGrinding without fighting the boss, were forced to start over from the beginning
** Technically, as long as you do not talk to a certain NPC in Shrike [[EventFlag you will not fight the sages]] giving you plenty of time to level grind or recruit allies.

** The Fire Gygas right after Spikey Tiger is this too for a player who hasn't learned to magic spam. All gygas's count if you don't use magic. They very frequently change into an unhittable vapor, often magic spamming ''the player'' instead.
** Magic is so overpowered in ''Secret Of Mana'' that one of the hardest bosses in the game was the vampire, purely becasue the mechanics of the fight made spamming his magical weakness difficult. This guy can kill a full HP party member with a single spell, sometimes 2 members if you are a bit underlevelled.
*** If the player maxes out Sylphid and uses Air Slash, it actually works well. In fact for damage/magic, the 2MP spells tend to work really well.
** Boreal Face, the souped up PaletteSwap of Tropicallo, has an enormously high magic defense. Up until this point the player was probably relying on magic for quick boss fights. Boreal Face actually will still have more than ''half'' its HP left by the time you unloaded Popi's MP (included using Faerie Walnuts). Although that makes Boreal Face a WakeUpCallBoss.
** The Snap Dragon has the ability to eat players, which not only almost certainly kills them, but restores its health in the process. To make matters worse, if you don't walk out the front door of the Grand Palace and save, you will end up doing it all over again if you lose.

*** [[GameBreaker Duran, Kevin, Angela. Aura Wave, Deathspell, Eruption. Aura Wave, Deathspell, Eruption. Poto Oil. Aura Wave, Deathspell, Eruption.]]

*** That path also gets to fight Deathjester, his MonsterClown [[TheDragon dragon]]. At the start of the fight, he splits off two invincible copies, forcing you to guess which one can actually be hurt. Even when you do find the one you can damage, you have to hope that the game's auto-target system for physical attacks figures out which one you're going fo. While you do that, he's casting all sorts of nasty spells to hit you with debilitating status effects like Snowman and Mute, which at the worst will completely incapacitate one of your characters, and he's ''always'' casting. Oh, and did we forget to mention his instant-death spell? The one he likes to use three times in a row?

** The Phantom Soldiers on your second visit to the first planet are an awful test of endurance. You fight eight waves in a row with no break and, maybe it was just me, it feels like it's pretty hard to do any solid damage to them, but they can certainly hurt you. I hope you brought Sarah and someone to back-up heal, as long as being prepared to emergency heal with Edge.
*** And after the fight, just to throw salt into the wound, [[GodModeSue Crowe]] shows up afterwards and [[CurbStompBattle curb stomps]] them ''and'' their ship.

** With Master Kaen probably being a close second. Fortunately, it is possible to play an entire game without meeting either of them.
*** Unless you're a Monk, in which case you have to meet Kaen. He has the highest base damage in the game, the Eyes of the Overworld which give him immunity from wands of death, and he ignores [[spoiler:Elbereth]], which can be used to hold off most other enemies. Making it all the worse is that these strengths are especially dangerous to Monks, who are the only ones who have to deal with him anyway.

** Bundt's health is actually measured by the candles on its "head". What makes the boss so difficult is that you have to attack it until all the candles are blown out, and you can only blow out one candle per character. Meanwhile, Bundt is restoring one candle per attack, and it can attack twice per turn, and is pounding you with powerful all-hitting magic spells. So you have to pray that all three of your characters stay alive long enough to finish the thing off, and then you still have to deal with Raspberry, who has all of Bundt's attacks.
** If you haven't leveled up enough during the first part, Croco can ''really'' drive you mad, especially since he can heal himself. And he's the ''second mini-boss in the game'', not counting Bowser.
** The Axem Rangers are plenty tough, considering there are [[FiveBadBand five of them]], and each one has a different variety of attacks, including [[DarkChick Axem Pink's]] number of [[TheMedic healing spells]]; not [[ShoottheMedicFirst attacking her first]] is insanity. And even after beating all of them, [[SequentialBoss they "combine"]] with their Zord/warship thing for one more go, using the insanely powerful [[WaveMotionGun Breaker Beam]] attack, which will lay waste to all members of your party not wearing the [[GameBreaker Lazy Shell]], though fortunately it takes a turn to recharge before firing again. After the Czar Dragon and these guys, you DESERVE that damn Star Piece.
*** And what else do you get for that effort? A measly 17 experience points and no coins. Far weaker foes offer more.
*** If you think the Axem Raners are hard in their non-gamebreaker state, you should have tried facing them in earlier versions of the game. Either due to a bug or something else, the individual Axem Rangers could continue attacking even when they were defeated. This only stopped once all five were defeated and the red guy started firing the beam.

**And chances are that you sold the Insect Crush as well, thinking you might not need it anymore. Oops.
** Amon in ''Lufia: The Legend Returns'' is ''incredibly'' difficult due to the battle mechanics of the game. You have nine characters at a time in battle, and you can only act with three of them. Amon has a confusion attack that hits all nine of your characters, and confused characters can always attack. If you're unlucky, you can end up with eight confused characters attacking (and slaughtering) your lone non-confused character. There is an equippable item that will protect from confusion, but there are only three of them in the game...
** If you think you can have it easy by depleting Amon magic points, expect to see a lot more of Galactic Lancer, [[NumberOfTheBeast which deals 666 damage]].
* The ''MonsterRancher'' series doesn't really have ''bosses'' per se (Well, ''Monster Rancher EVO'' did, but that's... [[UnexpectedGameplayChange well...]]), but it does have tons of computer-defined opponents--some of whom could easily be ThatOneBoss, despite actually being "That One Monster." There are too many throughout the series to list all of them, but there are a couple patterns:
** In the first game and if you lack speed. Golems, There was one in every grade (E was avoidable, every other grade was not) Had enough power to KO your monster in one hit possibly killing it afterwards, and worst of all many of the times you have to beat the said golem to win the tournament.
** ''Monster Rancher 2'' had a species of monster known as a Gaboo. These had extremely high life and ridiculous attack. As you may have expected, they're absurdly hard to defeat, and some of their attacks can actually ''KO your monster in one hit.''

** From the sequel, ''VampireTheMasqueradeBloodlines'': the two endgame bosses. Depending on who you side with, you have to defeat one or both of them. The first is Ming Xiao, who starts off with a NightmareFuel-riffic transformation into her [[OneWingedAngel final form]], a giant tentacular [[TheBlob blob of goo]] that can spawn copies of itself, on which superpowered attacks are next to useless; you're basically screwed if you don't have a high Firearms skill and the flamethrower, and even then if it wasn't for the game letting you save during a fight, an unfortunately-timed spawning can destroy you. The second is the Sheriff, who also transforms into the [[GiantFlyer Chiroptean Behemoth]]; again, you need some crazy firearm skills and the sniper rifle to take him out, and it's a long, long slog.
*** Also from ''Bloodlines'', Bishop Vick. He's super fast and has a shotgun with unlimited ammo. If you decide to turtle, you'll either get ganked by his army of zombies, or Vick will just superspeed next to you and kill you in half a second. He's also a vampire, which means that he's extremely resistant to bullets himself. To make things fair, you can hit him while he reloads, but even if he doesn't complete the animation he receives a full six shells (although it seems like more) to destroy you with. Unless your character is completely combat oriented (which the game actively discourages), your only hope is to pray that the AI bugs and Vick gets caught in a loop. Unlike Ming Xiao, he's optional, but beating him is required to complete a long sidequest chain and get an extremely helpful item, so he probably counts.
*** ''Also'' from ''Bloodlines'', Wereshark. Deals massive aggravated damage with every punch even with high-level fortitude, can take a serious beating... oh, and you have to kill him without him killing Yukie. Odds are if you try and deal with him with a gun he'll maul her... and you'll hit her too. Good luck if you're a clan without Celerity. Damn near impossible as a Ventrue (Presence doesn't affect him, but does hinder Yukie, and Fortitude might as well not be on).

** Lenus is a lot easier the second time you fight her. This is when she [[spoiler:is in Dragoon form and is backed up by a dragon]]. The mind boggles.

** See also: that goddamn giant bird.

** Never mind the second time around, where you're not even supposed to win and can't properly fight him except as a BonusBoss.
*** You can win that one using Velocity Crash pins (especially Wolf), and keep watching Beat carefully.
** Forget Minamimoto, that GODDAMNED ELEPHANT is death.
** Ya, Minamoto is fricking easy, THAT DARN ELEPHANT IS CHEAP!!!
** Uzuki and Kariya, at least if you try and fight them on Hard or above. That five-star attack will ''haunt my dreams.''
*** Uzuki by ''herself'' is a nightmare, even when she's not teamed up with Kariya. She's got multiple BulletHell esque energy shot patterns, but the real problem with the fight is how she switches screens with her shadow self. When she does it, it has the effect of her {{Flash Step}}ping and breaking your comboes, even if she goes ''exactly'' where her shadow was on the other screen. How often does she do this? Let's just say that, on Hard, she makes ''Minamimoto'' look "zetta slow". It's ''really'' hard to pass that light puck when she doesn't allow Beat to land more than 2 hits of his (5-6 hit) combo.
** Kitaniji and [[spoiler:SHIKI]]. [[spoiler: Shiki]] gets a massive power boost out of nowhere since [[spoiler: she was in your party]] and Kitaniji can FREEZE TIME to try and hit you, and that's just on normal!! On hard Kitaniji gains 2 Bullet Hell-esque energy blast attacks, and loves comboing them with his time stop move for maximum pain...
*** He may not count though, being the [[SequentialBoss first stage]] of the final boss.

** Not only do you have to beat on the minions until they turn into control panels, you must make sure they turn into control panels on the designated spots. If not, they turn back into minions. While you're doing this, you must also contend with Mikhail's laser attack, which is circling around the arena. As you progress, he will add a ''second'' laser for more jumping "fun".

** Also, Joachim's teacher in Covenant when you first meet him. What makes this battle so hard? Well, he'll be using Grand Slam ''all the goddamn time'', which wouldn't be so bad if it wouldn't ''randomly kill you instantly''. And you only have Joachim for the fight. [[SarcasmMode Yay]].

** The worse example, however, is The Bonerdagon, the boss of the Level 7 quest. Apart from the [[BigBad Naughty Sorceress]], it is the only monster capable of blocking skills and item use. Considering that it takes a rather substantial boost to one's stats to stand toe-to-toe against it compared to rest of the quest itself, it can prove to be very very frustrating. Unlike Baron von Ratsworth, however, one can just level-grind to take it on, but it can be a pretty severe bottleneck.
** And speaking of the Naughty Sorceress, she herself was easily ThatOneBoss back in the day. Like Baron von Ratsworth, she scaled to your stats, meaning she was tough no matter what, and like mentioned above, she could block skill and item use, PLUS she dispels all your buffs right at the start of the fight, constantly healed herself, and shrugged off your de-leveling effects. And did I mention she was impossible to beat if you weren't equipped with a specific weapon, which has a mere 30 attack points? With the introduction of NS13 though, she's much easier, as her stats are set around 200 and no longer requires the aforementioned weapon to beat (though it DOES have to be in your inventory).
*** She is still, however, STUPIDLY hard as a mysticality class, whose only real way to do any meaningful damage is skills. What does the Naughty Sorceress block with annoying frequency? Yep.
* Duriel of ''{{Diablo}} II'', despite being only the mid-game boss, is probably among the most dangerous of them and easily the most frustrating. For some reason, the designers thought it would be great to pit the player against an enormously fast boss, with an aura that irresistably slows the player, in a bare room perhaps eight times his area. This in a game where hit-and-run is god; half the classes are explicitly designed for ranged combat only; and even the "tanky" Paladin isn't expected to last very long in toe-to-toe combat. Against minions, that is; he doesn't last at ''all'' against a boss. On top of everything else, you can't escape the room to catch your breath, even though you enter the room through a big hole in the wall.
** Also, (at least originally) they didn't bother to have the resources for the room pre-loaded. You are basically teleported in there, so often you would have taken a few hits before it has loaded, or in multiplayer you may be dead by the time it loads. This made Hardcore players (where you can only die once) into ''very sad pandas'', [[RantInducingSlight to say the least]].
** Diablo himself is a gigantic pain in the posterior area, requiring the use of about a hundred town portals before finally succumbing to electric death on his latest character. Even ''Baal'' was easier. After playing some more on that same character, ''Nightmare'' Diablo was easier. Huh.
*** Duriel can be extremely difficult if playing online in a suitably laggy environment, where the loading lag you get from teleporting into his chamber can kill you before you get time to drop a town portal so it'd be easy to get back to your corpse. Less common nowadays, but at the time when ''Diablo II'' was released, 56k was as good a connection as you'd normally get so Duriel racked up a significant bodycount.
** The three Barbarian Ancients are pretty much the hardest encounter in the game--topping Duriel, Baal, and even Diablo himself (who at least gave you ample room to hit and run). The first time I found them with my Assassin, I got utterly gimped. And then on Nightmare, I had to backtrack and powerlevel something in the vicinity of nine levels to have a ''chance''.
** I disagree, Duriel was consistently harder.
*** What made the Barbarian Ancients so damned difficult was that using Town Portal to escape would heal them back to full health, meaning yes, you had to kill them all in one go. This Necromancer troper brought in an ''army'' of revived minions, skeleton magi, and a Fire Golem... and it was still a pretty close fight. And yeah, he curbstomped Nightmare Baal later.
** The councillers in Act III on higher difficulty modes. They're just superuniques, but on higher difficulties they gain a lot of traits, and sometimes those traits work TOGETHER to create a new definition of pain. Can you imagine Conviction plus Might plus Cursed plus Extra Strong plus Lightning Enchanted together?
*** You forgot Multi-Shot.
*** The thought of this will cause nightmares, and is a strategy used by ''players'' to curbstomp the game. Each of the effects gives something to double your damage....and they stack. All in all that'll quintiple the boss's damage...and every time you touch one it spits out a field of lightning that hit hard enough to start....

** The fact that he inhabits [[ScrappyLevel one of the most annoying]] AbusrdlySpaciousSewers ever doesn't help.
** Id is a pain to fight each time you face him since he can do massive damage to any character in a short amount of time.
** The second disc really pushes this to the max and can piss off many a people. One of the first fights that you have in the second disc against the Sufal Mass and Sufall. You can't do elemental attacks against him or it will heal him. If he happens to [[spoiler:kill the last Sufal he will unleash a massive attack against your party]].
** The Elements also are quite a pain to fight. What makes it hard for them is that one of them can heal the other party members. Plus if you use the wrong elemental attack against them it will heal with. Don't even think about attacking Domimina until you beat everyone else or she will heal her self regardless of what you to do attack her.
** [[spoiler:Hammer]] is another that one boss. He's actually fairly easy to beat, but when his HP gets low enough he will [[spoiler:start to [[TurnsRed glow red]] and will blow up, killing everyone unless you either defeat him before he blows up or run away. Running away however will prevent you from getting a rare and awesome item.]]
** The first fight against Deus is a pain the ass since he starts out with one attack that all he will do is cut EVERYBODY's HP in half including himself. If you attack before a certain point which is when he [[spoiler:lumps over]] he heals himself for a huge amount of HP. On top of all this, the game has a habit of ''crashing'' during this battle.
** The last Ramsus and Miang boss fights also fit in that one boss as well. With Ramsus he has an attack that will lower all active teams mates to 1 HP. If everybody on he team has more than 1 HP, he will do the attack again later on in the fight. The main problem is that you have to heal yourself and fight him at the same time while keeping an eye on your fuel. Miang is worse since [[spoiler:she will mirror the damage done to her back onto you.]] However if you just [[spoiler:charge]] instead of [[spoiler:attack]] her attack will do nothing and you can have a chance to fully recover your HP.
** To add insult to injury, many of these guys have a lengthy {{Cut Scene}} to slog through beforehand.

** ''Nightfall'' has Shiro Tagachi. The amazing thing is that he was the BigBad of ''Factions'', and he wasn't nearly as hard there, despite the fact that he had two incredibly annoying and powerful skills in ''Factions'' that he doesn't have in ''Nightfall''. (On the other hand, in ''Factions'', the mission to fight him consists entirely of "Defeat Shiro." In ''Nightfall'', you have a fairly lengthy and difficult mission to get through before Shiro.)
*** Your mileage may vary. This troper found Imperial Sanctum far more difficult than Gate of Madness. Mostly because in Gate of Madness, you get to fight Shiro with a massive set of buffs, and can take a full party with no fear of banishment. Shiro generally dies extremely easily in Gate of Madness--not so in Imperial Sanctum.
** And while we're at it, just about every elite mission. Due to henchmen being disabled and heroes limited, if you don't have a player group you're completely SOL and JWF.
** Coventina the Matron... or any of the other Mursaat Monk Bosses from ''Prophecies''. It takes a specialised -team- to take them down effectively due to the efficiency of their self-healing... and can consume a LOT of time. Makes for much trouble if coupled with OTHER Mursaat bosses.
** Elementalist bosses in general. All bosses and boss-like foes have an inherent double damage bonus (on top of the bonuses they get for their level), meaning some of them can pretty much wipe a party in seconds.
**Then there is Dhuum, of the UnderWorld, this boss is now a MANDITORY fight to complete the UnderWorld where before you just had to finish the quests. Those quests? You still need to do them all first before he appears and there is no second chance, if you all die that's it, you got to do it ALL AGAIN. Dhuum ranks up there with Kanaxai and Urgoz...
***You're giving Kanaxai and Urgoz far too much credit.

** Silly person, it's quite obvious why he doesn't heal. [[CaptainObvious Robots don't have stomaches!]]
** Ness's Nightmare from the same game is a ''huge'' pain in the ass to deal with -- first, because you're forced to go at it alone (unless you're lucky enough to keep a Flying Man alive up to that point, which is hard enough in itself;) and second, because it tends to constantly use Lifeup and power shields on itself before whaling on you with high-level PSI attacks. It ''is'' possible to at least grab a special pendant that nullifies the effect of its "glorious light" attack, but waiting for it to completely drain its PP so it can be rendered useless is a big hassle. (The power boost received at the end is a sweet consolation prize, though.)
*** Unless you know [[GuideDangIt the trick]]. If you use the normally useless Auto Fight option, you'll always win, because the AI can heal itself [[TheComputerIsACheatingBastard instantly]] instead of having to go through a menu.
** The Kraken is capable of being this way for some. While his HP isn't high he can deal damage that is likely to kill Paula and Jeff and WILL kill Poo unless you leveled him. The way around this is [[spoiler: keep the Franklin badge in someone's inventory, preferably with Ness. His thunder-like attack will reflect off of it and damage him]]
*** Of course, you could go through the Fourside Sewers and Pink Cloud to get Poo to a higher level,(You'll have to do it eventually) but he'll have the same problem there as well. As least you'll get a piece of his armor set.

** The Barrier Trio, later in the game, are also a pain. They're a group of three stone-like guardians, and they're resistant to most PSI attacks... and they cast tons of PSI attacks of their own. Once you're near to defeating them, [[TurnsRed they up the ante]] and throw the all-powerful PSI Starstorm at you. Then [[spoiler: they'll use it AGAIN, though it won't work]] [[CrowningMusicOfAwesome The music]] made up for it, though...
** I have difficulty beating the first encounter of the Masked Man (who everyone should know is really [[spoiler:Claus]]). You have to fight him after going through tougher Pork Troopers and he can consecutively attack, destroy your shields, and use PK Love Gamma which can really fuck you up. Not to mention his standard attack does 80 damage, his secondary 50, and his "lightning attack" will hurt everyone with about 100 damage except the guy holding the Franklin Badge.
*** BTW, only Lucas can hold the Franklin Badge and you can't give it to anyone else because it's a key item.
*** Plus, at this point, there is no way to heal before going into the two-part battle (except for dying) You have to make do with whatever you've got left after struggling through the area. (rare for this game, as bosses tend to be tough enough at full strength)
** New Fassad utterly decimates a good portion of players on their first time through, probably because his attacks hit everybody at once, and he can barrage you with status effects: fleas and forgetfulness (causing your characters to forget special techniques), paralaysis, crying (making your two physical attackers miss most of the time), etc. And just when you think you're making a considerable hole in his HP...''Fassad ate a Miracle Banana!'' and he gets back about 500 health points. He's sort of like the Clumsy Robot to players who are just picking up on the series, but sadly, his healing is no fakeout. Oddly enough, his second form (Miracle Fassad), encountered towards the end of the game, is considered much easier even though he possesses PSI Starstorm.
***Try fighting New Fassad at Level 30 and then talk about pain.
***Are you crazy? Miracle Fassad is much worse. He's even more fond of status effects, and has moves like PSI Freeze Omega, which do obscene damage, affect everyone, ''and'' can prevent a character from attacking. He also has some 5000 HP, and can use Luxury Bananas ON TOP OF an attack, so you'll get scenes like Fassad used PK Starstorm >> Fassad ate a Luxury Banana >> Fassad restored 587 HP!
**** Did anyone not consider LevelGrinding at that point, as many of the enemies in the sewers give out gobs of EXP and there is a healing spring nearby? Not to mention you can probably lay waste to enemies using PK alone, just do not use healing items before fighting Miracle Fassad, either that or do not [[spoiler: [[EventFlag speak to Leder!]]]] There are plenty of healing items sold in the city that can save your ass. Also saving up [[spoiler:the Magypsies' mementos is a boon for that battle if you really do suck at it.]]
** Mr. Passion sent everything but the kitchen sink flying! Duster took mortal damage! Duster got hurt and collapsed... [[RayAyanami This troper]] {{facepalm}}ed!
*** That's why you use your thief tools.
*** To be more specific, the one that makes enemies cry (His name is Mr. Passion after all).
** The Pork Tank is bad enough on regular difficulty, with the nearly useless Salsa, the SquishyWizard Kumatora, and the powerful but uncontrollable Wess fighting it. It has a powerful cannon that takes off 40 HP a shot even if you decrease its offense (both characters have about 100 HP at this point), an attack that damages both Kumatora and Salsa, and an attack that makes both your characters cry. On Hard Mode, where the HP of all enemies is doubled, it becomes an unholy killing machine with 3400+ HP. Here, it's a guarantee that Kumatora will run out of PP less than halfway through the fight. It really comes down to Wess being useful with his attacks, which he usually isn't.

** Commander Cherenkov's Gnosis form in ''{{Xenosaga}} 1'' qualifies, also. Not only is it him (in a surprise battle, nonetheless), but he also gets two pain-in-the-rear minions with an area-of-effect attack.
**No mention of Orgulla from Episode II? She was a nightmare that did terrible damage, including poisoning party members, and acquired boost at a ridiculous rate, which gave her the ability to kill your entire party in a short amount of time. The only real strategy against her was attack, heal, and pray.
**For ThisTroper, it was the Patriarch Sergius fight at the end of Episode II. Sure, his first form is pretty easy, but his second form is tons harder. He has a habit of boosting multiple times to cast an Ether attack on the same person (the damage gets higher for each successful Ether attack of the same element) including one a version where he first knocks you down and then casting another for maximum damage, but you can't boost over enemies so you just hope your characters evade or you have enough heals ready. He also can cummmon a machine by the name of Proto Omega to do massive damage in one attack as well, which can be combined with an attack from the Patriarch that can send your characters in the air. And this is just a few examples. If you're below level 40 then god help you, but even if you're above that, it becomes an exercise of you healing and him doing more damage at some points.

* ''LegendOfMana'' tries to avoid making baddies too difficult; either placing new lands close to home, or [[GameBreaker learning blacksmithing]] will let you through nearly everything. If you don't, though, it can get very ugly. Irwin essentially spams an area of effect power that fills the entire screen. The dragons hit a bit too hard to be fair. But the worst is the Sierra and Vadise fight. Large area of effect powers, some of which cause the player to fall asleep, nasty amounts of health, and you can only bring one ally where you'd normally get two. Even better, they [[IGotBetter get back up]] if you don't beat them both at the same time.
** On No Future, the highest difficulty level, Labanne/Tropicallo(they're recoloured versions of the same boss) is pretty ridiculous. You can only damage it by destroying two flowers which respawn at a set rate, and with the difficulty turned up it has a HUGE lifebar, so the fight will take ages no matter how you play. Worse, one of these flowers has a self-destruct with a large range -- one corner is usually safe, but if you're unlucky the flower can get slightly out of position and blast you anyway. And on this difficulty, of course, the explosion is a one-hit kill on just about anything, even from 999 HP. If you get through all that, there's the other one to deal with later in the game!
** Hell, let's be honest; even Tropicallo on ''normal'' qualifies for ThatOneBoss. [[BloodNightmaster This troper]] thought the game was a ''breeze'' (albeit enjoyable) until she got to him.
* Demon Droguza from ''ArcTheLadTwilightOfTheSpirits''. Just... Demon Droguza.
** Let's put this in perspective. Droguza is TheRival to one of the game's two heroes, whom you've fought three times before. Demon Droguza is when TheEmpire decides to power him up with the MineralMacGuffin Great Spirit Stones and turn him into an immobile, [[BodyHorror horrifically mutated]] monstrosity. With physical attack power that's through the roof. Think that's not so bad? He's got ranged attacks as well - a sweeping tail laser that slices across the midpoint of the battlefield (where you ''will'' be caught, unavoidably) and a giant energy ball that goes boom on your little cluster of fighters and nukes roughly half of their HP on a normal, non-grindfest playthrough. And your healer will very likely die. Add in the fact that the ressurection spells aren't likely going to be available to you at this point....

** Nightmare Orjugan (CombatTentacles that can OneHitKill, a WaveMotionGun blast that makes it harder to avoid said tentacles, and {{Doppelganger}} Mooks) and Nightmare Napishtim's first form (FrickinLaserBeams that take off half your health) were also ThatOneBoss.

* The Huff 'N Puff fight fom ''PaperMario''. Huff 'N Puff was a giant cloud, and pretty much every time you hurt him with your jump or hammer, tiny little cloud baddies would pop out of him. If you didn't get rid of the tiny clouds by his next turn, he would swallow them up and heal himself. Often there were six or seven tiny clouds that couldn't all be removed by the next turn. Also, he had a devastating electric attack, and often charged himself up so it would shock you if you jumped on him. Truly one of the more irritating bosses in the game. Don't get this troper started on the boss of the Crystal Palace.
*** Huff 'N Puff was pretty simple if you could get the action commands right with Sushie's Tidal Wave and Mario's Multibounce and Star Shower. Other area attacks and items were also capable of wiping out his minions, and would give the old windbag a beating, too. He can also only sustain eight (ten?) puffs at a time, so filling his ring and pounding on him ''hard'' with multi-hit attacks also made him a piece of cake.
*** Keeping the number of clouds maximized, though, risks Huff N' Puff using an "earthquake" attack that hits just as hard as his thunder strike.
*** The obvious way to deal with this was Lakilester's Spiny Surge. 2 aerial non-contact damage to all takes out the small puffs. Lakilester also takes out the Crystal King's doubles.
*** You nullify the damage done by the Tuff Puffs if you use the Chill Out star power, which works every Tuff Puff spawned until it wears off.
** There's also the Anti Guy fight. This guy has no gimmicks, he just hits HARD. As in 9-11 damage every turn (and that's when you get the ActionCommands ''right''). The average player will have about 30 HP around the time they face him, compared to his '''50''' (and your basic attacks deal approximately 4 damage a hit at this point). Thankfully he is entirely skippable.
*** If you answer a question wrong at a talking door in Bowser's castle, you will have to fight THREE Anti-Guys.
** The Crystal King is no slouch. He doesn't really rely on one gimmick, either; he can heal, he can split into copies, and his attacks really hurt (one can even freeze, taking Mario out for 2 turns at a time). He's no Huff 'N Puff, to be sure, but he's no joke.
*** Oh, this troper found the Crystal King to be much worse than Huff N' Puff. At least with Huff, he only healed around as much damage as you did in a round. The Crystal King a.) Has defense and b.) Can heal 20 damage instantaneously. And keep in mind, with that defense, you're usually only doing about 3 damage a pop to him. So, compared to Huff n' Puff's "Hah! There goes last turn's progress!" Crystal King just sits there hammering you, and then "Oh, by the way? The last three turns worth of damage? Yeah, didn't happen." And the first time I fought him, he literally spammed the hell out of that healing move. God I was so pissed.
*** there is on odd trick that you can abuse to make the crystal king easier: listen to the music. if you have the badge that allows you to hop on one enemy many times equiped, than you can listen to the beat of the song, and use it as a cue of when to hit the button.
** ''The Thousand Year Door'' has got the Bowser and Kammy fight, which if you are not fortunate enough to either a) have leveled up after beating Sir Grodus, b) packed a ton of items for, or c) be using one of the strategies that turns Mario into a Glass Cannon can be ridiculous. Basically you have to go through Grodus--a normally tough fight on his own--followed immediately after--with no gameplay break and therefore no chance to heal or save--by Bowser and Kammy, who can each hit hard and thanks to Kammy's presence heal. The game is at least kind enough to let you heal before sending you directly to the Shadow Queen and it isn't all that hard if you know it's coming and have prepared (or are using a long-running, badge-powered strategy of some variety), but the first time through the game this fight is ridiculous.
*** The Shadow Queen is quite difficult, even for a final boss, as she has a very large amount of HP, she has several multi-hit attacks, she can act multiple times per turn, and her hands can even drain your HP.
**** Bonetail is likely to be harder then the Shadow Queen because odds are, you'll be half dead by the time you reach because of all the hard fights in the Pit of 100 trials.
** Cortez from ''Thousand Year Door'' is often considered on of the harder bossess because he has multiple parts to him that each get their own attack, meaning if you don't take those out he can land five attacks in one turn
* ''BreathOfFire 2'' certainly had a fun one in the form of Barubary. Most of the game can be fairly easy, even fights like Guardeye. But since you have to fight Barubary alone to get the location of a great item, and he's super-difficult even with a full team...
** Algernon and Wildcat definitely count as well. The main problem is that the ReviveKillsZombie method for beating them is a ''massive'' GuideDangIt in both cases. And in both cases, when you're having trouble with said bosses and check a guide for them... you realize [[LostForever you missed your chance]]. Tough luck.
*** To clarify: when you fight Wildcat, you fight him ''without any of your weapons or armor''. The trick to beating him is to use Ryu's Elemental Dragon attack. Don't have it yet? Well, just use that party member you just got in the most unintuitive fashion imaginable to get it. Did he leave your party already? Well, just beat Wildcat to get him back! As for Algernon, there is a way to skip this fight entirely. It involves using your '''one''' Owl Fruit in the right one of those eight holes you see up ahead. Too bad there's no way whatsoever to distinguish the "right" one from the "wrong" ones, huh? If you used your Owl Fruit, you now have no choice but to fight Algernon.
**** That's only if you choose to comply with the regulations, which people may not know about. You have to fight bouncers at each checkpoint where you don't follow the rules, but that's preferable to going into the fight without your equipment.

** The Battle Of The Three Bridges. You fight three Nexus Animated, which are much stronger versions of the regular Animated roaming the gardens. Both are assisted by two normal Animated. The Kokeshi Nexus is arguably tougher than Katsumi's Doll. The Drum Nexus can play kickball with you, and has a nasty AOE attack. And the Lantern Nexus is way tougher than any of the other enemies in the area, and only spawns at night. (Meaning if you don't kill it before the sun rises, you have to wait an hour for it to respawn again.) And if you get too close to the edge of the bridge, there are still exploding Fluffs.
** OMGWTF softens you up with six waves of attacking [=OMGs=] first, and ''destroys'' new players who think they can take it on. The Predator Commander roams the Old Aqueduct area freely and will inevitably find you when you're farming Pups or soloing. Stone Coatl and the BonusBoss MemeticBadass Landshark have both been known to vex even CL 10 players. ''zOMG!'' can be NintendoHard for those who came in expecting just another of GaiaOnline's silly little Flash games.
** You think ''those are tough?'' Stone Coatl is the definition of ThatOneBoss. He takes all the annoying bits of these previous fights and [[UpToEleven turns them up to eleven.]] The fight starts with [[GoddamnedBats Tiny Terrors and Witch Doctors]], the second of which can heal their allies and slow you down considerably. After each wave of Animated, you fight a Mask of Death and Rebirth, which could be considered [[ThatOneBoss That One Particularly Strong Monster Who Will Kill You Over and]] [[OverlyLongGag Over Making You afraid to go to Otami Ruins, spam your defense rings, and flee in terror while simulataneously repeating your favorite manta, "Ohcrapohcrapohcrapohcrapohcrapohcrap..." over and over.]] And over. And the last wave of monsters before you even fight the boss ''itself'' are Bladed Vases which have a ridiculous area of effect attack that deals heavy damage in a circle to anyone even kind of sort of near it. Oh and if you don't work fast, the vases can easily wipe out a party because they keep spawning until a certain number is reached. Finally, when you reach Stone Coatl, he has the most HP out of any boss you've fought, has several different attacks, one of which ''knocks you back across the entire screen'' when you've been to close to him during the fight, and he spawns an infinite number of Animated which consist of the types previously mentioned. It's no wonder so many people get [[StopHavingFunGuys incredibly serious and demanding towards members of the crew]] when finding people to fight it. Stone Coatl is easily harder than the final boss.
*** Oh, and you have to kill Stone Coatl in order to move forward in the game and reach the final boss. If you can't beat it, you need to grind. And grind and grind. Before player got to choose a boss's difficulty, players could spending a lot of time orb farming in order to become strong enough to even get past the waves of Animated!
** The Landshark is entirely optional and isn't ThatOneBoss because it's fully intended to be incredibly difficult. It's not frustrating because it's not required for you to defeat. You don't even get a quest to beat it! All it does it drop nice loot. Landshark is more of a SelfImposedChallenge than anything.

** For regular non-Elite bosses, it is highly probable that either one of the two [[CircusOfFear Carnival of Shadows]] boss types will blow away your character's defenses and kill you so very dead.
*** The Carnival archvillain Madame of Mystery is not fun either. She's heavily resistant to most kinds of damage, requiring the use of a temporary power to defeat; on top of that, she can [[ManaDrain quickly floor your endurance]], leaving you helpless.
*** Also, Kadabra Kill. Multiple mezzes, a healing aura, and a pet.

** D'Arboleth is lots of fun with instant-death spells. If the party significantly outlevels him (possible, depending on how you've developed your characters), he's not that hard. If not... LuckBasedMission comes to mind.
** The Thing From Hell, unless you knew its Achilles' Heel, was a straightforward and brutal slugfest.
** The Fiend Of Nine Worlds... fast, hits very hard, hits often, and has a pretty good chance of instantly killing your characters with a critical hit.
** The Beast Of A Thousand Eyes... just... the Beast.
* Gates of Hell seems to be ThatOneBoss in ''TheLastRemnant''.
** This troper would argue that Gates of Hell is the first fight that requires a decent understanding of the game mechanics, making it a [[WakeUpCallBoss Wake Up Call Boss]]. He's a fairly easy fight if you know one of the strategies that works on the vast majority of the game's bosses.
*** To be specific, the Gates of Hell has 2 free attacks that it can perform while it's in its turn, both which can hit all the deadlocked teams (it has multi-deadlock), not countingits attacks in its main attack phase, which means it can attack 3 times in a turn. The problem is that a lot of players will try to deal as much damage to the boss as possible, causing nearly all your teams to engage in deadlock with the boss, which will result in massive damages being dealt to nearly everyone. And if a group is dead, the boss will cast Pandemonium, turning the dead group against you. The best way to beat it is to keep only few teams to engage it, and let the rest acting as healers and rotate in if possible to maximize the survivability.
* ''PhantasyStar IV'' had [[ScrappyLevel Air Castle]], which was rather difficult on its own, besides having two bosses that could be ThatOneBoss. The first boss fight is three enemies who use extremely powerful combination attacks, followed by a very ''very'' long staircase with lots of random battles that consume your healing resources, leading to Lashiec, who probably was the single most difficult fight in the game. Oh, and you can't leave the dungeon. And there's very limited inventory space for healing items.
** There are some tricks that mitigate this somewhat. For the MiniBoss, concentrate all your attacks on only one of the three opponents. Only use your most power attacks, and target all single-enemy attacks to the same enemy. If you do this, it usually only takes two or three rounds to take out one of the enemies, and with one down they can no longer use their devestating Tri-Blaster combo, making it a pretty easy battle. As for Lashic, there's no easy trick to deal with him. He really is that one boss. The finaly boss of the game is actually easier to kill if you use good tactics, but Lashic just punishes you no matter how good your strategy unless you've grinded to ridiculous levels.

** It certainly doesn't help that previously your party was separated and you're stuck with Polka, Chopin, Beat, and Salsa. The characters aren't necessarily bad themselves (When Blossom Shower is combined with Harmony Chains, Polka becomes an ungodly healer), but the characters you were separated from, Allegretto, Viola, Jazz, Claves, and Falsetto, are better fighters than Chopin, Beat, and Salsa.

** And that's not all, you are dumped into the battle after a long cutscreen AND a(n easy) fight proceeding it, so you A: can't save (as you are in combat the whole time) and B: have to rush the screen to keep the shorter lived potion effects you have on active.
*** Unless you have boosted your [[GameBreaker Igni Sign]] as much as you could thoughout the game, in which case the fight is going to be an amusing stroll in the park as Azar is burnt to a crisp. With the maximized Igni his troper managed to beat him on the first try, exactly like all the other enemies of the last part of the game. The Beast from chapter 1 is probably a more fitting example of ThatOneBoss, as back then Geralt is still very weak and the fight can be a real nightmare.

**[[spoiler:Here's where it's interesting; the smaller piranhas only tell is that they open and close their jaws a lot faster, followed by a low cry. If your volume's too low you won't hear it. If they're facing upwards they'll attack Mario, if they're facing forwards they'll attack Luigi. Unfortunately if you attack mommy both smaller piranhas go nuts and start attacking AT THE SAME TIME. You need to take out the smaller piranhas if you want to take down mommy because they heal her when the colors match. It's not that the smaller piranhas have no tell, it's just that it's so crazily subtle that you might miss it if you don't pay attention, also the smaller piranhas are immune to one of the bro's hand powers. The red ones are immune to fire and the blue ones are immune to lightning. Interestingly they are weak against the other element, red is weak against thunder and blue is weak against fire.]]
** Not to mention the final boss fight, [[spoiler: Bowletta. Or rather, the ghost of Cackletta INSIDE Bowletta.]] [[spoiler:She]] has a HUGE arsenal of attacks, most of which attack both Bros., and several of which are a royal pain to dodge or counter. Plus, [[spoiler:she]] has LOTS of hitpoints, and likes to heal [[spoiler:her]]self. As time goes on, [[spoiler:she]] uses different attacks, and has several turns in a row. You're pretty much screwed if one of the Bros. is KO'd in the middle of those multiple turns, you're pretty much screwed, as your dodging and countering becomes much slower, screwing up your timing BIG time.
***Not to mention that you [[spoiler: start the battle with only 1 HP, and the boss will attack first without a specific piece of equipment.]] There are also [[spoiler: two arms and a head]] which you must defeat before [[spoiler: attacking the heart, which has double the amount of HP of the previous boss, which you did not have a chance to heal after it ended]]
** Trunkle. Oh dear God, ''Trunkle''. The thing has crazy defense, so that your moves which do twenty to thirty damage to normal enemies does... 3 damage, maybe 6 if you get a Lucky shot, on him. Plus every other turn, he'll inhale enemies to heal himself, and do damage to you if you don't jump properly. Eventually he breaks apart--you've won, right? [[MemeticMutation WRONG!]] He's now four tiny Trunkles, and if you don't guess which one is the real Trunkle and defeat it first, he reforms and you have to start all over again!
*** [[spoiler: There are two ways to attack him. The other is to attack the top of him (as opposed to the face area), if you're a high enough level. It has only about half of the HP that he would the other way.]]

** ''MarioAndLuigi Bowser's Inside Story'' continues the trend with the final boss, Dark Bowser and Dark Fawful Bug. Now, neither is difficult to dodge attack wise, not particularly hard to damage, but they take forever to kill. First it's Bowser vs Dark Bowser, then at 1000 damage he heals, throws a whole bunch of enemies, you have to dodge pretty much all of them and said boss himself to reach him, then hit his stomach, then suck up the Fawful Bug... and Mario and Luigi THEN get their turn. The bug thing itself has three legs, two glasses and the Dark Star as targets, so Mario and Luigi have to destroy all the legs and the glasses to reach the star... get about two turns of attacks against it, then it repeats from the first Bowser phase.
*** Use Snack Basket to destroy the legs and [[GuideDangIt Magic Window]] to take care of the rest.
** The Fawful Express. It's only attackable with the flame attack (use DS microphone), has a semi turn timer you need to defeat it in, the mountain halfway through also becomes a giant mech and there are at least four different attacks to dodge.
*** Your lungs will feel like burning bags of sandpaper filled with needles after this fight.
** Princess Peach's Castle. It's MarathonBoss time for Bowser's giant battle form.
** Woe be to ANYONE who attempts LowLevelRun -ning the games, given your level factors into the damage. This troper spent ''45'' turns trying to kill Alpha Kretin at Level 7, who promptly gave enough EXP to get to Lv.10. Most players would be around 15-20 by now. Oh, and also, No Equipment challenge. You are going to die in two hits. To '''everything.''' Defeating Midbus at Lv. 8 was impossible, but Lv. 9 was not, for at Lv. 8, getting hit on the ''first'' turn ''twice'' kills you outright (I had ''exactly enough HP'' to die in one turn.)

* ''EverQuest 2'''s Raid Battle against Venril Sathir qualifies for this in spades. Not only do you need 2 copies of the same item from a previous raid mob to even make him DOABLE (thankfully they aren't consumed by the battle), the fight is simply unforgiving of ANY mistake. Guy on statue duty lags? Everyone dies. Someone doesn't cure their poison? Everyone dies. Someone casts too much/not enough? Everyone dies. Venril Sathir decides to screw you by giving the same person both his curses at once? Everyone dies. Someone crosses the threshold of his room too soon? Everyone dies. Venril is the raid mob in ''EQ2'' responsible for more raid guilds breaking in half than any other. The kicker: hHe's not even an end of progression boss, he's in the middle of an expansion's progression. As this troper's guild put it: "Venril is the mob you fight when you want to make a guild that eats Avatars (the endgame raid content) for lunch feel like a bunch of level 10 idiots."
**Actually, in a recent patch, this particular boss had his difficulty reduced somewhat, in particular, you no longer have to be so extremely careful about how much mana you have. It can still be quite difficult, however.
* [[spoiler:Julius]] in ''{{Castlevania}}: Aria of Sorrow''. The previous bosses were all slow movers with a pattern of movement, so strategy amounted to "find the enemy's blind spot and sit in it". ''[[spoiler:Julius]] has no blind spot''. He ''will'' move around the field faster than Soma does without Black Panther equipped, he ''will'' find you, and he will ''end'' you.
** He does have a general blind spot: distance. Not to say you should be inactive, seeing as he seems to be the WakeUpCallBoss, but [[MasterKnight this troper]] generally doesn't even use items, especially if they fall under TooAwesomeToUse, and he had more trouble with Balore and--on his Hard Mode run finishing with level at low-mid 40s--Chaos, and his primary endgame weapon for the run was the [[spoiler:Ronginus Spear]], not the [[InfinityPlusOneSword Claimh Solias]] or [[spoiler:something that doesn't have the Holy attribute]].

** Recumen is difficult due to a very, very powerful attack that can be made to miss--if you bought some secondary cannons for your ship and fire both secondary and primary cannons on his attack phases. Nothing tells you to buy the secondary cannons, or that they're even available now. The {{Cutscene}} right before the fight shows that a focused attack knocks Recumen off-balance during [[WaveMotionGun Red Ray]], but you'll probably dismiss it as CutscenePowerToTheMax. If you pay attention and use this strategy, this fight becomes a pushover.
*** Belleza, however, does not. [[UknownTroper This troper]] went through every single ship-to-ship fight in the entire rest of the game with the constant impression that "Belleza was worse".
**** These fights become a little easier when you realize that you can use Green Magic on your ship, even though you don't have the Magic Cannon yet. However, if you don't have any MP left from the earlier dungeon, you are back to square one.
** Any of the bounty missions--''any of them!'' Even--nay, ''especially''--the very first ones. Why? Because those bosses ''level up with you'', meaning that if you were foolish enough to wait until a few dungeons after they appeared to go fight them... oh dear. Oh ''dear.''

** Ogar can give you some trouble - You don't have to worry about her summoning one of the most powerful monsters in her arsenal within the first couple rounds because she literally has only ''one'' kind of monster she just summons multiple copies of. But Guess what that one monster is? A chaos jile...and that ''is'' her powerful monster! Not only can they be rather scratchy pains in the arse, but when they use Consume, they not only heal themselves, but have a chance of inflicting ''an instant knock-out'' regardless of current health.

** '''Odette'''. She [[FlunkyBoss summons a constant stream of lost souls]], pushing the processor to the limit -- then when her health starts to flag, starts absorbing them to heal. Then there's her [[HighOctaneNightmareFuel killer legs]]...

** ''KnightOfLodis'' also has a few. Early in the game when you fight Aerial...my god she is ''insane'', stupid stage!! Then when you walk into one town, Nichart shows up and he's the first boss-only class you fight, and rightfully so as he can hit really hard with his Osiric's Spear. Ouch. Fortunately it can be rather easy from then-on, even if you don't use the InfinityPlusOneSword you find laying around.

** ItGetsWorse around Apollo, you have to keep Dad and at least ''one'' party member alive for the entire battle or else you get an automatic game over. And unlike the other fights, you don't get to redo it if you die because you destroyed Odin beforehand.

** If this is the first boss that comes to mind in the ''{{Lunar}}'' series, I doubt you played ''{{Lunar}}: Eternal Blue on the original Sega CD. Those who did had the displeasure of facing Borgan. Unlike his Playstation counterpart, he was a multiple-target boss, and three of his four parts could each cast a devastating spell once per turn. More swearing ensued from fighting Borgan than from a dozen blue shells in Mario Kart. Often makes me wonder why they call it NintendoHard rather than ''Sega CD Hard''.
* '''[[MagicalVacation Magical Starsign]] has two bosses that qualify for ThatOneBoss status: Lt. Mugwort (Puffoon, first visit) and the Holy Sapling (Gren, second visit).

* In ValkyrieProfile, before the battle with the big bad you have to get past his two "bodyguards", the first of which you'll remember for the rest of your days (especially if you were unprepared for the battle). Bloodbane the dragon can hit you really hard and absorbs massive amounts of damage before getting really nasty. By the time you nail him past half his health bar it is likely that it will start using the special magic "Gravity Blessing" which will kill all of your characters EVERY FREAKING TIME, and he will be using it every turn afterwards. Ok, you have that item that revives you when you die (but it has 30% chance of breaking) and that skill that might allow you to keep going on with little health, but you have to survive another pounding of "Gravity Blessing" or see it heal itself back to FULL HEALTH. In Valkyrie your party can do insane amounts of damage (as there is no 9999 damage cap) but that does not help much when the thing has 380.000+ hit points. Enjoy.
** Bloodbane is not terribly hard if you can generate large amounts of red gems and then spam magic against him every turn. The problem is that there are exactly two characters who can realistically generate enough gems without using a Gem of Activity--Lucian and Badrach. Lucian you have to [[LostForever send to Valhalla]] to trigger the event flags that let you get to that point, and Badrach is so useless normally that most players kick him out too.
** Fenrir the wolf, the other of the BigBad's two bodyguards, can also potentially be this, with similarly strong attacks...except a weakness to [[KillItWithFire fire]] means a sword you likely picked up several chapters before can kill him in one shot.

*** Speaking of Super Hard, he's even worse there, unless you're really high level his sword's pretty much a OneHitKill. On the other hand, if you get good enough to beat him on Super Hard consistently and have the patience for it, you can make that scary sword of his your own. [[RandomlyDrops Or you could get the weaker version that also drops on Hard.]]
**[[YourMileageMayVary Your Mileage May Vary.]] Yes, Humilias is fairly unforgiving of careless mistakes on the higher difficulties. But by then, you usually know the fight and his attack patterns are sickeningly predictable. It's one of those bosses that can mess you up if you don't know it, but also can be easily completed without even being hit when you do know it.
* Though she may be an optional boss, VagrantStory's Asura definitely qualifies. Several [[GameBreaker playthroughs]] and [[NewGamePlus New Game Plusses]] later, Asura still stands as a challenge to an unprepared player. It doesn't help that she comes at the end of the Iron Maiden: a three-layer dungeon inhabited by some of the hardest minibosses and mooks in the game. And there are [[NintendoHard no save points]].
** Which is probably a ''good'' thing as, after a certain point, you can't get out of said dungeon by backtracking, either.

* [[TheLordoftheRings The Lord of the Rings: The Third Age]] has some pretty easy enemies and bosses... until you reach the Bridge of Khaza-dum and join Gandalf in his face-off against the Balrog. Showing why everyone was afraid of him in the movie, the Balrog proceeds to open a can of whoop-ass on your party, with two powerful attacks that hit everyone and deal Fire AND Shadow damage AND drain your ability-using points, his flame sword and flame whip that hit only one person for HUGE damage, having a high evasive stat, very high defense, and more health than all of the previous bosses combined. The only character in the party who can do any appreciable damage to him is Gandalf; the rest of you are there to heal, buff the party, and be mangled.
** Unless of course you use Endure Shadow and suddenly the Balrog is just a long and tedious battle. Once you encounter the Final Battle against the Witch King, your understand why even Gandalf the White is worried about him. Having the best stats in the game BAR NONE, only slightly lower HP then the Final Boss, being able to counter you if you DARE attack him, AND having A Hit All Life Drain so powerful, 2 in a row is a guaranteed party wipe out. Just for kicks, he also can stun a character so they can't move, good luck if he does it to your healer. He does have an Achilles Heel though, so it's uite doable if you exploit it.
** Nah. Balrog racks up a good body count on your party, but all they're there for is for Idrial to keep putting the resurrection aura on herself and Gandalf while everyone else builds up skill points.

** I say we run away and nuke it from afar. [[MemeticMutation It's the only way to be sure.]]
** The original MassEffect has a recurrent That One Miniboss in the Thresher Maws. You fight them in the Mako, which some people would argue is [[InterfaceScrew quite]] [[ScrappyMechanic enough]], but that's not all. The giant worm also ''ignores your shields completely'' and is able to trash the Mako with [[OneHitKill one hit]] when you're unlucky and three hits if you are. It frequently disappears beneath the sand and reappears elsewhere, meaning in addition to shooting and dodging, you have to be constantly fiddling with the camera to stay on target. And even if you get the strategy down pat, it will still randomly hand you a CrackDefeat by [[ThatOneAttack spawning right underneath you.]] Luckily, you can avoid most encounters, but at least one sidequest forces you to fight one.
* A few hours into ''Labyrinth of Touhou'', you come face to face with Youmu Konpaku, who is almost guaranteed to give you hell. For starters, she's teamed up with her ghost half who rains down status effects on your party, while she devastates your whole team with her absurdly powerful sword attacks. Thankfully, the ghost goes down fairly easily. Youmu, on the other hand, has a whopping 24,000 hp, with the most you're capable of doing at best is 1000 or so. And about half the characters at your disposal are weak to physical attacks, the only moves Youmu uses, and die to them instantly.
** ''Labyrinth of Touhou'' has a ThatOneBoss list almost a mile long:
*** The Eientei trio, against whom you must kill Eirin and Kaguya at the same time or else face an instant game-over from either Astronomical Entombing or Danmaku Barrage.
*** Yuyuko, a.k.a. "Whoops, here's a multi-target attack with a 100% chance of instant death."
*** Yukari, who uses Djinn "I totally cribbed this from ''GoldenSun''" Storm to drain all SP from ALL your characters (including those in reserve). And she'll always use it in battle twice, including once just before her TurnsRed phase.
*** Rinnosuke, who has an absurdly long fight filled with several different forms, and is capable of inflicting every status effect in the game.
** And let's not forget the Plus Disk [[BonusBoss Bonus Bosses]]:
*** Bloody Papa. Two words: "Strengthen Jutsu".
*** Hibachi #1 and 2, who are like Eirin and Kaguya, only even more unforgiving, and with relatively infinite DEF or MND.
*** Utsuho, who busts out Giga Flare from out of nowhere without any warning at all.

** And topping it off is that you have to go against Reinhart and two other bosses simultaneously in a 3v1, and this time, all of them are at level 50. And Reinhart still uses the same monster, with the same instant-turbo-on-start ability.
*** Also, Reinhart has a star advantage (considerable speed boost) on fire terrain, which the last battle with him features.
**** And just to annoy you, losing this fight dumps you back to the beginning of the dungeon, meaning you need to fight another two tough 3vs1 races before you get a shot at Reinhart again (Unless you do SaveScumming).
** The boss preceding Reinhart, Santos, isn't that easy either. Like the Reinhart example right above, this boss has a large speed boost on the terrain that his stage uses a lot. To make things worse, he has great speed and acceleration, and a defensive skill that means just bashing into him won't do you any good. This troper had more trouble with Santos than Reinhart.
*** Oh, and see that 3vs1 race with Reinhart mentioned above? One of the other two racers is Santos. OhCrap.

** The Salabolg in the swamp is just as bad. He hovers over water out of melee range and will routinely spawn enemies to attack you. Fortunately, he does come in range of melee attacks - when he snaps his head forward to attack you, so you need precision timing to dodge and counter. And unlike Verminator, this is near the beginning of the game, you've only got two or three attack spells and you just got your first spear ten minutes ago so unless you grind it won't be at a high-enough level to hit him from range.

** Bloodbane is not terribly hard if you can generate large amounts of red gems and then spam magic against him every turn. The problem is that there are exactly two characters who can realistically generate enough gems- Lucian and Badrach. Lucian you have to [[LostForever send to Valhalla]] to trigger the event flags that let you get to that point, and Badrach is so useless normally that most players kick him out too.

*** But the fact that the way to weaken his one-hit kill attack is a bit more of a GuideDang it situation, he can be a bit of a That One Boss