Goddamned Boss / Pokémon

• Trying to catch practically any Legendary Pokémon will make them this. Knocking out a Legendary is easy, catching one is an exercise in frustration as they all have the lowest catch rate possible and you have to sustain continued attack from their moves while trying to catch them. It is not unusual to go through up to 30 Ultra Balls and Timer Balls or cause the Legendary to run out of PP causing them to faint from Struggle as the Random Number God proceeds to not let you catch them. The only real exceptions are Legendaries that are plot mandatory to catch plus the Gen VII Mascots in Ultra Sun and Ultra Moon. Of special note is Giratina in Platinum, whose moveset has a total of 30 PP because three of its moves only have 5 PP. This means that after it moves 30 times, it will immediately Struggle itself to death. If it's at 1 HP exactly, you have a 3% of catching it per Dusk Ball. Good luck.
• Erika from Pokémon Red and Blue can qualify as this, with two of her three Pokémon knowing the Wrap/Bind moves (which, back in the day, did continuous but light damage over the course of 2 to 5 turns) and two of them using the status-inflicting Poisonpowder and Sleep Powder. Wrap/Bind was obnoxious because it forced the player's Pokémon to stay in for however many turns it lasted for, all just to do a pittance of damage. And while Poison and Sleep are easily cured with Antidotes and Awakenings, it forced the player to waste a turn dealing with the status. This could make Erika very annoying if the player's Pokémon were unable to take hers out in one shot.
• Agatha is infamously annoying for any player doing a Solo-Character Run, to the point that she's been nicknamed "the Agatha Lottery." Her team consists of multiple versions of the Gastly line, plus Golbat and Arbok, and she heavily emphasizes status effects, as well as having a randomized chance to switch every turn. Since Gengar has very high Speed, it's likely to get off a Confuse Ray or Hypnosis on the first turn, dragging out the fight even further, and while it is weak to Psychic and Ground-type moves, it's also totally immune to Normal-type moves, which many Pokémon rely on for offense. This leads to cases where sometimes Agatha does nothing of importance and dies in five attacks, and sometimes she stalls you out and chips you to death.
• Among the legendary catchable Pokémon from the same game we have Moltres. It only has two attacking moves, Peck and Fire Spin. Fire Spin not only does continuous damage each turn but it prevents the Pokémon affected from switching out and in Gen I attacking.
• Falkner from the original Pokémon Gold and Silver can be this, due to both of his Pokémon knowing Mud-Slap, an accuracy-lowering move. And said move is super-effective against Geodude and Onix, who otherwise have a type advantage against Falkner's Pokémon. (Not to mention that Geodude and Onix are generally slower and acts after Falkner's Pokémon.)
• Lugia in HeartGold and Ho-Oh in SoulSilver learn the move Safeguard at level 65 (which blocks status effects for five turns), and are encountered at level 70. Because of this, you can count on them to spam it throughout the fight, especially later on once they've run out of PP for their attacking moves (and all their attacking moves have really low PP). This makes putting them to sleep or paralyzing them far more difficult, driving down their already low catch rates.
• There's also Pre Gym Leader Justy from Pokémon Colosseum, who uses a combination of Double Team, Sand Veil, and Dig to keep you from hitting him. This leads to a tedious battle of spamming Faint Attack with Umbreon (if you taught it that; the Bite it comes with is usually more preferable) or Swift with Espeon (which no one does since it comes with Return).
• Juan from Emerald isn't too bad until his ace Kingdra. He's only weak to Dragon, but unless you have a Kingdra of your own (which can only be acquired from trade) all possible Dragons are vulnerable to a 4x effective Ice Beam. However, this Kingdra in particular comes with the infuriating combo of Double Team and Rest. He'll start setting up Double Team and if you get hits in, heal himself up with Rest, which will also remove any status afflicted on it. If you're particularly unlucky, you'll be dealing with all your attacks unable to land on a sleeping Pokémon and he'll wake up to attack, raise evasion, and heal. This can rectified with any moves that bypass accuracy checks like Aerial Ace, though.
• Candice in Pokémon Platinum, specifically. Her Froslass has the ability Snow Cloak, which ups her evasion by 20% in hailstorms. Candice's Abomasnow will also cause hail to be permanently in play. Froslass will follow up by using Double Team numerous times to increase her evasion even more. The only saving grace is that she'll likely go down in one or two super-effective hits if they connect.
• In Brilliant Diamond and Shining Pearl, Flint's Drifblim knows Minimize and Baton Pass. Meaning once he maxes out on evasion, he'll then pass the boosts to Infernape and be incredibly frustrating. He also knows Will-o-Wisp and Strength Sap for both crippling your team and maintaining longevity. Thankfully, the move Taunt will render him useless. However, he can be a difficult curveball for the unprepared player, especially one who doesn't have knowledge of competitive play.
• Grimsley's rematch team in Pokémon Black 2 and White 2, mainly for Liepard. She's already fast enough, but she has the Unburden ability too. She'll always start with Fake Out, which will consume the Normal Gem it holds and makes her go even faster and causes you to lose a turn due to your mon flinching (unless they have Inner Focus). Then she'll screw with you more because she knows Attract, which causes a status effect that wastes a turn half the time- and since this Liepard is female, and many species of mon have skewed gender ratios in favor of males (especially the starters)... you can expect to not be able to fight half the time. She also knows Sucker Punch to go first if you're using a move (given that there's a good chance that you'll be unable to attack), just to make things more annoying. And this is his first mon.
• In Black 2 and White 2 in the Pokémon World Tournament: Winona, specifically her Altaria. While most of the gym leaders will either give you an even battle or just murder you outright, Winona's Altaria seems designed specifically to cause hair pulling. Of its four moves, only one is damaging (Dream Eater) and it only works when your mon is sleeping. The others put your Pokémon to sleep, preventing them from attacking and making them vulnerable to Dream Eater (Sing), recover health (Roost, and also Dream Eater if it works), or boost Altaria's defense (Cotton Guard). So a typical battle has her put your mon to sleep with Sing, heal any damage you may have done with Roost, and then bulk up with Cotton Guard and proceed to use Dream Eater until your Pokémon wakes up, in which case you had better hope you get a Super Effective Critical Hit before you get put to sleep again. It's not quite That One Boss, because unless your mon is extremely vulnerable to Dream Eater, Altaria can't cause much damage, but its moveset seems basically designed to drag the match out as long as possible and make you waste all your good moves trying to KO Altaria before it can heal itself.
• Deoxys in Omega Ruby and Alpha Sapphire. Before you can even encounter it, you have to go through capturing Rayquaza, battling Zinnia (who can be defeated in two minutes), and sitting through several minutes of cutscenes, all without saving. Once you finally get to Deoxys, it's a pain if you're trying to capture it. Deoxys is so strong that it can easily obliterate your Mega Rayquaza in one hit with Psycho Boost, and Hyper Beam can deal some serious damage too. Then it starts spamming Cosmic Power to buff its defenses and Recover to heal any damage you can deal to it. And if that's not all, it also has an abysmally low capture rate and just will not let itself be captured. If you didn't use your Master Ball, there are two options: KO it and return later^note there's no indication it won't be lost if you knock it out, and trying again requires you to re-enter the Hall of Fame and return to Sky Pillar, or despair endlessly trying to capture it the first time around. Remember: you have to sit through ten minutes of battles and cutscenes before you can fight Deoxys.
• Primal Groudon from Omega Ruby/Alpha Sapphire is not especially hard to defeat, but catching it is extremely tedious. Fire-Ground, as a type combination, has precisely two weaknesses out of seventeen types. One of those is Water, which is cancelled by Groudon's ability and, if you have means to subvert that ability, would likely kill it dead instead of weakening it appropriately. And when you do weaken it... It knows Rest. Which restores all HP. So basically, if you want to catch it, you have to weaken it about ten times over. And unless you have a Ground type on hand (and Primal Groudon has a very high Defence stat, which most Ground moves would go up against), you're going to be doing normal damage to it at best. As said, making P. Groudon weak is doable. Keeping it weak is a headache. Like any Rest-abuser, moves like Worry Seed and Heal Block will stop it being able to heal... but those are moves with very specific applications, and even if you have a Pokémon that can learn them there's a very reasonable chance you simply don't have them learned right that moment.
• Any and all roaming Pokémon, no matter the game. For starters, they run at the first chance they get to a random spot on the map, which changes when you go to a different route or town/city. Next, they're all Legendary Pokémon, meaning that you only get one chance per match to catch a Pokémon with the lowest possible catch rate. Thirdly, trapping moves like Mean Look only work so long as the user remains in battle (outside of using Baton Pass), and trapping abilities only work if the Pokémon was sent out at the start of the fight. Finally, if you want a certain kind of Nature and/or Hidden Power type on them (such as a Timid Raikou with an Ice-type Hidden Power), you'll be pleased to know that their Natures, IVs etc. are all decided not when you first battle them, but as soon as they start running around the map, and the only way to reset them afterwards (from Platinum onwards) is to KO them and beat the Elite Four again to make them respawn, hoping above hope that the next spread is what you're after. Thankfully, statuses and damage inflicted remains when you run into them again, and the Master Ball makes catching them after you hunt them down easier, but there's often only one per game, and there are more than one of these arseholes.
  • Raikou and Entei are perhaps the worst roaming legendaries. Along with all the abovementioned points, they also know Roar — meaning that if you manage to stop them from fleeing, they'll try to make you run away instead. Even worse, if they pulled this off in FireRed and LeafGreen, they would disappear entirely, preventing you from ever catching them. Oh, and while roamers are entirely optional, if you want Ho-Oh in Pokémon Crystal, you need all the beasts; these two included.
  • The legendary Kanto birds in Pokémon X and Y are a new breed of roamers — this time, they'll split before you're even allowed to send out your Pokémon. You need to hunt them down around ten times before they finally settle down for good in Sea Spirit's Den, where they can be fought without running away.
• Tapu Fini in Pokémon Sun and Moon will test your patience to the extreme. Firstly, its ability automatically summons Misty Terrain, meaning you won't be able to inflict status on it for five turns. It has Aqua Ring to regenerate the damage you do to it, along with having very good defenses and a strong defensive typing making wearing it down harder. It also has Muddy Water to wear you down and lower your accuracy, and Hydro Pump if it feels like just killing you instead. Park a Grass/Dragon/Water-type in front of it to resist the hits? It has Nature's Madness, which halves your HP and puts you in danger of being knocked out even with the type resist. The only thing keeping it from being That One Boss is the fact that it doesn't hit as hard as the other Tapus, the Ultra Beasts, or the cover legendaries, making it merely annoying instead. Expect to sink a while into catching it, and god help you if you're resetting for natures and whatnot.
• In Pokémon Sword and Shield, the only thing keeping the Gigantamax forms of Pikachu and Eevee from being That One Boss is that, not being fully evolved, their defenses are paper-thin. However, they both tend to run essentially the same strategy of trying to stop the player's side from getting to attack at all. Pikachu's signature move, G-Max Volt Crash, paralyzes the entire party, including Ground-types that the attack itself can't even hit, and then spams Double Team to try and make sure any Pokémon that do get to move will miss anyway. Eevee manages to be just as annoying; its signature move, G-Max Cuddle, inflicts infatuation on any opposing Pokémon of the opposite gender from Eevee itself, forcing them to stand by and do nothing 50% of the time, and as salt in the wound, Eevee also comes knowing Sand-Attack to lower the player's accuracy even further and Endure, a move that guarantees itself a Last Chance Hit Point for a full turn, dragging the fight out even more.
• Cotton Down Eldegoss is extremely tedious to fight in a Max Raid. While Eldegoss isn't strong enough to be that dangerous offensively, or quite durable enough to stall out the 10-turn limit, Eldegoss's Cotton Down ability makes it a total pest on a meta level. Cotton Down is an ability that activates every time Eldegoss is hit by a damaging move, which gives off cotton spores and lowers the Speed of everything except itself. This by itself is only mildly annoying, but the specifics of Cotton Down being on a Max Raid boss is what makes it truly aggravating: the ability activates every time Eldegoss gets hit, it gives a speed debuff to everyone else, and there are four Pokémon attacking it in one turn, meaning you'll be stuck sitting through as many as 16 unskippable "X's Speed fell!" text boxes per turn, four times each on all four raid members. It gets worse if you're unlucky to get saddled with someone who uses a multi-strike move on Eldegoss; Cotton Down will activate on each individual hit of the move, creating even more text boxes. And if you thought this battle couldn't get even more annoying, well; you'd be sadly mistaken. When a Raid Boss uses its "shockwave" to clear its status effects, its stat drops, and your side's stat boosts, it also clears your side's stat drops, meaning that you get to see all of those text boxes all over again. Also, a 5-star Eldegoss puts up 2 shields with 6 bars apiece. Have fun with that. You will want to bring in as many Pokémon immune to Cotton Down as you can, because the alternative is signing yourself up for the Pokémon equivalent of (quite literally) watching grass grow.
• The Forces of Nature in Pokémon Legends: Arceus. For starters, they're surrounded by a small storm that has to be dispersed with a thrown items before you can catch or battle them, though it doesn't stay down for long. They also fly around the area at a breakneck pace as soon as they spot you, making it difficult to aim items or catch up with them, and they're found in areas where stealth is difficult and other wild Pokémon are present, including Alphas, who will all proceed to interfere with your attempts at capture. They can also all block your way with tornados, and if Enamorus hits you with one it'll cause confusion and throw off your inputs. Tornadus and Thundurus are also only found during specific weathers.

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