NPCs and Course Bosses
Ancient Attacker/Stone Snake
- Evil Counterpart: Not exactly evil, but it's an aggressive, darker-colored, winged version of the docile Stone Snake you could ride inside of the ruins.
- Feathered Serpent: Downplayed since it's a statue: it has no feathers but it does have wings carved in a way that make them look feathery.
- Living Statue: A living snake statue with an aggressive streak.
- Snakes Are Sinister: Subverted. It is the boss of the area, but it is mainly protecting it from what it perceives as thieves.
- Warmup Boss: It is the first course boss in the game, and also the easiest — it is very hard to get hit by it.
Mermaids
The inhabitants of the Blue Side of Crystal Caves.
- Eyes Always Shut: For some reason, they never open their eyes.
- Jerkass: The mermaid that challenges you to a race for a Star is also really smug about it, saying that humans cannot be as fast as mermaids. If you lose, she laughs at you. However, this changes when Mario saves them from the Giant Fish — the same mermaid offers a genuine thank you.
- Ms. Fanservice: As close to one as an N64-styled Mario platformer can get: the mermaids are attractive and know it, with one calling Mario a pervert for staring at her.
Sea Monster/Giant Fish/Megalodon
- Sea Monster: It is a giant fish with sharp teeth. The episode in which it is fought even refers to it as such.
- Wake-Up Call Boss: Unlike the Stone Snake, the Giant Fish is more of a challenge, requiring Mario to get close enough to it to lure it into the cage, but not so close that it actually catches him. The difficulty shows that the bosses will not be as easy this time around.
Kamek (spoilers)
One of the canon Mario characters, Kamek is the boss of Dusky Doomed Dale. Kamek curses the town to be haunted by spirits, only to get captured by the townspeople.
- Arc Villain: Of Dusky Doomed Dale.
- Bitch in Sheep's Clothing: He pretends to be an innocent Toad falsely accused of witchcraft, but he actually is guilty of everything the townspeople have accused him of. Once Mario frees him, he later returns to try and burn the town to the ground.
- Burn the Witch!: Would have suffered this fate at the hands of the townspeople for cursing the town, had Mario not come along.
- Flunky Boss: If his spells miss Mario, they'll turn into Goombas. This usually results in the town being flooded with Goombas given how hard he is to hit.
- "Get Back Here!" Boss: While he can attack by slinging spells at Mario, the real challenge isn't dodging them, but chasing and hitting the slippery wizard.
- Nice Job Breaking It, Hero: Tricks Mario into recovering the wand used to curse the village, then leaves him to get arrested instead.
- One-Hit-Point Wonder: Kamek can only take one hit before fleeing. But actually landing that hit is an uphill battle thanks to the unpredictable, eratic way he flies around town.
- Screw This, I'm Out of Here!: Kamek doesn't die or explode like most of the game's bosses when you defeat him, he simply books it out of town while leaving his star behind.
- Walking Spoiler: The role that Kamek plays spoils the twist of Dusky Doomed Dale — mainly, that the witch really is guilty after all.
- Wounded Gazelle Gambit: Pretends to be an innocent Toad accused of being a witch by superstitious townspeople.
Bees
The inhabitants of Harried Honey Hive. They are a peaceful kingdom of bees that was invaded by an army of spiders.
- Adaptational Ugliness: Downplayed; the bees in Super Mario Galaxy had some scary-looking fangs but were otherwise cute. The bees here, while still cute, are a bit more insectish thanks to the mandibles in place of their mouths.
- Graceful Loser: The bee that challenges Mario to a race, unlike the mermaid from Crystal Caves, compliments Mario if he wins, calling him the fastest thing he has seen.
- The High Queen: The queen bee is one. Not only does she genuinely care about her people, but after asking Mario some questions about himself, she decides that humans sound wonderful and allows them into her hive.
- Virtuous Bees: They're very friendly, upstanding insects in stark contrast with the feral, aggressive spiders invading their hive.
Giant Spider
The boss of Harried Honey Hive. It is the leader of the spiders that have invaded the hive.
- Attack Its Weak Point: You'll want to ground pound the cross symbol on its body to hurt it, and it will do everything in its power to make that difficult.
- Giant Spider: As the name suggests. It is bigger than Mario himself, and about as big as the Queen Bee.
- Spiders Are Scary: Unlike the cartoony scuttlebugs, it is designed much like a real spider.
- Wake-Up Call Boss: If the Giant Fish from the caves didn't drive home the fact that this game's bosses are going to be tough, this thing drives it home with a sledgehammer.
- Would Hurt a Child: It leads its smaller spider minions on an assault on the hive, with one mission having its brood try to eat the Bees' larvae.
Kurma Koopa
- Attack of the 50-Foot Whatever: He is a giant Koopa who attacks the islands. Or so it seems, but he actually owns the islands, and is simply very territorial.
- Giant Flyer: He's so big that he could count as a small landmass.
- Turns Red: He literally turns redder with every hit, and when he does, he summons progressively more winged Goombas to block Mario from reaching his head.
Piantas
The inhabitants of Gamble Game Gallery, who come to play the many games the casino has to offer.
- Nice Guy: Three of them give Mario the cards needed to play the games that give the stars as a reward, and want him to have fun like them.
Viruses
The boss of Colossal Circuits. The trio of viruses from Dr. Mario return as computer viruses infecting the circuits. The blue one blows wind, the red one blows fire, and the yellow one inflates itself.
- Blow You Away: The Blue Virus can blow wind at Mario to push him away.
- Dual Boss: A triple variant. Initially they fight Mario one-on-one, but when he hits each one once, they all charge at him.
- Playing with Fire: The Red Virus shoots fire at Mario.
Main Bosses (Unmarked Spoilers)
Goomba Bros
- Big Damn Heroes: When Mario gets knocked into their cage, they help him beat Rashay with the Power Stars.
- Dual Boss: Both times, they are a triple variant, attacking you all at once.
- Heel–Face Turn: Initially they are enemies to Mario, but end up helping him against Rashay in the final battle.
- Recurring Boss: They are fought twice in the overworld, depending on how many stars Mario has.
- Terrible Trio: They are a trio of Goombas who show up to fight Mario, and can be a challenging fight, but story-wise are of little threat. They even help Mario in the end.
Bowser
- Boss-Arena Idiocy: For whatever reason, he chooses to leave a few Bob-Ombs hanging around the ends of the bridge that he jumps around despite the fact that they're the only way to hurt him.
- Disc-One Final Boss: Bowser, interestingly enough, isn't the main threat this time around, being defeated in the first major boss stage and then vanishing from the plot.
- Generic Doomsday Villain: While he isn't the main villain, Bowser is still causing trouble. But what that trouble is or whatever he's trying to accomplish is never elaborated on thanks to his lack of dialogue aside from an individual sign.
- Not Me This Time: He is not responsible for the moon falling, Rashay is.
- Walking Spoiler: Him not being the Big Bad this time around is a major twist.
Shadow Factory Boss
Dark Mario
- Evil Twin: He is a dark version of Mario.
- Expy: Of Dark Link, specifically the Ocarina of Time version. A dark, shadowy version of the hero who is encountered in a white room, initially appearing to be a harmless shadow.
- Giant Space Flea from Nowhere: Unlike every other boss, there is no foreshadowing of his existence, and what he really is goes unexplained.
- Mirror Boss: He has every one of the abilities Mario does.
- Walking Spoiler: While he has little impact on the plot, the boss of the Shadow Factory turning out to be a copy of Mario is a minor surprise.
Final Boss
Rashay
- A God Am I: He does this during the final boss fight:Congratulations! You've just gained the right to witness a god's semi-perfect form! Bow down!
- Big Bad: He is the one trying to crash the moon into the Mushroom Kingdom for his own entertainment.
- Clipped-Wing Angel: Downplayed. While he's still very tough in his second form, it doesn't change the fact that he's invincible in his first form.
- Dracolich: His final form is some kind of skeletal dragon thing.
Word of God is that his "perfect form" (which he doesn't achieve in-game) straight-up is a dragon. - Expy: Of Majora. A mysterious spirit with unknown origins that seeks to crash the moon into the planet and behaves cruelly towards everyone it encounters, viewing it all as a fun little game.
- It Amused Me: The reason for all his abhorrent actions is that it is all a fun game to him.
- Kick Them While They Are Down: Even after he has Mario in his grasp, he repeatedly punches him across the field to satisfy his bloodlust.
- Kneel Before Zod: He demands that Mario and the Goomba Bros 'bow down' to him during the final battle after declaring himself a god.
- Laughably Evil: He frequently makes jokes at Mario's expense.
- No-Holds-Barred Beatdown: Gives one to Mario at the end of the first phase of his fight, bringing him down to one health point.
- One-Winged Angel: After Mario gets powered up, Rashay transforms into a boney, snake-like dragon.
- Psychopathic Manchild: He views his heinous acts, including trying to drop the moon on the Mushroom Kingdom, as a twisted game. When he fights Mario, he also calls it a game, and acts like a child the whole time. When Mario manages to reach him, he angrily shouts that he found the game boring and will chase Mario instead. He then gives Mario a No-Holds-Barred Beatdown.
- Seemingly Hopeless Boss Fight: You can't really hurt him in his first form, and after he drains Mario's health to 1, he'll grab him and then throw him into the same cage where the Goomba Bros. were being held hostage. After Mario gets powered up by the Bros., Rashay transforms, rock music starts playing, and the final fight begins for real.
- Sequential Boss: And with two different boss themes to boot. For the first phase, he throws platforms at Mario, who must use them to reach him. Then he knocks Mario away and starts chasing him. The second phase requires Mario to Ground-Pound the head of his dragon form.
- The Sociopath: He aims to crash the moon into the Mushroom Kingdom, kidnaps Peach to extort Mario into giving him the Power Stars, and finally brutally beats up Mario himself, all without a shred of empathy or consideration for anything other than his own amusement.
- Suddenly Shouting: After Mario manages to reach him in the first phase:THAT GAME WAS BORING! I'LL HUNT YOU NOW!
- Troll: In his moon cellar, he forces Mario to toss himself into painful, damaging lavafalls in order to get to one of the switches needed to proceed. He also leaves Mario a taunting signpost explaining this.
- Vile Villain, Saccharine Show: The hack's relatively Darker and Edgier nature is all because of him and his plan to crash the moon into the planet. The game retains the whimsical nature of the Mario series, but anytime he shows up, the mood instantly darkens.
- Walking Spoiler: For the first half or so of the game, Bowser appears to be the Big Bad. It is not until later that Rashay reveals himself to be the true antagonist.
