Main characters: The Mario Brothers | Allies | The Koopa Kingdom (Bowser — Bowser Jr. — The Koopalings — Other High-Ranking Subordinates — Bosses) | Assorted Nasties
RPG characters: Super Mario RPG | Paper Mario (64 — The Thousand-Year Door — Super — Sticker Star — Color Splash — The Origami King) | Mario & Luigi (Minion Quest: The Search for Bowser)
Spinoff series: Yoshi's Island | Luigi's Mansion | Mario Golf | Mario Tennis | Super Mario Maker | Donkey Kong series (Kongs) | Wario series (Wario and Waluigi)
Crossovers: Punch-Out!! | Super Smash Bros. | Mario and Sonic at the Olympic Games | Skylanders | Mario + Rabbids Kingdom Battle
Other media: Super Mario Bros. (1993) | The Super Mario Bros. Movie
Koopa Kingdom Bosses that aren't Bowser, his family, or Kamek.
- Breath Weapon: He uses the same moves as Bowser, he will launch fireballs at Mario.
- Chuck Cunningham Syndrome: Outside of a few allusions, he hasn't been seen since Lost Levels.
- Depending on the Writer: His nature varies depending on where you look: Early Japanese supplementary material (outside of one instance) indicates that he's Bowser's younger twin brother. Later material retconned him into being another Fake Bowser although some sources such as the Japanese version of Super Smash Bros Ultimate and Encyclopedia Super Mario Bros leave his nature more ambiguous.
- Drop the Hammer: He throws hammers at Mario.
- Palette Swap: He looks exactly Bowser, albeit with a blue shell and head note . In All Stars he looks the same as the Fake Bowsers although an unused blue palette for Bowser does exist, implying that he was meant to keep that trait.
- Recurring Boss: You can fight him in three levels, however you can just run past him.
- Skippable Boss: Nothing prevents Mario or Luigi from simply running past him to continue their way to fight Bowser.
A big Bob-omb who's watching the war between the pink and black Bob-ombs. As far as bosses go, he's pretty gracious when taking defeat.
- Affably Evil: Aside from being an antagonist, he has the personality of a gentleman and he would also compliment the player as well.
- Big, Bulky Bomb: Due to being the giant king of walking bombs.
- Braggart Boss: In Super Mario 64 DS he would constantly mention how awesome his mustache is.
- Chasing Your Tail: To beat him, he has to be grabbed from behind and thrown onto the ground three times. Don't throw him off the edge though; it's "against the royal rules" and will result in having to start the fight over.
- Flunky Boss: In his first battle in Super Mario 64 DS, he spawns regular Bob-ombs to assist him, because Yoshi is unable to pick him up.
- Graceful Loser: When you defeat him in Super Mario 64, he'll accept defeat and compliment the player along with giving them a star too.
- Hypocrite: In Super Mario 64, if you throw him off the mountain, he will jump back up and tell you it is not honorable to throw an opponent out of the ring. Thing is, though, that he will do the same thing to you, and force you to go back to the top of the mountain and go through his intro dialogue again.
- Inconsistent Dub: Was alternately known as "Big Bob-omb" in early appearances. Post Gamecube they've gone back and forth until the US version of Mario Party 9 settled on King Bob-omb with the UK following suit in Island Tour (the European version of Mario Party 9 still refers to him as Big Bob-omb.
- King Mook: Of the Bob-ombs, specifically the black ones (since the pink Bob-omb Buddies are benign and do not align with him at all).
- Light Is Not Good: He's a villain who sports white gloves.
- Manly Facial Hair: King Bob-omb takes great pride in his mustache. He tends to look down on anyone who doesn't have a mustache or has one he considers inferior to his own.
- No-Nonsense Nemesis: In Mario & Luigi: Paper Jam, he immediately decides to blow himself up when confronted on Mt. Brr and triggers a Time-Limit Boss battle where he needs to beaten in four minutes in real time (three in the Battle Ring).King Bob-omb: I can't lose to these puny brats! I'm a king! I... I have a moustache! Oh. Right. So do they.
- Promoted to Playable: He's a playable character in Mario Kart Tour and Mario Golf: Super Rush.
- Tactical Suicide Boss: When he fights Yoshi in Super Mario 64 DS, he spawns Bob-ombs, something he didn't do in the original. Since Yoshi cannot pick him up, and his only method of attacking the king is to use his own Bob-ombs against him, he would be better off just sticking to his old tricks.
- Taking You with Me: His attempt to take out the Mario Bros in Paper Jam involves blowing himself up to destroy them in the explosion.
- Terse Talker: Contrasting his extravagant speech in his debut, he doesn't talk much in Paper Jam.
- Throw Down the Bomblet: He gains this attack in Super Mario 64 DS, throwing smaller Bob-ombs at the player.
- Time-Limit Boss: He appears as a late-game boss in Mario & Luigi: Paper Jam. Players are given four minutes in real time to defeat him (three minutes in the Battle Ring), and if you run out of time, he blows up in your face. You can add a minute to the timer by deflecting his red bombs back at him.
- Took a Level in Badass: He was the first boss in 64 and 64 DS but in Paper Jam he is the last boss fought before Neo Bowser Castle and spends most of the game running the operation that rains papercraft environments on the Mushroom Kingdom and is willing to destroy himself if it means taking out the Mario Bros.
- Warm-Up Boss: The first boss of Mario 64 who holds the very first star of the game. All he does is walk around very slowly and try to pick Mario up and throw him. All Mario needs to do to win is do the same to him three times, and Mario moves much faster.
King of the Whomps, he's tired of gravel being ignored. He wants some respect and takes his anger out on Mario.
- Attack Its Weak Point: The bandage on his back is his weakpoint.
- Flunky Boss: In Super Mario Galaxy 2, he creates Whimps to help him.
- King Mook: Of the Whomps and possibly the Thwomps.
- Leaning on the Fourth Wall: In Super Mario Galaxy 2, if you die to him and then return to fight him again, he will only get part of the way through his speech before claiming to be tired of giving it every time, and jump right to the battle.
- Red Eyes, Take Warning: He's a boss with red eyes.
- That Makes Me Feel Angry: "It makes me so mad!"
- Took a Level in Badass: In Super Mario Galaxy 2, where he's a boss in one of the last levels of the game. He's much bigger than in 64, so it's harder to get up onto his back when he slams the ground, and the vulnerable area you need to ground pound is smaller. Additionally, getting flattened by him is now an instant, squishy death, he can kill you by stepping on you or crushing you under his fist, he can summon Whimps to assist him, and he has a Shockwave Stomp attack. However, he still goes down in three hits, as is tradition.
- Trick Boss: In Super Mario Galaxy 2, the Whomps are bigger than in 64, so one wouldn't be blamed for thinking the Whomp that's walking where the Whomp King was in 64 was the Whomp King. But it's not, and when one beats that Whomp, you can access the underside of the fortress/planet, where the Whomp King is hiding out.
Nothing really sets him apart from the other Bullies, other than his large size. That might be all that matters to the dim-witted creatures.
- Degraded Boss: The 2nd mission of Lethal Lava Land, Bully the Bullies, features another Big Bully, while more Big Bullies reappear in Super Mario Maker 2 by enlarging a Bully with a Super Mushroom.
- Green and Mean: A villain with green shoes.
- King Mook: Of the Bullies.
- Ring-Out Boss: Like all bullies, Big Bullies can only be defeated by pushing them off their platforms.
A pair of giant hands with eyes on their palms who guard the center of a pyramid. Like all the other bosses, they are not happy to see Mario.
- Attack Its Weak Point: His eyes are his weak points.
- Dual Boss: The two hands are fought together.
- Eyes Do Not Belong There: He's got eyes on the palms of his hands.
- Giant Hands of Doom: His whole identity. Oh, and he's made of stone.
- Go for the Eye: It is in his name.
- Punny Name: Eyerok=Eye+Rock/I Rock!
- Rock Monster: He is a pair of large animated hands made out of stone.
Big Mr. I
A giant version of the Mr. I enemy who hides out in the attic.
- Creepy Blue Eyes: This is pretty much what it is.
- Faceless Eye: It is nothing but a giant eye.
- King Mook: Of the Mr. Is.
- Punny Name: Mr. I = Mr. Eye.
A large Bully made of ice who must be defeated to get a Power Star. Like normal Bullies, he charges at you and must be knocked out of his ring, this time into icy water.
- Bullfight Boss: Fights via charging at you.
- King Mook: Of the Bullies.
- Ring-Out Boss: Like the others, with a frozen lake below to hurt him or you. Notably, he is the only Bully that can be pushed by Yoshi's fire breath.
- Spikes of Villainy: Downplayed. He has a giant spike on his head and is evil.
Bigger and stronger than the Chill Bully, the chief knows a few more tricks than the average Bully. He, like King Bob-omb, is also quite proud of his 'stache.
- Braggart Boss: Like King Bob-omb, he is constantly bragging about his mustache.
- Co-Dragons: With Goomboss and King Boo, as Bowser has them guard Mario, Luigi, and Wario in Super Mario 64 DS.
- Developer's Foresight: He has Yoshi-specific dialogue which can only be seen via a glitch, as normally he can only be reached by Luigi. This is in stark contrast to King Boo, who (except in the Japanese version) only brings up a blank dialogue box when confronted by Yoshi."Hmm? I see you have no mustache. Poor, bald, little creature. It's not a fair fight for you, but luckily, I'm not a fair fighter. Let's go!"
- King Mook: The biggest Bully. He's a King Mook for the King Mooks.
- Manly Facial Hair: He boasts about his mustache A LOT. He'll also be quick to insult Luigi over his facial hair, and is utterly distraught if he's (somehow) defeated by the hairless Yoshi.Chief Chilly: I simply cannot believe that I lost to a hairless pip-squeak like you! My mustache was my only joy. Now what am I going to do?
- Ring-Out Boss: He's just another Bully.
- Spikes of Villainy: He has a bunch of ice spikes on his head in the shape of a crown, with a big yellow spike at the center.
A mysterious criminal who resembles Mario. He uses his magic paintbrush to cause all sorts of problems on Isle Delfino. After the battle with Mecha-Bowser, he reveals his true identity: Bowser Jr.
- Calling Card: An "M" with two short vertical lines above it.
- Criminal Doppelgänger: Invoked as he impersonates Mario to ruin his reputation.
- Decomposite Character: Is separate from Bowser Jr. in ''Mario Golf: Toadstool Tour".
- Easy Impersonation: He's translucent and blue, yet the inhabitants of Delfino Plaza still can't tell him apart from the real deal.
- Late-Arrival Spoiler: Him being Bowser Jr. was originally a twist, especially since Sunshine was Jr.'s debut. In Super Smash Bros. for Nintendo 3DS / Wii U, Bowser Jr. transforms into Shadow Mario during his Final Smash.
- Mini-Boss: Unusual in that he's encountered in each level after you defeat the resident boss. This is because he always appears in Episode 7, while the main bosses as well as other minibosses appear anytime from Episode 1 to 5.
- Mirror Boss: He has all the same moves as Mario, minus FLUDD.
- Promoted to Playable: He's an unlockable character in Mario Golf: Toadstool Tour despite Bowser Jr. being playable in the same game.
- Recurring Boss: You have to defeat him in all seven worlds to get to the final level. He's also fought four times in Delfino Plaza: First When he's attempting to kidnap Peach, second when he's taking a Yoshi Egg, third when he's carrying a Turbo Nozzle, and last when he's taking a Rocket Nozzle.
A species of giant, sludge-covered Piranha Plants.
- Color-Coded for Your Convenience: There are three different kinds, which are distinguished by their different colors.
- Depending on the Writer: The Nintendo and Perfect Stategy guides call them "Gatekeepers".
- Flunky Boss: The brown and black ones spawn Swoopin' Stus.
- Kill It with Water: They are defeated by squirting water into their mouths.
- King Mook: One of two Piranha Plant bosses in the game, the other being Petey Piranha.
- Meaningful Name: The "Proto" in their name is short for "prototype", which fits their Warm-Up Boss status.
- Mini-Boss: Primarily of Delfino Plaza, in which it tries to prevent Mario from gaining access to the first three levels.
- No-Sell: Only squirting water into their mouths does damage to them. If you squirt them anywhere else, nothing happens.
- Recurring Boss: Encountered five times total. One pink, yellow, and orange one, two brown ones, and two black ones.
- Stationary Boss: They never move from their designated positions.
- Zero-Effort Boss: The very first one fought at Delfino Airstrip has no means of attack, so the only way to lose to it is to deliberately run into it and kill yourself via Collision Damage. Even later variations that spawn Swoopin' Stus to assist aren't safe from this, as players can easily find a place where the Swoopin' Stus can't get them while also getting a good enough shot at the Proto Piranha without ever having to move.
Petey PiranhaSee this page.
A massive Blooper who is primarily fought in Sunshine by ripping off his tentacles and his sucker. While he hasn't become as popular as Petey Piranha, he's appeared in a few other games, making him a recurring foe for Mario.
- The Bus Came Back: He returned in Paper Mario: Sticker Star as the third boss, this being his first major role since Super Princess Peach.
- Combat Tentacles: Those giant tentacles aren't just for show and are primarily used for slapping Mario and friends. He also uses them to play tennis!
- Dance Battler: In Sticker Star. The tone of the music and whatever dance he's doing determines his next attack.
- Giant Squid: Is a giant Blooper, which is a squid.
- Hoist by His Own Petard: In Sticker Star, if Mario uses a Sponge Sticker as Gooper Blooper is preparing his poison spray move, the Sticker will absorb the poison and shoot it at Gooper Blooper causing him to be poisoned instead and miss all his attacks! The music switches to a Theme Music Power-Up of the Super Mario Bros. Level 1-1 music after this.
- King Mook: Of the Bloopers.
- My Rules Are Not Your Rules: In Mario Power Tennis, in Gooper Blooper Volley, Gooper Blooper throws one of his racquets at the ball and grabs another one from a box next to him.
- Poisonous Person: Can spray poison at Mario in Sticker Star. This can be turned on him with a Sponge Sticker.
- Purple Is Powerful: Purple in Sticker Star and uses powerful attacks, namely slapping Mario with his tentacles and spitting a poison spray.
- Recurring Boss: He is fought three times in Sunshine.
- Snot Bubble: Forms one of these when he falls asleep with the Calm vibe at low health in Super Princess Peach. Peach can pop it by attacking it with Perry a few times or instantly with Rage.
- Your Size May Vary: In Mario Super Sluggers, he's as big as a cruise ship!
Cataquack-like monsters that appear in the second episode of Gelato Beach. They walk on the top of the mirrors that reflect the sunlight toward the the heating device that keeps the Sand Bird's egg warm, and without it the bird won't be able to break the egg to be born. Thus, Mario has to defeat the Plungelos so the mirrors can resume their function.
- Depending on the Writer: Bradygames's Strategy Guide calls them Chuhanas (their Japanese names), the Perfect guide calls them Giant Cataquacks and Prima calls them Red Cataquacks.
- Mini-Boss: They're fought early in Gelato Beach, and defeating them will unlock the episode where Mario has to confront Wiggler (a main boss).
- Ring-Out Boss: They can only be defeated by pushing them into the mirrors' edges (with the help of FLUDD's water, as touching them is ill-advised) and then performing a Ground Pound from the opposite direction to bounce them away.
- Wolfpack Boss: There's one Plungelo in the first mirror, two in the second and three in the third. Six in total.
Wiggler is found sleeping on a heating device that was supposed to help the Sun Bird hatch. Upon the defeat of the Plungelos, the restored reflections of the sunlight will wake him up and make him fall, and the creature is not happy for that.
- Berserk Button: Wigglers have bad tempers as it is, but this Wiggler goes into a rampage after Mario wakes him up.
- Don't Wake the Sleeper: Not unless you want a caterpillar the size of a small train to destroy everything in its sight.
- Flipping Helpless: Mario has to use the Dune Buds to create sand dunes to knock over the Wiggler. Mario then has to Ground Pound a specific segment to any damage.
- King Mook: Of the normal-sized Wigglers in the franchise, but in this game it's representing specifically the Plungelos and Cataquacks.
- No Body Left Behind: He turns into sand after Mario defeats him.
- Songs in the Key of Panic: The boss music speeds up after each hit.
- Unstoppable Rage: He is NOT happy about being woken up.
A giant robotic version of Bowser, Bowser Jr. sics the robot on Mario during their encounter in Pinna Park. Not to be confused with the other Mecha-Bowser from Super Mario Galaxy's Toy Time Galaxy, which is not a boss and is entirely different in appearance.
- Background Boss: Mario rides a roller coaster and fires missiles from afar to hit Mecha-Bowser.
- Breath Weapon: It shares Bowser's fire breath.
- Climax Boss: Defeating this thing triggers The Reveal that Shadow Mario is Bowser Jr. in disguise, as well as his motive.
- Evil Is Burning Hot: A villain who can breathe fire.
- Humongous Mecha: A giant mecha in the shape of Bowser.
- Macross Missile Massacre: Its main mode of attack is firing Bullet Bills at Mario.
- Robot Me: Of Bowser.
- Stationary Boss: Stands completely still during the boss fight in Sunshine.
A large, sentient silhouette in the shape of a manta ray. The electric goop it leaves behind causes Hotel Delfino to disappear.
- Asteroids Monster: Squirting it causes it to split into smaller copies of itself.
- Dark Reprise: Its boss theme is a much spookier version of the Proto Piranha's.
- Eldritch Abomination: It's a manta ray that oozes electric slime and splits into tinier versions of itself.
- Living Shadow: While it's not dark like a shadow, Phantamanta does share the same physical properties of one.
- Mini-Boss: It's the first major opponent faced in Sirena Beach, and defeating it will be necessary to restore Hotel Defino. However, the actual main boss of the level is later revealed to be King Boo (hence why Phantamanta's music is a mildly modified version of the standard miniboss theme).
- Punny Name: Phantom + manta.
- Shock and Awe: It leaves trails of electric goop wherever it goes.
- Turns Red: After all of its copies are sprayed into their tiniest form, the Phantamantas turn a pinkish-red and immediately start to home in on Mario.
A boss of the Boos exclusive to this game. Not the same King Boo who debuted in Luigi's Mansion; his Japanese name is "Boss Teresa".
- Does Not Like Spam: Spicy foods, peppers in particular.
- Dub-Induced Plot Hole: He's given the same name as King Boo in the overseas version when he's a separate character.
- Feed It a Bomb: To make him vulnerable to attack, Mario has to throw hot peppers into his mouth.
- Fire-Breathing Diner: After feeding him a pepper, he starts breathing fire.
- Flunky Boss: He can summon enemies to his aid with his slot machine.
- The Gambler: He hides out underneath the giant roulette wheel in Hotel Delfino's casino. His boss fight involves spinning a slot machine.
- King Mook: At least of the Boos of Isle Delfino.
- Large and in Charge: He's much larger then the other Boos in the game.
- Maniac Tongue: He's a villain prone to sticking out his tongue.
- Overly-Long Tongue: He uses it to spin his slot machine, as well as lick the fruit juice off his face if you try to throw fruit at him without feeding him a pepper first.
A monster eel that has some major dental problems. His teeth are so bad that they somehow infect the water in Noki Bay, meaning Mario and FLUDD must go and clean things up, yet again.
- Bizarre Alien Biology: He has two pairs of eyes on each side of his mouth.
- Gold Tooth: Actually a Shine Sprite.
- Lone Wolf Boss: Him being on this page is a technicality, as he's the only boss in Sunshine to not be affiliated with Bowser.
- Non-Malicious Monster: He never seems to be explicitly hostile to Mario, approaching him and deliberately exposing his teeth. He even occasionally seems to say "Help me." when a tooth is cleaned up.
- Scary Teeth: Teeth so dirty they pollute the entire Bay.
- Sea Monster: He's a giant humongous eel polluting the sea.
- Slippery as an Eel: A monstrous and scary-looking eel.
- Underwater Boss Battle: The entire battle is fought underwater.
- Walking Wasteland: Only because of gingivitis.
A giant owl who battles Peach in Super Princess Peach.
- Free-Fall Fight: Hoo destroys the platform in the fight putting Peach in free-fall in hopes of giving himself the advantage. But Peach thwarts him by utilizing her own Joy Vibe.
- Ominous Owl: A giant owl boss who holds a Toad captive.
- Proj Egg Tile: Hoo throws eggs at Peach, which hatch into baby owls if they land.
- Turns Red: He utilizes the Joy Vibe after taking a few hits.
- Weaponized Offspring: If Hoo's eggs land, they will hatch little baby owls who will attack Peach.
A large Ice Dragon who can shift into different forms. She is the boss of Gleam Glacier in Super Princess Peach.
- Barrier Warrior: Blizzaurus creates a barrier made of ice that makes her invulnerable to Peach's standard attacks. Even trying to use the baseball slide attack hurts you.
- Breath Weapon: In her dragon form, she can fire a blast of freezing breath from her mouth.
- Dinosaurs Are Dragons: A dragon named Blizzaurus.
- The Fair Folk: Her true form is that of a little Ice fairy, which she transforms into after she takes enough damage.
- Harmless Freezing: Getting struck by Blizzaurus' Ice Breath turns Peach into an adorable icicle, which doesn't hurt, but makes Peach vulnerable to her follow up ramming attack.
- An Ice Person: Her main power, fitting for the world she's fought in.
- Logical Weakness: She's an ice creature who uses a barrier. Fire should work, and luckily Peach has more than enough...
- Make Me Wanna Shout: In her fairy form, she gives a loud screech that rains large icicles down.
- Ramming Always Works: Will rev up and try to charge into Princess Peach. Unfortunately for her, she's not very fast.
- All There in the Manual: They all had their names revealed by the Official Nintendo Strategy Guide.
A mummified Pokey, Mummipokey is the boss for World 2. It attacks Mario by hiding beneath the sand and emerging to spit projectiles at him.
- Fangs Are Evil: Unlike regular Pokeys, Mummipokey has a toothy maw that juts out of its face.
- King Mook: Of the Pokeys.
- Mummy: A mummified cactus to be specific.
- Non-Human Undead: A mummified Pokey, obviously.
- Red Eyes, Take Warning: A red-eyed villain.
Cheepskipper is a large, fanged Cheep Cheep that serves as the boss for World 3. He hides underneath the water in the castle and leaps to attack Mario on his own.
- Flunky Boss: Regular Cheep Cheeps assist Cheepskipper during the boss battle by leaping out of the water.
- King Mook: Of the Cheep Cheeps.
- Waterfront Boss Battle: The fight with Cheepskipper happens on a bridge suspended over water.
A regular Goomba mystically enhanced to grow to a gigantic size to stop Mario in World 4. Because of his size, it doesn't need to change its normal strategies during the fight.
- Attack of the 50-Foot Whatever: A giant version of a regular Goomba.
- Make My Monster Grow: He starts as an ordinary Goomba, but becomes giant under the influence of a Mega Mushroom. That does not disprove the fact that Mario can turn the tables with his own Mega Mushrooms, though!
A tank piloted by a single Monty Mole, Monty Tank patrols the castle in World 6. It utilizes Bullet Bills and Bob-ombs for its artillery.
- Badass Normal: Unlike the other bosses, Monty Tank is a normal Monty Mole.... In a tank!
- Tactical Suicide Boss: If its driver didn't stick his head out every now and again, Mario would be unable to defeat the tank (unless he brought a Mega Mushroom with him).
- Tank Goodness: The Monty Tank is immune to most attacks and has a decent artillery.
- Turns Red: For every hit it takes, an extra level is added to the Monty Tank.
Lakithunder is the boss of World 7, a Lakitu who pilots a thundercloud. While mostly relying on his cloud to attack, Lakithunder also uses Spinies during his fight with Mario.
- Cool Shades: He wears these instead of the usual aviator goggles.
- Dark Is Evil: His shell is black and he's part of Bowser's army.
- Flying on a Cloud: He flies on his thundercloud.
- Flunky Boss: Lakithunder can throw Spinies as an attack.
- King Mook: Of the Lakitus.
- Plot-Irrelevant Villain: Nope. It's heavily implied they're the thunder cloud who attacked Peach's castle in the opening.
- Shock and Awe: He can shoot lightning from his thundercloud.
- Small Role, Big Impact: If they are the thundercloud that attacks Peach's castle in the opening, then that means they're the main reason why Bowser Jr was able to kidnap Princess Peach in the first place.
- Tactical Suicide Boss: Swooping down to attack Mario was a bad idea...
A prehistoric Piranha Plant that attacks Mario as soon as it's hatched. It is first fought in the Good Egg Galaxy.
- Chasing Your Tail: The primary way of defeating it is to knock its club-like tail into it.
- "Get Back Here!" Boss: While it chases you, you have to chase it around the moon to reach its tail.
- King Mook: Like Petey, it's a huge offshoot of of the Piranha Plants, but it's a dinosaur.
- Recurring Boss: You fight it once in the first game, and once in the second as part of World S's Boss Blitz Galaxy.
- Suspiciously Similar Substitute: It greatly resembles Petey Piranha. In the sequel, it gets its own Suspiciously Similar Substitute, Peewee Piranha.
An Octoomba boss who resides in lava, fought in the Good Egg Galaxy and Bowser Jr.'s Lava Reactor.
- Ash Face: In his second battle, his body is blackened and burned from the damage he took in the first fight.
- Cool Crown: It gets knocked off in the ensuing back-and-forth coconut hitting, though.
- King Mook: To the various Octoomba species.
- Mix-and-Match Critters: Has the head of an Octoomba, and a Blooper-like body.
- Oxymoronic Being: You wouldn't normally expect an octopus to live in a lava lake.
- Pivotal Boss: Physically, he won't move from his lava pool. You have to run circles around him to avoid his attacks.
- Recurring Boss: Fought twice in the first game, the second time with sinking platforms, and once in the second.
- Tactical Suicide Boss: He shouldn't shoot those coconuts...
- Tennis Boss: He's defeated by sending his coconuts back in his face. He will learn, and bounce them back at you until either one of you gets hit.
- Tentacled Terror: An evil, giant lava-dwelling alien octopus. He gets even creepier during his second battle, being colored black with red eyes.
A giant Mandibug fought in the Honeyhive Galaxy in Galaxy and the Puzzle Plank Galaxy in 2. He makes his appearance known in Big Bad Bugaboom and Bugaboom's Back.
- Attack Its Weak Point: Like his underlings, his back must be Ground-Pounded to hurt him.
- Big Creepy-Crawlies: He's a gigantic, flying beetle.
- Green and Mean: A green villain.
- King Mook: An even larger version of the Mandibugs fought through the galaxy you find him in.
- Punny Name: Bugaboom = Bug+Boom. Also, of the term "bugaboo", which can refer to a monster or an annoyance, of which he is both. In the second game, the level he is found in is also an example. It's called "Bugaboom's Back" because, well, He's Back!, but also because that's where you need to hit him.
- Turns Red: After one hit, he starts flying. When he's hit again, he begins flying faster and occasionally flips on his side to protect himself from Mario attempting to ground pound him.
- Villainous Breakdown: The more damage Bugaboom takes, the angrier (and more dangerous) he gets.
A planet-sized robot under Bowser Jr.'s control. It is fought in Bowser Jr.'s Robot Reactor.
- Battleship Raid: You run up the giant mecha's body as it attacks you with its guns.
- Colossus Climb: You don't fight it head on because it's way too big for that. Instead, you have to climb up to its cranium and trick some Bullet Bills into breaking the Grand Star out of its head.
- Giant Foot of Stomping: Before Mario can climb up Megaleg's... well, mega-leg, he has to make sure he isn't crushed underfoot.
- Humongous Mecha: Among the most gigantic bosses in the series.
- Level in Boss Clothing: See Colossus Climb above. You have to climb up this thing to destory it.
- Made of Explodium: The whole thing explodes spectacularly when it is defeated.
- More Dakka: Apart from its sheer size, Megaleg primarily attacks by firing Bullet Bills at Mario if he attempts to climb it.
- Motif: Aside from taking inspiration from the tripods in War of the Worlds, it bears a strong resemblance to a Snifit.
- Tripod Terror: Three legs, way bigger than Mario, and many, many, Bullet Bill Blasters.
A giant, female Magikoopa fought once in the Space Junk Galaxy and twice in the Deep Dark Galaxy. She uses the Power Stars she keeps to fuel her magic scepter.
- Dark Action Girl: Fights with magic and is a villainess.
- Distaff Counterpart: To Kamek.
- Evil Is Burning Hot: She's a Dark Action Girl who can summon fireballs.
- Fireballs: One of her main attacks is summoning fireballs which bounce around the arena.
- Flunky Boss: She'll summon two Magikoopas in the last stage of her boss fights.
- Green and Mean: A Dark Action Girl with green lipstick.
- King Mook: Her Japanese name is "Boss Kamek", Kamek being the Japanese name of the Magikoopa species, and she summons Magikoopas in battle, which implies that she's a high-ranking Magikoopa.
- Makeup Is Evil: She's a boss who wears lipstick.
- Power Floats: Notably, she doesn't even have visible legs!
- Recurring Boss: She's fought in the Space Junk Galaxy and Deep Dark Galaxy.
- The Smurfette Principle: She is the only confirmed female Magikoopa in the main series.
- Tactical Suicide Boss: She shouldn't have shot Green Shells at Mario...
- Teleport Spam: In her Deep Dark Galaxy fights, she will teleport after every spell, hoping to reappear where you stand.
- Tertiary Sexual Characteristics: Kamella is female and she wears lipstick.
- Wicked Witch: Due to being a female Magikoopa with a more elegant robe and longer hat, she rather resembles one.
- Wizards from Outer Space: She's literally a Magikoopa fought in space.
- Attack Its Weak Point: Hit the sac/button on his back to flip him, then the three on his underside.
- Boss-Arena Idiocy: If it didn't have those Sling Pods lying around...
- Giant Spider: And you have to tangle yourself up in his web to fight him.
- Mix-and-Match Critters: His body has the general look of a spider, with the proboscis, six legs, and wings of a fly.
- Pivotal Boss: An unusual horizontal 2-D version- it stays on his web while you run around the edges.
- Poisonous Person: Sprays toxins at you from every angle but his back.
- Attack Its Weak Point: The first step to damaging it is to hit the red button on its top that will retract its blades and make it possible to Spin.
- Battle Tops: Many smaller Topmen are found throughout the Battlerock Galaxy. This one is the biggest.
- Boss-Arena Idiocy: While the electric fences are supposed to be the consequence of the player being hit, Topmaniac is also vulnerable to them.
- Chainsaw Good: It's a top equipped with a buzz saw.
- Flunky Boss: Uses Topminis and Spiky Topmen in its fights.
- King Mook: The leader of the Topman Tribe.
- Recurring Boss: It would only be fought twice if it wasn't for the Prankster Comets, whick kicks its number of fights up to four.
- Red and Black and Evil All Over: Its color scheme is mainly black with red accents and its evil.
- Ring-Out Boss: You defeat it by knocking it into the electric barriers surrounding the ring.
A rock-armored ghost fought in the Ghostly Galaxy.
- Attack Its Weak Point: At first, the armor, then, its uvula when that's all broken away.
- Death from Above: One of his attacks is to try to smash you with his hands. Fortunately it's the only time in Galaxy where being crushed isn't a One-Hit Kill.
- Dishing Out Dirt: Summons stalagmites to impale and trap you and throws large rocks, along with his rock armor and stone hands.
- Giant Hands of Doom: Creates them during the second half of the battle.
- Megaton Punch: His giant hands allow him to do giant punches.
- Pivotal Boss: When he's in his rock armor.
- Recurring Boss: Fought once in both games, twice in both if you count the Prankster Comets.
- Tactical Suicide Boss: If he wouldn't throw black rocks, they wouldn't turn into Bomb Boos.
- Drill Mole: A mole who burrows through the ground like a drill.
- Comical Angry Face: When he Turns Red, he flashes a mouth full of grimacing fangs and bright yellow eyes at the camera.
- "Get Back Here!" Boss: He'll stagger away in confusing patterns when dazed, making hitting him a chore.
- Fast Tunnelling: Fast enough to be a Lightning Bruiser during the last stage of its fight.
- King Mook: The largest Undergrunt in both games. His japanese name also makes him out to be this for the Monty Moles.
- Majorly Awesome: He's a major, and the strongest of the Undergrunts in the game.
- Recurring Boss: Fought once in both games.
- Turns Red: For the third stage, where he chases after you much more quickly. In fact, his spiky blue helmet turns a bright reddish orange to match!
- An Ice Person: A giant, living ice crystal.
- King Mook: Of the Li'l Brrrs- the jeweled crown makes it obvious.
- Punny Name: His name is based off of historical politician Aaron Burr.
- Shockwave Stomp: No feet to speak of, but he does slam down to create waves capable of pushing you off his platform.
Undergrunts manning cannon machines in various galaxies.
- Attack Its Weak Point: The glass cockpit to the cannon, which must be ground-pounded.
- Degraded Boss: From bosses in the first Galaxy game to minor enemy in the second.
- King Mook: Visually, to the Undergrunts, but their machines make them more of a superpowered version of the elemental shooter obstacles.
- Making a Splash: A variant fires water balls that can trap Mario and carry him into hazards.
- Pivotal Boss: Due to being in a sentry cannon, they are not able to move.
- Bones Do Not Belong There: Kingfin is a boney, skeletal shark. In real life, sharks have cartilage skeletons.
- Dem Bones: A skeletal shark. Odd, given that sharks have cartilage skeletons.
- Depending on the Writer: Prima's strategy guide, his trading card and an issue of Nintendo Power call him the Bonefin.
- Flunky Boss: Summons Fishbones to attack you.
- Glowing Eyelights of Undeath: His empty sockets glow yellow with headlight beams when Mario fights him.
- "Jaws" First-Person Perspective: How it introduces itself.
- Made of Explodium: He explodes spectacularly when defeated.
- Shows Damage: Kingfin's body becomes more and more covered in dark cracks as Mario throws Koopa shells at him.
- Threatening Shark: It doesn't get more threatening than an undead shark.
- Underwater Boss Battle: Where else would you fight a shark?
Fiery Dino Piranha
- Attack Its Weak Point: Same as before, but now the attacks have to be timed for when its tail isn't on fire.
- Dinosaurs Are Dragons: This version of Dino Piranha can breathe fireballs.
- Evil Is Burning Hot: A boss who shoots fireballs on its final hit point.
- Fireballs: On its last hit point, it'll spit globes of fire that bounce around the planet.
- "Get Back Here!" Boss: Mario has to chase after it when its tail isn't on fire.
- Incendiary Exponent: Everything Dino Piranha had, with one more hit point and flames.
- Red and Black and Evil All Over: This is to be expected from a blazing boss.
- Took a Level in Badass: He's significantly more powerful then his predecessor.
- Turns Red: On its last hit point, it starts shooting fireballs.
- Underground Monkey: It's a much stronger, fiery variant of Dino Piranha.
- Attack Its Weak Point: Its glowing behind after the egg is broken.
- Eggshell Clothing: It still wears its egg as a diaper when it hatches. You break it in the fight, but Peewee Piranha somehow brings it back together.
- "Get Back Here!" Boss: Since it doesn't have a tail, its backside must be spun, and it runs much faster.
- Suspiciously Similar Substitute: Of Dino Piranha, who appears later in the game anyway.
- Adipose Rex: Much more heavyset than the typical Lakitu.
- All There in the Manual: Its name is not given in-game - inspecting the game's object data folder reveals the model name Boss Jugemnote or checking Prima Games reveals the name King Lakitu.
- Hoist by His Own Petard: The Spinies that he throws at you are what leads to his downfall.
- Idle Animation: If you leave the arena portion of his planet for long enough, he will fall asleep until you get back up there.
- King Mook: A bigger and stronger version of a Lakitu.
- Shock and Awe: His Lakitu cloud can bring down a barrage of lightning.
- Spear Counterpart: To Kamella, being a purple Koopa subspecies who throws the projectiles you need to throw back at him to defeat him.
A two-legged jumping robot fueled by a power star. It is fought in the Spin-Dig Galaxy.
- 2½D: Its battle is fought purely in a two-dimensional sidescroller fashion.
- Attack Its Weak Point: Its glass underside contains the power star that fuels it.
- Flunky Boss: It will occasionally summon Digga enemies that will burrow towards Mario.
- Goomba Stomp: It will jump side to side in an attempt to squish the player.
- Humongous Mecha: It's pretty small compared to the other mechanical bosses in the game, but still big compared to Mario.
- Suspiciously Similar Substitute: Its design, battle, name, and appearance are extremely similar to Megaleg from the first Mario Galaxy, except much smaller and with two legs instead of three.
- This Is a Drill: Digga-Leg's primary weapon is a drill on its head that spawn Diggas, which will attempt to burrow through to the other side of the planet and attack Mario. Mario must use a drill of his own to defeat it.
A serpentine dragon answering to Bowser Jr. He makes his first appearance in Bowser Jr.'s Lava Reactor, and then a fiery version of him must be fought in the Battle Belt Galaxy.
- Attack Its Weak Point: The Bellyache Bulges, round red blobs around the creature's body, that must all be destroyed for Gobblegut to be defeated.
- Flying Brick: As a cartoonish, serpentine dragon, it has no visible means of being able to fly, yet it does.
- Meaningful Name: It's a glutton named Gobblegut.
- Our Dragons Are Different: A limbless, flying serpent with the visual flair of a Chinese dragons and the bad attitude of a European one.
- Suspiciously Similar Substitute: To Dino Piranha, if only because both have the "harder fiery version" gimmick.
- Villainous Glutton: It actively eats the planet that serves as the boss arena, and Bowser Jr. is obviously hoping it will eat Mario too.
- Attack Its Weak Point: His backside, which lacks armor.
- Rolling Attack: This guy around in a similar way to the Rock Mario powerup. Guess what you use to defeat him?
- Attack Its Weak Point: His big red nose must be hit three times with a Star Spin punch to defeat him.
- Losing Your Head: It and the planet it's fought on create the image of a twisted snowman, but Sorbetti, the "head", rolls around on the "body", creating this image.
- That's No Moon: The small planetoid before the boss planet turns out to be Sorbetti himself.
A hammer-wielding mech piloted by Bowser Jr. It is fought in Bowser Jr.'s Fearsome Fleet.
- Attack Its Weak Point: Megahammer has four weakpoints: three are the large blue structures around its body, and the final is Bowser Jr.'s cockpit.
- Drop the Hammer: The mech's primary weapons are two giant hammers that create shockwaves when they hit the stage.
- Humongous Mecha: Big enough that the entirety of Jr.'s cockpit fits into his head.
- In the Back: The third blue weak-point is located on Megahammer's back.
- More Dakka: Like Megaleg before it, Megahammer is adorned with cannons that will shoot homing Bullet Bills at Mario and Yoshi.
- Motif: It somewhat resembles a Koopa Clown Car.
- Not Quite Dead: The wrecked Megahammer can be found just before fighting the Boomsday Machine, along with the Toad Brigade. If you talk to Captain Toad, he'll assure you it's broken, but the "broken" mech will still fire Bullet Bills at you.
- Pivotal Boss: Megahammer never moves from the center of the stage, and merely turns to follow your movements on the ring-like platform that surrounds it.
- Suspiciously Similar Substitute: To Megaleg, the preceding giant robot of Bowser Jr.'s defeated by its own Bullet Bills.
- Tactical Suicide Boss: If it didn't shoot Bullet Bills...
- Adipose Rex: Much larger and noticeably obese compared to her minions. To visualise this, she is nearly thirty times Mario's size (in each dimension), and the average Pupdozer is usually around ten Marios big (in each dimension).
- Bullfight Boss: One of her attacks is charging at Mario or Luigi.
- Dark Action Girl: She's a female boss.
- Evil Is Burning Hot: She's evil and can spit fireballs.
- Fat Bitch: Compared to her minions, Glamdozer is clearly obese.
- Fireballs: One of her attacks is spitting fireballs.
- Green and Mean: She's green-eyed and villainous.
- King Mook: A huge version of the Pupdozer enemy.
- Psycho Pink: She has a lot of pink and no issue fighting Mario or Luigi.
- Turns Red: After two hits, she will run faster and spit fireballs to clog up the flipping grates on the arena to prevent Mario from using them to hit her.
- Villainous Breakdown: Particularly after she Turns Red, in which she snaps.
- Feed It a Bomb: You kill him by hurling barrages of fireballs into his open mouth.
- Pivotal Boss: We never see him move around his battlefield.
- Suspiciously Similar Substitute: To Bouldergeist, being an earth-themed Pivotal Boss that gains more weapons in the last phase of the fight and is defeated by incendiary projectiles.
- Tactical Suicide Boss: He opens his mouth at times. That's your chance to attack him.
- Throw Down the Bomblet: Squizzard's final phase has him spawn bombs in his hands and throw them.
- Weak to Fire: You need a Fire Flower to kill him.
- Evil Is Burning Hot: He has a fire attack.
- King Mook: A mobile version of the barrel-residing Octopus enemies.
- Tactical Suicide Boss: Another one who insists on shooting coconuts with his fireballs.
- Tennis Boss: Made a bit more difficult by the fact that both the player and the boss are moving around an ice rink which is obstructed by lava pools from his fire attack.
- Suspiciously Similar Substitute: To King Kaliente, another Octoomba boss who shoots fireballs and coconuts and should probably just stick to the former.
- Attack Its Weak Point: Same as before, but it must be timed, as standing next to his body will hurt you, due to the flames not present on his predecessor.
- Evil Is Burning Hot: A boss who's on fire.
- Incendiary Exponent: Everything normal Gobblegut is, with an extra hit point and on fire.
- Magma Man: As it slams through the planet, it melts the rocks into lava, making the arena even more dangerous.
- Secret Boss: He's accessed by helping a Hungry Luma form his battle arena, which typically is only reserved for the game's side missions.
- Suspiciously Similar Substitute: Serves the same role as Fiery Dino Piranha did in the first game.
A huge mechanical weapon owned and operated by Bowser Jr. It is fought in Bowser Jr.'s Boom Bunker.
- Attack Its Weak Point: Like many of Bowser Jr.'s machines, it's the cockpit. The trick is getting to it.
- Bootstrapped Leitmotif: It has the "Enter Bowser Jr." theme from the first Mario Galaxy as its leitmotif.
- Energy Ball: The main weapon of the Boomsday machine is a massive cannon that shoots homing balls of electricity.
- Floating Platforms: You need to use the Cloud Mario power up to get close enough to groundpound the cockpit. A fan weapon will occasionally suck in and destroy all of the clouds that are currently on the field.
- Foreshadowing: Immediately before fighting the Boomsday Machine, you must cross a series of platforms using the Cloud Mario power up and ground pound a pillar of rocks to reveal a sling-star: the exact steps you need to take to defeat it.
- Humongous Mecha: It's so big that Mario can walk along the surface of the tank treads.
- Motif: The machine seems designed around the idea of a castle tower, with rotating bastions and a brick-like exterior.
- Pivotal Boss: Subverted. It becomes mobile once you get two hits on it.
- Ring of Fire: Three rotating fire-bars stick out of the bottom of the tower portion of the tank meant to hit Mario when hes on the ground. When the machines tank form comes out, the fire-bars becomes an aerial hazard.
- Shock and Awe: The cockpit will occasionally let out a burst of electricity as a last line of defense against ground pounds.
- Sigil Spam: Bowser Jr.'s personal logo is stamped on the front of the tank treads.
- Spikes of Villainy: Huge spikes line the front of the tank that will hurt Mario if he touches it. Spikes also line the sides of the tank treads.
- Tank Goodness: After taking damage to its cockpit twice, the machine will start to rise out of the ground to reveal gargantuan tank treads.
- Weapons That Suck: Fans are strategically placed on the sides of the tower to suck in any clouds Mario may have made trying to attack the cockpit. The trope also applies to the fans you need to use to beat it.
Hisstocrat and Queen Hisstocrat
A pair of enormous snakes in royal regalia, who summon other gigantic snakes to attack Mario and his friends. Hisstocrat is battled first, while Queen Hisstocrat appears later. They seem to take some inspiration from Orochi, the eight-headed snake of Japanese Mythology.
- Adipose Rex: They're wider around than their snake servants.
- Attack Its Weak Point: Their heads must be jumped on.
- Battle Couple: In their final rematch in the "Boss Blitz" level.
- Boss-Arena Idiocy: Their subordinate snakes are ultimately the primary method of getting up so you can attack them, and they literally offer you Super Bells on a platter. The battle would be much more difficult if said snakes didn't have plates for Mario to stand on.
- Even Evil Has Loved Ones: In the boss fight where you face them both, jumping on the head of one of them will cause the other one to look at their partner and cry.
- Flunky Boss: Calling out their subordinate snakes are one of their methods of attack.
- Pink Girl, Blue Boy: The King is blue, and the Queen is pink.
- Psycho Pink: Queen Hisstocrat is a pink villainess.
- Reptiles Are Abhorrent: They're evil snakes.
- Requisite Royal Regalia: Both royals wear fancy crowns 24/7.
A gigantic Brolder composed of rock, crystal, and magma.
- Bad Boss: Perfectly willing to run over the Brolders he summons.
- Degraded Boss: When you fight him a second time in a blockade, the boss music doesn't play. The blockade isn't even named after him. Ironically though, this fight is much harder thanks to the Splorches.
- Expy: He and the Brolders look a lot like Geodude.
- Flunky Boss: Summons multiple Brolders in each phase of his attacks. They are the key to defeating him.
- King Mook: Of the Brolder enemies.
- Magma Man: Can throw burning lava shots in several of his attacks, and his arms are lava.
- Rock Monster: A gigantic boulder monster.
A large Ka-Thunk, who exists as a spiked metal square attached to a large metal frame. During battle, he will shift his position inside the frame while he tries to slam down on the player.
- Alliterative Name: Both his title, and name start with K.
- Attack Its Weak Point: Getting him to slam down face-first exposes his back, which is soft and marked with an "X"-shape.
- Audible Sharpness: This cue plays before he's about to slam down on his back, meaning you need to position yourself properly.
- Death Glare: Before the battle begins, he makes this face at you. The fact that he usually has wide eyes makes this particularly chilling.
- Face Plant: His primary method of attack.
- King Mook: A boss version of the Ka-Thunk enemy introduced in Super Mario 3D World.
- Spikes of Villainy: In this case, the spikes make him hard to attack for most of the battle.
- Suspiciously Similar Substitute: Ka-Thunk is a more strategic equivalent of the Whomp King, sharing the theme of you watching where you stand while he slams into the ground and attacking his back.
- Bullfight Boss: He can ram into you.
- Evil Is Burning Hot: Can spit fireballs besides ramming into the player(s).
- Fireballs: He can shoot fireballs at you.
- King Mook: Yet another boss version of Bullies; note that the Prince shares the 3D World re-design of his species.
- Palette Swap: His red parts are blue in his rematch.
- Red Eyes, Take Warning: He's a boss with red eyes.
- Technicolor Fire: Shoots blue fireball in his rematch.
- Acrofatic: The clown form has grotesque cartoonish proportions, and is rather round in shape, but still manages to leap high into the air in an attempt to crush Mario and co.
- Asteroids Monster: The clown is formed from and splits into small blobs, but there's a guy inside controlling it. If you choose to destroy the blobs instead of attacking, his clown form will gradually shrink as he re-forms it. However, a direct hit will destroy all of the blobs, and he'll regenerate the giant form at full size.
- Beat Them at Their Own Game: He fights with a large number of enemies, and the player is provided with Double Cherries to match it.
- Blob Monster: His minions are sentient round blobs which he summons with his scepter.
- Blowing a Raspberry: Sticks his tongue out to your character before summoning his blobs.
- Circus Synths: This clown's battle musicnote is a jazz/techno fusion... with electric guitars!
- The Dragon: He's Bowser's strongest enforcer in this game, being fought before you enter World Castle, one of the bosses fought before the final battle with Bowser, and is the last boss in Boss Blitz.
- Exotic Eye Designs: Both he and his blobs have (four-pointed) star-shaped pupils. This carries into the large clown form.
- Ground Pound: These are his weakness, for when he does a more powerful jump, his blobs split.
- Magical Clown: A Magikoopa and Koopaling-like jester who summons sentient blobs that form a giant clown around him.
- Monster Clown: The giant form is more on this side, with its Slasher Smile and comedic proportions. It encases the actual Koopa, formed from gelatinous blobs.
- Palette Swap: With every subsequent fight, both Motley's and the blobs' colors change.
- Punny Name: His name refers to the multitude of blobs which he summons and the name for a jester's costume.
- Red Eyes, Take Warning: A downplayed example, as it's a boss with one red eye.
- Shockwave Stomp: Gains this ability in his second and third battles, which makes it much harder to keep all of your clones while evading his jumps.
- Slasher Smile: The clown surrounding him.
- Standard Royal Court: Adds jesters to the mix of the Koopa Kingdom.
- Tactical Suicide Boss: Never seems to realize that the blob-splitting high jumps are what do him in.
- Villainous Harlequin: A jester Koopa that encases itself in blobs to become a giant clown.
- Zerg Rush: Once the clown form splits, all of the individual blobs will pursue the player while Motley flees.