[[folder:Main Characters]]
!!Mister Traveler/[[spoiler:Quote]]

%% Yes he's identified as that in the manual for the UsefulNotes/DSi port.
The PlayableCharacter. An amnesiac who awakes in a small cave in the depths of a strange island.
* AccidentalPervert: He can optionally find [[spoiler: Curly's panties in a hidden passage of the Colons' house]] in the Sand Zone. And no, they don't do anything.
** They have a purpose in the Plus edition: [[spoiler: They unlock Curly as a playable character]].
* AmnesiacDissonance: [[spoiler:It's eventually revealed that he was one of many robots sent from the surface to [[FinalSolution kill the Mimigas]] and claim the [[ArtifactOfDoom Demon Crown.]]]] [[spoiler: {{Subverted}} if you restore Curly's memories, when she remembers that the two of them were made to destroy the Demon Crown, so he's actually doing what he was made for after all.]]
* AmnesiacHero: He has no memory of his name or original mission at all. [[spoiler:He was really a robot sent from the surface to destroy the Demon Crown. He also never recovers his memories; Curly Brace has to tell him all this after she recovers her own memory.]]
* ArmyScout: He is revealed to be one of these by Professor Booster.
* BattleCouple: [[spoiler:He becomes this with Curly Brace in the best ending.]]
* ButNotTooForeign: Sue Sakamoto was unable to decipher [[http://vignette2.wikia.nocookie.net/c__/images/a/a1/Curly-sleep.gif/revision/latest?cb=20140204213124&path-prefix=cavestory the English text]] [[http://vignette4.wikia.nocookie.net/c__/images/c/c6/Betaquote.gif/revision/latest?cb=20140106071302&path-prefix=cavestory written on his hat.]] The impact of this is mostly LostInTranslation, since the English localizations aren't in Japanese. It's likely Mister Traveler was intended to be an American. This is further supported by [[WeaponOfChoice his main gun]], which is shown to be a [[RevolversAreJustBetter revolver]] in all of the [[http://vignette4.wikia.nocookie.net/c__/images/5/57/PolarStar.png/revision/latest?cb=20120927043623&path-prefix=cavestory official]] [[http://vignette2.wikia.nocookie.net/c__/images/6/6b/Quote.jpg/revision/latest?cb=20110107214657&path-prefix=cavestory artwork.]]
* ChildSoldiers: He doesn't appear to be any older than [[http://i.imgur.com/8CMzs.png about 14 years old.]] [[spoiler: [[SubvertedTrope In fact, he isn't even human.]] He's actually an [[RobotSoldier armed scout robot]].]]
* TheDrifter: An interesting case. His [[AmnesiacHero lack of memory]] leaves him with nowhere specific to go, and he spends his time [[WalkingTheEarth randomly drifting from one area to the next]] and [[ChronicHeroSyndrome assisting everyone he finds]]. The result is essentially a KnightErrant.
* ForceAndFinesse: Mister Traveler is [[ImpliedTrope implied]] to be the "Finesse" to Curly Brace's "Force", even though [[MoreDakka gameplay tends to contradict it]]. The [[https://s-media-cache-ak0.pinimg.com/originals/2e/4f/0d/2e4f0d1bc116d7c48b62cf77d87645e8.jpg official]] [[http://www.t-ono.net/media/k2/items/cache/cb1c367cf984f0ad2cae4fa928f517fc_XL.jpg artwork]] [[https://s-media-cache-ak0.pinimg.com/236x/10/9b/1b/109b1b5df3408eeff4ec48ae59b145d3.jpg consistently]] [[http://vignette2.wikia.nocookie.net/c__/images/6/6b/Quote.jpg/revision/latest?cb=20110107214657&path-prefix=cavestory shows]] their preferred weapons to be a [[RevolversAreJustBetter revolver]] and [[GatlingGood machine gun]], [[http://q.likesuccess.com/83/4100509-cave-story-3d-japanese-artwork-oprainfall.jpg respectively]]. It's also worth noting that Mister Traveler is TheQuietOne and Curly Brace is a GenkiGirl.
* TheGunslinger: Of the [[MoreDakka Vaporizer]] variety. Mister Traveler carries a [[WalkingArmory huge variety]] of [[BizarreAndImprobableBallistics highly improbable guns]] and [[BottomlessMagazines enough ammunition]] to obliterate a [[TankGoodness super-tank]] supported by [[ZergRush various mooks]].
* HeroicAlbino: He is stark white. [[spoiler:It's not actually skin, but probably some kind of polymer.]]
* HeroicMime: During the main game, Mister Traveler almost never says anything, but [[TheSilentBob characters often react as if he had.]] This implies that his dialogue is possibly meant to be imagined by the player. ''However,'' he does make player-selected Yes/No responses to questions, and at one point speaks a verbal password. When you're playing as Curly, [[TheQuietOne he only talks out loud]] ''[[TheQuietOne exactly once,]]'' implying instead that he normally just doesn't talk.
* HyperspaceArsenal: He can carry [[WalkingArmory vast amounts of weaponry]].
* LightningBruiser: Very nimble ([[spoiler:especially with the Booster upgrades]]), wields plenty of powerful weapons, and can potentially survive a lot of damage with sufficient Health upgrades.
* NiceHat: A baseball cap.
* NoNameGiven: He's only referred to as [[EveryoneCallsHimBarkeep Mister Traveler]] in official media, and only because Chako asks him if he is a traveler. [[spoiler:[[SubvertedTrope his name is]] "[[OnlyOneName Quote.]]" It's said only once in the whole game when Curly recovers her memories (or, if you're playing in Curly Mode, [[TheQuietOne the only line he says out loud)]].]]
* TheQuietOne: During the main game, Mister Traveler almost never says anything, but [[TheSilentBob characters often react as if he had]], implying that dialogue is possibly meant to be imagined by the player. ''However,'' he does make player-selected Yes/No responses to questions, and at one point speaks a verbal password. When you're playing as Curly, he only talks out loud '' exactly once,'' implying that he normally just doesn't talk.
* RedAndBlackAndEvilAllOver: With that red hat and black shirt, you start off with everyone thinking you are [[spoiler:a [[MechanicalMonster battle robot from the surface]] sent to [[FinalSolution kill the Mimigas]]. The fact that [[TomatoInTheMirror you ''are'' a robot soldier,]] (and [[EvilAlbino stark white]]) doesn't help.]] [[spoiler:Subverted later on when you learn that you were sent to destroy the Demon Crown rather than the Mimigas.]]
* RidiculouslyHumanRobots: [[spoiler: As we learn from Professor Booster, he is an [[ArmyScout armed scout robot]], despite his human-like limitations.]]
* RobotSoldier: Several [[NonPlayerCharacter non-player characters]] remark to Mister Traveler that he is a "soldier from the surface". As it turns out, all such soldiers [[TomatoInTheMirror were robots]]. Specifically, he's an [[ArmyScout armed scout robot]]. This is made jarring by [[RidiculouslyHumanRobots how amazingly human he is]].
* SavvyGuyEnergeticGirl: Mister Traveler is TheQuietOne and the official artwork seems to indicate he is on TheStoic side. Conversely, Curly is an upbeat GenkiGirl.
* ScarfOfAsskicking: He always wears a green scarf.
* SeriesMascot: Alongside [[AscendedMeme Balrog.]]
* SwordAndGun: Once the player acquires the [[CoolSword Blade]], this trope comes into play thanks to HyperspaceArsenal (since he can switch weapons instantly). Some of the official artwork [[http://vignette3.wikia.nocookie.net/c__/images/5/5f/Dsiquote.png/revision/latest?cb=20170215002954&path-prefix=cavestory deliberately invokes this]].
* ThemeNaming: [[spoiler:Quote marks " are widely used in programming software. He shares this theme with Curly Brace: Curly Braces { } are ''also'' widely used in programming software.]]
* UnusualEars: [[spoiler: His ears are RobotAntennae.]]
* WeaponOfChoice: The official artwork indicates that his favorite gun is the [[RevolversAreJustBetter Polar Star]] handgun.

!!Curly Brace
!!!Mimiga Ally
A mysterious young woman who seems to know a bit about our hero.
* ActionGirl: Justified. [[spoiler:Like Quote, she's a robot sent from the surface to destroy the Demon Crown.]]
* ArmyScout: Just like Mister Traveler.
* BadassAdorable: About as cute you can be for a [[spoiler:deadly robot]].
* BackToBackBadasses: In the Sacred Grounds, if you got the Iron Bond item, she'll ride on the main character's back, shooting things with her machine gun.
* BattleCouple: [[spoiler:She becomes this with Quote in the best ending after being a GuestStarPartyMember in an earlier battle.]]
* ChildSoldiers: She seems to be about the same age as Mister Traveler. [[spoiler: [[SubvertedTrope Just like Mister Traveler, she isn't human.]] She's actually an armed scout robot.]]
* ContractualBossImmunity: Aside from preventing drowning, her bubble tank also grants her a DeflectorShield that makes her immune to the otherwise overpowered missiles.
* DefeatMeansFriendship: The first time the player meets her, she thinks he's there to kill the Mimigas. After defeating her, she actually listens to him, and puts her weapons down.
* ForceAndFinesse: Curly Brace is [[ImpliedTrope implied]] to be the "Force" to Mister Traveler's "Finesse", even though [[MoreDakka gameplay tends to contradict it]]. The [[https://s-media-cache-ak0.pinimg.com/originals/2e/4f/0d/2e4f0d1bc116d7c48b62cf77d87645e8.jpg official]] [[http://www.t-ono.net/media/k2/items/cache/cb1c367cf984f0ad2cae4fa928f517fc_XL.jpg artwork]] [[https://s-media-cache-ak0.pinimg.com/236x/10/9b/1b/109b1b5df3408eeff4ec48ae59b145d3.jpg consistently]] [[http://vignette2.wikia.nocookie.net/c__/images/6/6b/Quote.jpg/revision/latest?cb=20110107214657&path-prefix=cavestory shows]] their preferred weapons to be a [[RevolversAreJustBetter revolver]] and [[GatlingGood machine gun]], [[http://q.likesuccess.com/83/4100509-cave-story-3d-japanese-artwork-oprainfall.jpg respectively]]. It's also worth noting that Mister Traveler is TheQuietOne and Curly Brace is a GenkiGirl.
* GameplayAllyImmortality: During the segment in the Labyrinth where she fights alongside the protagonist, she is completely invincible. She can even walk through spikes.
* GenkiGirl: Upbeat is pretty much her default mood.
* GuestStarPartyMember: During the second half of the Labyrinth.
* TheGunslinger: Just like Mister Traveler.
* HeroicSacrifice: After the battle with the Core, she gives you her bubble-tank and drowns in your place. She can be revived if you ignore the injured Booster and pick up a tow-rope in the chamber.
* LetsYouAndHimFight: Attacks the player character almost immediately after he meets her.
* LightningBruiser: Just like Mister Traveler. [[spoiler: [[JustifiedTrope she's the same sort of scout robot as Quote, and thus has exactly the same abilities as he does.]]]]
* MoreDakka: Her Machine Gun, which she'll offer to you after beating her; she takes the Polar Star in return.
* {{Nice G|uy}}irl: She and Mister Traveler have a little [[PoorCommunicationKills misunderstanding]] when they first meet but even then it was only because she was trying to protect some Mimiga kids she was taking care of. [[spoiler: She also [[HeroicSacrifice sacrifices]] herself to keep you alive for no reason other than that she wanted to.]]
* RidiculouslyHumanRobots: She can ''[[EatingMachine eat and digest food]]'', among lots of other little things.
* RobotSoldier: Just like Mister Traveler, she is an [[ArmyScout armed scout robot]].
* SavvyGuyEnergeticGirl: While Curly is an upbeat GenkiGirl, Mister Traveler is TheQuietOne and the official artwork seems to indicate he is on TheStoic side.
* SmallGirlBigGun: [[http://vignette3.wikia.nocookie.net/c__/images/c/cb/Naoku_curly.png/revision/latest?cb=20150408150216&path-prefix=cavestory Curly's gun]] seems to be [[{{BFG}} about as big as her body.]]
* SuperNotDrowningSkills: Thanks to an oxygen tank that she carries around, an oxygen bubble forms around her every time she steps foot in water. [[spoiler:She gives it to you after the Core fight.]]
* UnusualEars: [[spoiler: Just like Mister Traveler, her ears are RobotAntennae.]]
* ThemeNaming: Curly Braces { } are widely used in programming software. [[spoiler: She shares this theme with Mister Traveler, whose real name is [[OnlyOneName Quote]]: Quote marks " are ''also'' widely used in programming software.]]

!!Sue Sakamoto
!!!Looks up to her brother
A fiery young girl being pursued by the Doctor's henchmen.
* BadassBoast: Gives one before fighting Igor. She fearlessly tells him to "Bring it on!" and that she's stronger her brother. [[spoiler: However, that doesn't mean much as said brother isn't particularly strong, and unfortunately it doesn't end well for her...]]
* BalefulPolymorph: Got shapeshifted into a mimiga thanks to Misery.
* DemonicPossession: By the Doctor in the final battle. Temporary, fortunately.
* DistressedDamsel: On several occasions.
* FauxActionGirl: Just as she encounters a frenzied mimiga, she brags about how she defeated Kazuma in a fight ([[NonActionGuy which isn't saying much]]). Cue NoHoldsBarredBeatdown.
* PromotedToPlayable: The Nintendo Switch version upgrades her status to playable for a second player.
* {{Tsundere}}: First time you meet her, she gets rather annoyed if you say you wanted to save her (and annoyed if you say no), but she eventually softens.
* YouGottaHaveBlueHair: Her true hair is green.
* XMarksTheHero: Has an X-mark over her nose. [[spoiler:It's even visible in her human form.]]

The leader of the Mimiga village and Toroko's brother-figure.
* BigBrotherInstinct: He's ''very'' protective towards Toroko.
* BackupFromOtherworld: The fully upgraded Blade is less [[spoiler: Quote]] launching {{Sword Beam}}s, and more King's spirit swiping at anything he's targeting.
* CoolSword: [[spoiler:And he passes it onto your hands after taking a fatal blow from The Doctor.]]
* FaceOfAThug: He certainly ''looks'' rather sinister, but he's a case of GoodIsNotNice ''at worst''.
* GlassCannon: [[spoiler: He beats Balrog, who is a StoneWall, in a single blow. However, all it took was a single hit from The Doctor to defeat him]].
* GoodScarsEvilScars: Has a nasty scar on across his face, which adds more to his FaceOfAThug, but he's unarguably good.
* IllKillYou: Utters this to Doctor when he meets him.
* NotTooDeadToSaveTheDay: As mentioned above, the third level power for the sword is not as much throwing the sword as it is sicking King's soul at the enemy.
* RedEyesTakeWarning: Subverted in that he's a good guy regardless of this trope applying for him. [[spoiler: This is because [[WordOfGod Pixel]] confirmed that King indeed ate red flowers, but cooked them, which gave him strength but didn't turn him.]]
* SacrificialLion: Is the leader and strongest resident of the Mimiga Village, but is killed off in the Sand Zone.
* TestosteronePoisoning: Which he got from eating [[spoiler: cooked]] [[PsychoSerum red flowers.]]

!!!Misery's punching bag
A strange--if happy-go-lucky--monster under the command of the Doctor
* BaitAndSwitchBoss: After turning the power on in the Bushlands, the robot Malco prepares to attack you. Then Balrog shows up and crushes him, commencing a boss fight.
* {{Bewitched Amphibian|s}}: On the third encounter with him, he gets transformed by Misery into [[AttackOfTheFiftyFootWhatever Balfrog]].
* BoisterousBruiser: Big time.
* BullfightBoss: During the first fight with him.
* TheBrute: Acts as this towards the Doctor.
* CatchPhrase: ''Huzzah!'' (or "Oh yeah!" in commercial English versions)
* TheCavalry: [[spoiler:In the good ending, when he saves Quote and Curly Brace from Ballos' Seal Chamber.]]
* DefeatMeansFriendship: [[spoiler: Eventually. After all, he doesn't even want to follow the Doctor's plans, [[ForcedIntoEvil though he has no choice.]]]]
* HeelFaceTurn: [[spoiler: In the good ending, he and Misery are freed from the Doctor's influence, which leads to Balrog pulling a BigDamnHeroes to save Quote and Curly from Ballos' Seal Chamber closing in on them.]]
* ForcedIntoEvil: He's forced to obey whoever wears the Demon Crown. [[spoiler: When freed, he quickly pulls a HeelFaceTurn.]]
* IncomingHam: ''Huzzah!''
* JustFollowingOrders: Overlaps with ForcedIntoEvil.
* LivingWeapon: He is one for whoever wears the Demon Crown.
* MacrossMissileMassacre: During the final fight with him. Quite appropriately, you get an upgrade to rocket launcher after the battle.
* NamesToRunAwayFromReallyFast: Sounds like a name worthy of DemonLordsAndArchdevils.
* PsychopathicManchild: We don't actually know how old he is, but personality-wise the disconnect between the almost child-like way he carries himself and the monstrous things he does during the story qualifies him for this trope. For one thing, [[spoiler:during the Sand Zone part of the game you can come back to Jenka's house after getting the last dog for her and find the rest of them noticeably absent and Balrog gloating about having the key to the warehouse. [[FridgeHorror This could be seen as him killing her dogs as an interrogation method to make her give him the keys.]] For another he force-feeds Toroko red flowers, basically killing her.]]
* RecurringBoss: Fought four times throughout the first half of the game.
* SkippableBoss: The first fight with Balrog can be skipped by answering "no" when he asks if you're going to fight him.
* StoneWall: He isn't particularly fast or dangerous damage-wise, but considering how often you fight him and how much punishment he can take makes him qualify.

!!!The Doctor's servant
A young witch under the command of the Doctor.
* BalefulPolymorph: Has a penchant for this. She transformed Sue and Itoh into Mimigas, and Balrog into Balfrog.
* BossBonanza: With the Doctor and [[spoiler: the Undead Core.]]
* ClaimedByTheSupernatural: When she made Ballos create the Demon Crown, he responded by forcing her to serve whoever wears it.
* TheDragon: Technically shares this role with Balrog, but she's by far the most proactive of the two.
* DemonicPossession: Is possessed by the Doctor in the final battle.
* EvenEvilHasStandards: Basically the way that she reacts when the Doctor [[spoiler: cheats death.]]
* EvilAlbino: Though she lacks the white hair.
* {{Familiar}}: She's [[IJustWantToBeFree unwillingly]] bound to the wearer of the Demon Crown.
* ForcedIntoEvil: She's forced to obey whoever wears the Demon Crown. [[spoiler: When freed, she quickly pulls a HeelFaceTurn.]]
* HeelFaceTurn: Appears to undergo one in the end, due to the Doctor betraying her. [[spoiler: In the good ending, it's revealed that she sent Balrog to rescue Quote and Curly Brace from the Seal Chamber the moment Ballos was destroyed. Due to the fact that the Demon Crown can no longer regenerate now that he's dead, she doesn't have to follow orders from anyone else, and so she underwent a real HeelFaceTurn.]]
* KarmicTransformation: For someone with a penchant for {{Baleful Polymorph}}s, it's fitting that she gets turned into a vaguely amphibious/reptilian form.
* JustFollowingOrders: Overlaps with ForcedIntoEvil.
* LaserGuidedKarma:
** [[spoiler:So the Doctor is not as dead as you thought, and is now an omnipotent {{Energy Being|s}} of pure evil? Clearly, the best course of action is to [[BullyingADragon attack him in frustration!]]]]
** The voice in the Sacred Grounds reveals that [[spoiler:she's the one who created the Demon Crown in the first place. As Balrog points out in the ending, this makes her enslavement to whoever wears it a lot less sympathetic.]]
* LivingWeapon: She is one for whoever wears the Demon Crown.
* NamesToRunAwayFromReallyFast: Her name is ''Misery'', for crying out loud.
* TheStarscream: Heavily implied to have been one for her uncle Ballos.
* UnexplainedRecovery: From her DemonicPossession, in the credits.
* VillainTeleportation: She sure loves to TeleportSpam during her boss fight.
* YouGottaHaveBlueHair: She has dark blue hair on her sprites and green hair on portraits, though later releases changed her hair in portraits to blue.

!!The Doctor (full name:[[spoiler:Dr. Fuyuhiko Date]])
!!!The power-snatching betrayer
The cruel tyrant of the island. [[spoiler:Formerly the research group's medic, he discovered the Demon Crown and went mad with power.]]
* BadassLongcoat: Downplayed. [[spoiler:After you beat the first phase of your battle against him, he loses control of his power, goes berserk, and his long lab coat gets torn apart]].
* BigBad: The primary antagonist of the story.
* BossBonanza: With Misery and [[spoiler:the Undead Core]].
* EveryoneCallsHimBarkeep: His real name is subtly revealed after defeating the Heavy Press.
* EvilGenius
* EvilIsNotAToy: [[spoiler:It looks like he gets his KarmicDeath in his boss fight this way... [[AvertedTrope then he possesses the island's Core.]]]]
* FauxAffablyEvil: He is very formal and polite, and absolutely psychotic.
* FourEyesZeroSoul
* MorallyAmbiguousDoctorate: [[spoiler: In fact, he was the medical doctor working with the research team.]]
* ScaryShinyGlasses
* SequentialBoss: The boss fight against him has three stages.
* SuperPowerMeltdown: [[EnergyBeings Pays off]] [[DrunkOnTheDarkSide in the end.]]
* TakeOverTheWorld: His ultimate goal.
* TeleportSpam: A tactic that he relies ''way'' too much on during the first phase of the boss battle against him.
* VillainTeleportation

[[folder:Important Characters]]
A Mimiga warrior, and Toroko's brother. He was killed by the Doctor.
* HundredPercentAdorationRating: All of the Mimigas think the world of him.
* PosthumousCharacter: He died before the events of the game.

!!!Nice and Courageous
A young Mimiga and Sue's friend.
* BewareTheNiceOnes: She's a sweet girl normally, but when force-fed the Red Flower, she turned into a frenzied Mimiga bigger, faster and stronger than others.
* BlushSticker: Two permanent ones.
* {{Nice G|uy}}irl: She's extremely friendly and loyal.
* RidiculouslyCuteCritter: As with all Mimigas.
* KilledOffForReal: The player is [[ShootTheDog forced to kill her.]]
* ShootTheDog: [[PlayerPunch Sadly,]] there's nothing the player can do to prevent this.
* TragicMonster: Happens due to being force-fed [[PsychoSerum demonic flowers.]]
* UncannyFamilyResemblance: To [[NumberTwo Jack,]] of all people.

!!Kazuma Sakamoto
!!!Sometimes reliable brother
Sue's older brother.
* ButtMonkey: He is mostly seen trapped in a warehouse whining, and his younger sister Sue beats the crap out of him often.
* DirtyCoward: Of all the characters, Kazuma is the most cowardly. At the beginning of the game, he's begging for help from his little sister, who is in actual danger. [[spoiler:Near the endgame, he decides to abandon the island, leaving behind his sister and the rest of his companions. Accepting his offer to go with him leads to the game's worst ending.]]
* DistressedDude: He's first met locked up inside a Bushlands shelter.
* EyesAlwaysShut: Both in his overworld sprite and portrait.
* MrFixit
* PointlessBandAid: Has one on his left cheek.
* YouGottaHaveBlueHair: Has green hair.

!!!Keeper of the Sand Zone
An old lady who lives in the Sand Zone. She has five lost puppies, and requests that the hero [[FetchQuest find them for her]].
* AllPowerfulBystander: [[spoiler: She's just as powerful as Ballos and could have killed him when he lost his mind, ending the drama before it began... but she couldn't bring herself to kill him.]]
* ChekhovsGunman: She is [[spoiler: Ballos' sister, and the one who sealed him away after he went out of control]]. She is also [[spoiler:Misery's mother]].
* MiniatureSeniorCitizens: She's the same height as the hero, who's half the height of most humans.
* RetiredBadass: [[spoiler: Again, she sealed Ballos. Assuming he was powerful back then as well, that must have required really strong magic.]]

!!!The Mimiga-like coward engineer
A cowardly engineer transformed into a Mimiga.
* BalefulPolymorph: Transformed into a Mimiga by Misery.
* CowardlyLion: Eventually overcomes his fear to help Momorin construct the escape rocket.
* MrFixit: He's an engineer.

!!Professor Booster
!!!Sue's grandfather figure
The former research party's technician.
* JetPack: He gives one to you over the course of the game.
* TheProfessor: Of course.
* RedHerringMole: Professor Booster appears as a grumpy-looking, old scientist in a white coat wearing opaque, signal red glasses. It doesn't help that the game's main antagonist throughout the story is also a doctor in a white coat. Nonetheless he never switches sides, and even stays loyal until his death in one continuity of the game, giving away an item to the protagonist with his last bit of strength that he could otherwise have used to save himself.
* ViolationOfCommonSense: There is a point where he falls and gets major injuries. Ignore him completely [[spoiler:and he will come back alive and well with an improved Booster 2.0]].

!!Momorin Sakamoto
!!!Sue's mom
The mother of Sue and Kazuma.

!! Ballos
[[spoiler: Once Jenka's kind and loving brother, now a mad sorcerer trapped in the depths of the island.]]
* AmbidextrousSprite: Averted. His eyes keep proper colors no matter what direction he faces.
* AndIMustScream: [[spoiler: His powers are beyond even his control now, and has been living a long time with that in mind.]]
* BadassLongcoat: [[spoiler: Wears one during the first phase of your battle against him, and just like the Doctor, loses it at the second phase of the battle.]]
* BossBonanza: [[spoiler: Comes right after the Heavy Press.]]
* BeingTorturedMakesYouEvil: [[spoiler: he was tortured until his massive magic reserves [[PowerIncontinence exploded]] and [[DoomedHometown destroyed the city he loved.]] [[DespairEventHorizon His mind couldn't take the strain.]] Since that moment, he's been a danger to himself and everyone else.]]
* DeathSeeker: [[spoiler: He waits for the person who can finally kill him and subdue his powers.]]
* EvilIsBurningHot
* GreaterScopeVillain: [[spoiler: While he's not directly commanding the Doctor, he created the Demon Crown, and as long as he's alive, the Demon Crown will always regenerate after being destroyed.]]
* HatePlague: [[spoiler: His rage and insanity, coupled with his out-of-control powers, causes both the Demon Crown and Demon Flowers to exist.]]
* ICannotSelfTerminate: [[spoiler: The last thing he says to you before his death is "Now kill me... or I... shall kill you!"]]
* LightningBruiser: [[spoiler: He's extremely tough, deals a lot of damage with each hit, and surprisingly fast for his size in all forms.]]
* LoadBearingBoss: Inverted. [[spoiler: His magic is what's pulling the island down after the Core has been destroyed. Killing him causes the island to stop falling. Played straight when the walls of the room you fight him in start to close together after you beat him.]]
* MadGod: Driven insane by the brutal torture his king subjected him to, he now lies within the island as his infinite powers continue to grow, waiting for someone to kill him (while he also tries to kill them). His powers have grown far out of his control and, coupled with his rage, have [[spoiler:created a number of dangerous objects around the island as well as constantly pulling the island downwards.]]
* NiceGuy: [[spoiler: Used to be one. His sincerity and unfailing devotion to helping out his fellow people are what led to his jealous king sentencing him to [[ColdBloodedTorture insanity-inducing torture]].]]
* NightmareFace: [[spoiler: His [[OneWingedAngel last form]] is a giant ball with his face on it, with the eyes and mouth [[BodyHorror open, vacant, and filled with screaming red faces]]. It only gets worse in [[HolidayMode Halloween Mode]].]]
* PhysicalGod: [[spoiler: He possesses power far beyond normal beings.]]
* SequentialBoss: [[spoiler: You face his default form, then a giant version of his head, and finally a giant ''bloody'' version of his head.]]
* ShockAndAwe: One of his attacks is to rain down lightning bolts.
* TheAgeless: [[spoiler: He ''cannot'' die naturally, instead needing someone to kill him.]]
* TrueFinalBoss: [[spoiler: You only face him at the end of the "True Ending" route.]]
* WalkingSpoiler
* WoobieDestroyerOfWorlds

!!!Rabid Mimiga who kidnapped Sue
A frenzied Mimiga. He kidnaps Sue in the Egg Corridor. It is implied he was the caretaker of the Dragon Eggs, as the 3DS version reveals the ID Card is his.
* DegradedBoss: An identical frenzied Mimiga appears on The Balcony as a slightly stronger regular enemy, jumping higher and firing off more projectiles.

!!!Machine-monster that lurks in the sand
A robotic monster that lives in the Sand Zone. Prior to its appearance, Misery was going to fight the hero. Upon noticing him about to rise from the sand, she leaves dealing with the hero to him.
* BaitAndSwitchBoss: Misery's the bait, Omega's the switch.

!!Puu Black
!!!Ghost in the clinic
A "ghost" that haunts an old clinic in the labyrinth.
* KaizoTrap: After killing him, it is still possible to take damage and even die if you touch his remaining bubbles.
* PaletteSwap: Of Balrog, for the most part. There are subtle differences between Balrog's sprite and Puu Black's.
* SpellMyNameWithAnS: His name is spelled "Pooh Black" in the Aeon Genesis FanTranslation.

!!Monster X
!!!Big boss in the labyrinth
A large "X" shaped tank that appears in the Labyrinth. Upon defeating it, the player can see who was driving it: [[spoiler:A cat.]]
* BullfightBoss
* CoresAndTurretsBoss
* CuteKitten: The cat is there purely for laughs.
* MeaningfulName: It ''is'' shaped like an X.

!!The Core[[spoiler:/Undead Core]]
!!!Heart of the island
A large, multi-segmented monster that lives in the center of the island. Its power [[spoiler:keeps the island floating in the air. If it is destroyed, the island will fall. After defeating it the first time, it's about to be destroyed, but Misery and the Doctor arrive and save it. It becomes the Undead Core and is a possible Final Boss]].
* BossBonanza: In the second fight, it comes after Misery and the Doctor.
* ClimaxBoss: The second fight. If you don't meet the qualifications for the True Ending, though it becomes the FinalBoss
* DiscOneFinalBoss: The first fight.
* FinalBoss: Its second fight is this for the Normal ending.
* LoadBearingBoss: It ''is'' [[spoiler:keeping the island floating in the sky. More specifically, it keeps Ballos's magic from making the island fall. Misery is understandably ''[[WhatTheHellHero pissed off]]'' at you when you almost [[NiceJobBreakingItHero destroy it]] for the first time.]]
* NightmareFace: Is TheFaceless during it's first battle but when [[spoiler: The Doctor possesses it]], it gains a few nasty looking faces indicating when it's vulnerable and what attack it's going to use.
* UnderwaterBossBattle: In the first fight, it can raise the water level in the chamber in an attempt to make you drown.

!!!Big fish in the island's artery
A masked fish that lurks in the Waterway.
* TheCameo: Ironhead is a character from [[VideoGame/{{Ikachan}} one of Studio Pixel's earlier games]].
* FlawlessVictory: Defeat him without getting hurt and you will get an [[CosmeticAward Alien Badge]] and [[TheCameo see a bunch of squid swim across the screen]].
* GiantSpaceFleaFromNowhere
* UnderwaterBossBattle
* UnexpectedShmupLevel: During the battle with him.

!!The Sisters
!!!Twin dragon surprise attackers
A pair of dragons that attack the hero if he decides to pick up the missile upgrade in the [[spoiler:destroyed Egg Corridor]].
* BonusBoss: The only reason to fight them is to get a rocket ammunition which is purely optional.
* DualBoss
* EmptyRoomUntilTheTrap
* SkippableBoss

!!Ma Pignon
!!!A tasty mushroom
A mischievous mushroom that lives in Mimiga Village's graveyard. He gives the hero the Mushroom Badge if he [[spoiler:saves Curly and tells him about her amnesia. The badge itself does nothing; the actual cure is Ma Pignon himself. However, he won't go down without a fight]].
* BonusBoss: [[spoiler:Required in order to get the best ending]].
* {{Jerkass}}
* LetsMeetTheMeat: The "I want to live!" kind.

!![[{{Oni}} The Red Ogre]] (a.k.a. The Red Demon)
!!!True heroes meet the...
A red monster that appears in [[spoiler:Last Cave (Hidden)]]. It's implied that this is the creature that Arthur drove away from Mimiga Village.
* BonusBoss
* ChekhovsGunman: Briefly mentioned by Jack in an optional dialogue in the Assembly Hall earlier in the game.
* GiantSpaceFleaFromNowhere: Barely averted, since he gets a optional mention. His appearance in [[spoiler:the Last Cave (Hidden)]] is rather sudden, though.
* PaletteSwap: Of the generic enemy Droll.
** The plus version takes it a step further and gives him a HeadSwap as well, making him look more like an actual demon.
* SpamAttack: Like the Drolls he throws blades, but he throws three at a time, pause, then three more, rinse and repeat.

!!Heavy Press
!!!The swollen mech
A giant Press. It appears as a boss in [[spoiler:[[BrutalBonusLevel Sacred Grounds]]]].
* BossBonanza: [[spoiler:With Ballos.]]
* KaizoTrap: Heavy Press falls through the floor after being killed. The punishment for standing underneath it when it does so is instant death. That is, unless you abuse MercyInvincibility via one of his minions.
* OneHitKill: If you don't step out of the way as it [[KaizoTrap falls through the floor after defeat]], you will die instantly.
* KingMook
* StationaryBoss

[[spoiler: A mysterious machine within the Wind Fortress that produces clones of Curly.]]
* AIBreaker: The Mooks it spawns won't attack you when you stand on the block at the very left.
* BonusBoss: Boss of the Wind Fortress.
* MookMaker: [[spoiler: Curly clones]], to be precise.[[spoiler: Naked ones, at that, which attack by grappling you]]

!!![[NumberTwo Number-Two]]
Mimiga Village's second-in-command. He guards the entryway to the graveyard.
* CharacterTic: Pointing at people. [[WhyAreYouLookingAtMeLikeThat Also staring at them.]]
* HatOfAuthority: [[http://vignette2.wikia.nocookie.net/c__/images/d/d6/JAPJack.png/revision/latest?cb=20120925103856&path-prefix=cavestory Seems to be]] a [[http://www.eurostyleinusa.com/images2/169_6964.jpg Russian styled military hat]], with a chevron.
* HypercompetentSidekick: He's surprisingly the only member of the Jack/Toroko/King trio that quite possibly didn't die during the game.
* NerdGlasses
* NiceHat
* NumberTwo: Identifies himself as such.
* WhatHappenedToTheMouse: The last time he can be seen is in a Plantation prison. He disappears completely without a word thereafter.

!!!The cowardly loner
A resident of the Bushlands. He lost his key, so he asks the hero to find it for him.
* MalevolentArchitecture: His house comes complete with a spike-trap you can fall into for no other reason than to warn players.
* OneMarioLimit: Averted.
* SchmuckBait: Said spike-trap comes with a very obvious warning.
-->Watch out! Deathtrap to your left! [[ChunkySalsaRule One touch means instant death!]]
* StealthPun: A necessary bomb ingredient, [[spoiler:charcoal]], its found in his house. He also gives a gift to the player in exchange for finding his key.

!!!The colorful Mimiga
A Mimiga who resides in the Bushlands. The fireplace in her house contains a passageway that leads to the second half of the Bushlands.
* EventFlag: To pass through the fireplace, you need a jellyfish juice. Said jellyfish juice comes from a giant jellyfish that appears only once you have tried to pass through said fireplace.
* GoodBadGirl: Unambiguously so. She's a very friendly character, and has not one reservation about [[OptionalSexualEncounter sleeping with Mister Traveler immediately after meeting him]].
* InterspeciesRomance: She can sleep with Mister Traveler. [[spoiler:[[TomatoInTheMirror Despite all appearances]], Mister Traveler is a [[RidiculouslyHumanRobots very human-like robot]]. As such, Chako sleeping with him is actually an example of [[{{Robosexual}} another trope]]. [[SherlockScan She likely already knows]].]]
* OptionalSexualEncounter: If Mister Traveler sleeps in her bed after she mentions the jellyfish juice, he will wake up with her sleeping next to him. He obtains her lipstick, which is useless outside of getting HundredPercentCompletion.
** {{Bowdlerization}}: [[spoiler: In the 3DS remake, if Mister Traveler sleeps in Chako's bed, he'll wake up to find her sleeping on the floor instead of next to him. However, he still gets her lipstick, so [[FailedASpotCheck someone was not paying full attention]].]]
* SherlockScan: [[ImpliedTrope Implied]]. She can tell that Sue Sakamoto is a human despite the fact that she was magically changed into a Mimiga. She even claims "my eyes can't be fooled".
* SpellMyNameWithAnS: Chako in the official Nicalis translation, Chaco in the Aeon Genesis fan translation.
* ThePowerOfLove: [[spoiler: After the fight with the Muscle Doctor, talking to Chako repeatedly will cause her to compare Mister Traveler with Arthur. This will cause all of the caged Mimigas to generate hearts over their heads. [[HeartsAreHealth They function as health packs,]] and they are the ''only'' way to regain health before fighting the Undead Core.]]
* YouGottaHaveBlueHair: Mimigas are white. Chako is ''purple''. It's implied to be due to dyeing.

!!!Power Supply Bot
A robot that oversees the power room in the Bushlands. He helps break Kazuma out of a house.
* MacGyvering: He can make a bomb out of charcoal, gum, and jellyfish juice.
* RoboSpeak: In the fan-translation he SPEAKS IN ALL-CAPS ALL THE TIME.
* TinCanRobot