History Characters / AdventureTimeMultiverse

!!Fanfic World

A GenderBentAlternateUniverse to Ooo, explained through fanfics made by Ice King. Occasionally, other characters will join in to show what they think their counterpart would act like. While the cast is flipped, most are not the exact same as their original in backstory or even species.

* AllThereInTheManual: The show rarely focuses on them and most of the time it's generally ADayInTheLimelight (the first episode focusing on Fionna and Cake, the second Marshall Lee, the third on Lumpy Space Prince and the fourth spreading attention across some of the supporting cast), leaving it to the comics to generally explain more about the characters (which are canon as Natasha Allegri was the one who came up with a good chunk of concepts for the characters and wrote the comics herself).
* AlternateUniverse: A rather strange case of this as they're creations of a fanfiction the Ice King made. Yet the show treats them like this anyway.
** [[spoiler:Although the ending of "Fionna and Cake and Fionna" suggests that Ice King's stories might be based on signals he receives from another universe (presumably as another side-effect of his crown). The ''Fionna and Cake'' Miniseries reveals that the "signal" was Prismo hiding the Fionna and Cake AU in Ice King's head, having been the one who actually created the universe.]]
* BreakoutCharacter: All of them! Originally, their existence was used as a one-shot TakeThat at gender-bent fanfictions. [[GoneHorriblyRight However]], this universe became so popular that it got some sequel episodes. When the first episode aired, then-writer and later showrunner Adam Muto resisted the idea of Fionna and Cake being just Fanfiction as it would box them in to a one-note joke about Ice King's obsession with Finn and Jake. [[spoiler: The introduction of Prismo and his powers in Season 5 offered the writing team a way to develop Fionna and Cake's origins along with the eventual reveal that he was the true creator of their universe, hence the mysterious ending from Season 9's "Fionna and Cake and Fionna". Ultimately, the team never had a chance to reveal this on the original show as it would have been too complicated with the limited number of episodes they had left. Eventually, Creator/HBOMax greenlit a series for them which finally revealed their true origins.]]
* DependingOnTheWriter: In-universe example, as the universe is a fanfic, various characters (Ice King, Marceline, [=LSP=], Gunther) take their turns telling their own interpretations of the Fionna world characters so they sometimes have different personalities and motives.
* DistaffCounterpart: Played pretty straight here with a good majority of the characters being a flip of their genders. Though backstories and motivations are different from their prime counterparts.

[[folder:Fionna]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/fionna_8037.png]]
[[caption-width-right:200:"A crystal sword! I'm all about swords! How did you know?"]]
->'''Voiced by:''' Madeleine Martin

Finn's GenderFlip counterpart who is considerably more level-headed than he is. She still manages to have a thirst for adventure, however.

* ActionDressRip: When she has to fight Ice Queen while wearing a ball gown. Cake [[NotWhatItLooksLike hilariously mistakes this for something else]].
* ActionGirl: She's shown to be a good fighter like her male counterpart, especially when battling Ice Queen.
* AmbiguouslyBi: Fionna is for the most part shown to be completely straight, as everyone she shows open attraction to is male. That said the first time she met Princess Bubblegum she was blushing the whole time.
* AttractiveBentGender: She's Finn's female counterpart and is pretty and curvaceous, especially compared to Finn's more blocky figure.
* BadassAdorable: She's cute as a button, but she knows how to put up a fight.
* BadassNormal: She has no powers of her own and yet she regularly beats up stronger, more powerful people with nothing but her fists and sword.
* BerserkButton: Whatever you do, ''don't harm Cake.'' Fionna ''will'' deal out heavy punishments on anyone who dares.
* CompressedHair: Somehow manages to fit all that hair into her hat, though unlike Finn, a little bit of it shows.
* CuteBruiser: She makes good use of GoodOldFisticuffs whenever she's not using her sword.
* DistaffCounterpart: To Finn. [[spoiler:InUniverse even. When Prismo was creating her universe to create something for himself for once, he realised that the basic outline he'd drawn up (framed like it was a first-draft of a story) was basically just him copying Finn and Jake. As a result, he decided to "lean into it", and copied the land of Ooo wholesale, with some alterations to the characters as a result]].
* {{Expy}}: Outside of being a female version of Finn, she is very similar in characterization to another Natasha Allegri created character, Bee from ''WesternAnimation/BeeAndPuppycat''. This is especially true in the ''Adventure Time: Fionna and Cake'' series, where Fionna's mundane world counterpart is an eccentric womanchild who has worked multiple jobs and failed to hold down all them, and lives alone with her pet cat in an apartment. She also has a close male friend, Gary, who is a baker, which mirrors Bee's relationship with Deckard.
* FlatCharacter: Her supporting cast is a lot more fleshed out than she is. The only thing that really stands out about her is that she's a female Finn. [[spoiler:The ''Fiona and Cake'' Spinoff seems to be fixing this, as said Fiona in the spinoff is ''not'' an alternative version of this Fiona, but the same being. Her universe was created by Prismo when he wanted to experiment with creating something for himself for once, and as a result, her universe is "unauthorised". Prismo attempted to hide it by hiding it within the Ice King's warped psyche, which resulted in Fiona's universe getting transformed into a mundane and boring one when Ice King was reverted back into the normal human Simon. Being the POV character for this universe, and having to deal with the fact she and everyone she loves is slated for termination merely for ''existing'', puts Fiona into a lot of focus as a result]].
* GenderedOutfit: Fionna's skirt and bunny ears are a feminized version of Finn's pants and hat.
* GenkiGirl: Like Finn, she's hyperactive and energetic, when she's not beating her enemies to a pulp.
* HairOfGoldHeartOfGold: She's heroic and innocent like her male counterpart.
* HartmanHips: has noticeably thick legs, likely in contrast to Finns thinner legs.
* HatesBaths: According to one of the official ''Fionna & Cake'' comic stiories, "Cootie Power," Fionna does not like bathing and skips it whenever she can. Her preferred method for getting clean is to wait until it rains and stand in the rain for a while. Cake even comments that Fionna bathes less than she, a cat, does.
* IdiotHero: Not as bad as Finn, though she's more impulsive than stupid.
* InterspeciesRomance: She's a human who has ShipTease with Gumball and Marshall Lee, who are a candy person and a vampire respectively.
* LettingHerHairDown: In "Bad Little Boy" and more like a hitchhiking Cake emerging from under Fionna's hood and taking it, causing her hair to come down. But given the shipping vibes of the titular song, how frustrated and bored Fionna felt with the safer Gumball, and it occurring right as Fionna's portion of the song, the effect remains the same.
* MagicSkirt: Her skirt reveals nothing despite all the action she gets into. Justified as it's really a skort. In the ''Fionna and Cake'' miniseries, [[spoiler:the altered Fionna has problems running in her iconic skirt, which Prismo finds odd because she never had problems with the skirt in his stories. He ends up giving her shorts instead.]]
* TheNoseless: Like her male counterpart Finn, she has no nose.
* MoralityPet: To Marshall Lee. Fionna's crying is enough for him to stop messing with the poor girl's head [[spoiler:after faking his death [[DudeNotFunny just to make her confess that she has feelings for him.]]]] This doesn't stop her from beating him up after he reveals his real plan, though.
* OneOfTheBoys: Seems to consider herself this; in the comics Marshall Lee mentions having a "boy's night" and she asks why they had boy's night without her.
* PintSizedPowerhouse: Fionna is strong enough to lift and hold Prince Gumball, similar to how Finn could lift up Princess Bubblegum.
%%* RetractableWeapon: The crystal sword [[spoiler:even though it's really a trap]].
* SailorSenshiSendUp: She is partially based on ''Franchise/SailorMoon''. Highlighted by the dress she wears to the ball, which is very similar to Princess Serenity's iconic dress. Also her bunny hat. (Sailor Moon's real name, Usagi, means rabbit.) It gets another ShoutOut in [[http://static.comicvine.com/uploads/scale_large/6/67663/2909186-03c.jpg this alternate cover]] from the third issue of her comic series.
* ShipSinking: The opening sequence of ''WesternAnimation/AdventureTimeFionnaAndCake'' reveals that she dated DJ Flame, with the two even kissing onscreen, until he dumped her through a text.
* SignatureHeadgear: Her bunny hat; much like Finn's bear hat, she is rarely seen without it.
* {{Tomboy}}: Ice Queen used it as an insult, but with her ZettaiRyouiki and love for a ''{{pink|MeansFeminine}}'' crystal sword she's closer to TomboyWithAGirlyStreak.
* TomboyAndGirlyGirl: The Tomboy to Cake's Girly Girl.
* {{Tsundere}}:
** The first episode shows the HeIsNotMyBoyFriend and LuminescentBlush combo.
** "Bad Little Boy" is more Type B; she likes Marshall Lee ''and'' thinks he's a jerk. [[spoiler:Also AngerBornOfWorry when she cries when she thinks he's dying yet still berates him for flirting in such a situation.]]
* WomenAreWiser: She's much less of an IdiotHero than Finn. She's still ''kind'' of an IdiotHero, but not to Finn's extent.

[[folder:Cake]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/cake_7335.png]]
[[caption-width-right:200:"Catnip! Sweet babies!"]]
->'''Voiced by:''' Roz Ryan

Jake's GenderFlip counterpart (who is a cat) and Fionna's adoptive sister. Has the same stretching powers Jake does.

* AttentionDeficitOohShiny: In the ''Fionna and Cake'' miniseries, Cake is shown to have a bit of a short attention span and is easily distracted. Justified in that she's a cat.
* BigBeautifulWoman: When she shapeshifts into a more humanoid form and dances on stage in "Bad Little Boy".
* AdaptationalJerkass: She's noticeably meaner in the miniseries. Justified as she [[spoiler:became a regular housecat after magic was drained from her universe]] and thus never had to learn manners.
* BigBrotherMentor: She's usually the one giving Fionna advice like how to get Gumball's attention.
* TheConfidant: Fionna makes a bee line to her when she wants to talk about relationship issues.
* CoolBigSis: Cake is a big sister figure to Fionna, much like Jake is like a big brother to Finn. She's also very protective of Fionna, highlighted when she thinks Prince Gumball tried to mess with Fionna.
* DefiantCaptive: Marshall Lee kidnapped her in "Bad Little Boy", but she still fought back.
* {{Deuteragonist}}: It's "Adventure Time with Fionna ''and Cake''" after all.
* DistaffCounterpart: She is a female counterpart to Jake.
* FemaleFelineMaleMutt: Given this trope, it's only natural for the male dog Jake's counterpart to be the female cat, Cake.
* FurryReminder: Cats like to bring their owners small dead animals as gifts. [[https://static.wikia.nocookie.net/adventuretimewithfinnandjake/images/1/19/Tumblr_lmyfj7adyy1qzlgkno1_1280.jpg/revision/latest?cb=20110618031410 This comic shows it's no exception with Cake bringing her sister "presents" for her birthday.]]
* InterspeciesRomance: Has a crush on Lord Monochromicorn.
* LoyalAnimalCompanion: To Fionna.
* OffModel: [[spoiler:When Prismo looks at her as a normal cat, he gives her her original shapeshifting powers and the ability to talk without the translating collar Simon gave her.]]
* RubberMan: Like Jake, she has stretching powers that could possibly rival [[ComicBook/FantasticFour Mr. Fantastic]].
* SassyBlackWoman: Hilariously. Even if she is a cat, and a mostly ''white'' one, at that.
* ShakingTheRump: Does this in "Bad Little Boy" after shape-shifting herself into a curvy figure during Marshal Lee's song.
* ShapeshifterWeapon: She's seen being used as a weapon by Fionna during the first fight with Ice Queen.
* {{Sizeshifter}}: Like Jake, Cake is capable of making herself bigger or smaller depending on the situation.
* ShipperOnDeck: Even more so for Fionna/Gumball than Jake is for Finn/Bubblegum.
* SpiderSense: When she is agitated or senses danger, her tail frizzes out.
* TomboyAndGirlyGirl: The Girly Girl to Fionna's Tomboy.
* TrademarkFavoriteFood: Catnip, because she's a cat.
* VoluntaryShapeshifting: Like Jake, she can stretch and change her body into any form she wants.

[[folder:Prince Gumball]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/prince_gumball_5013.png]]
[[caption-width-right:200:"Come, for the wowiness has only just begun!"]]
->'''Voiced by:''' Creator/NeilPatrickHarris ("Fionna and Cake", "Bad Little Boy"), Creator/KeithFerguson ("Five Short Tables"), Creator/AndrewRannells (''Adventure Time: Fionna and Cake'')

Princess Bubblegum's GenderFlip counterpart.

* AdaptationalNameChange: In the ''Adventure Time: Fionna and Cake'' series, his name [[spoiler:after magic was drained from his universe]] is "Gary Prince."
* AmazingTechnicolorPopulation: In the ''Adventure Time: Fionna and Cake'' series, [[spoiler:after magic was drained from his universe]] he notably still has pink skin despite everyone else being given more human skin tones. His pink hair is dyed, however.
* AmazonChaser: Attracted to Fionna both for her strength ''and'' beauty. [[spoiler:However this was actually Ice Queen in disguise and simply flattering Fionna into a trap, but the real deal also thinks she is 'incredible' when fighting.]]
* AmbiguouslyBi: Given that he's PB's counterpart. While he's never shown interest in boys that's most likely since the story was made when Bubblegum and Marceline were rivals before they got back together.
** In "Five Tables Short", it's revealed that Marshall Lee is one of Gumball's "regrets", though the episode doesn't clarify what was meant by this.
** A bit more emphasis is put on their relationship in the graphic novel series, and it's similarly implied that ''something'' is going on between Marshall Lee and Gumball, as the two hang out with each other with little animosity shown between them. [[https://scarlet-flowers.tumblr.com/post/168486685535/holy-shit-this-is-from-the-official-at-comics There's also the instance in the comic where Marshall Lee confronts Gumball about being invited to his party, and they have this questionable exchange]].
* AmicableExes: In the comic series, it's implied that he and Marshall Lee had a relationship in the past and are now trying to work on having a friendship, though their different personalities make it difficult.
* BelligerentSexualTension: With Marshall Lee in the graphic novels.
* BettyAndVeronica: Unlike in the main timeline, where this isn't really a thing, the Fionna and Cake universe seems to be centered entirely around shipping, with both men more clearly attracted to Fionna. Prince Gumball is the clean-cut, chivalrous NiceGuy Betty to Marshall Lee's edgy, flirty bad boy Veronica.
** Or Gumball is Archie with Marshall being the Veronica who teases people, is a responsibility-free musician, is the heir of literal hell, would be bad publicity for the kingdom, and "possibly" previously was a mistake while Fionna is Betty who helps people, makes good on promises and quests, is a known hero, would bring good publicity, and is something new. If he has the same fate as his counterpart.
* BigOlEyebrows: In comparison to other males, like Marshall Lee.
* BishieSparkle: He's occasionally shown to sparkle and is a PrettyBoy.
* CampStraight: Given that he outwardly voices attraction to Fionna at the end of "Adventure Time with Fionna and Cake," he seems to be this. Or at least Camp Bi; we don't know much of his life, but if it's anything like his female counterpart's, he may have had something with Marshall Lee.[[note]]Since their female counterparts had undergone a RelationshipUpgrade in the GrandFinale, the same ''could'' be said for the boys.[[/note]]
* DependingOnTheWriter: His relationship with Marshall Lee changes depending on the medium they appear in, as well as who is telling or writing the story. They're enemies in Ice King's stories, possibly exes in Marceline's, and good friends [[AmbiguousSituation (possibly closer)]] in Gunther's.
* DistressedDude: From what we've seen, he's usually kidnapped by the Ice Queen and rescued by Fionna.
* DyingAlone: According to "Five Short Tables", this is his greatest fear.
* GiantPoofySleeves: It's his go-to look and they're even poofier than Bubblegum's!
* HumanPopsicle: [[spoiler:Ice Queen froze him in a giant ice spike and hung him from the ceiling of his bedroom.]]
* InterspeciesRomance:
** His relation with Fionna, since he's a sapient bubblegum being and she is a human.
** Also implied with Marshall Lee, a vampire.
* LargeHam: '''"SO VERY LARGE."'''
* InseriesNickname: Marshall Lee refers to him as "Gumwad" when he's annoyed or making fun of him.
* LastNameBasis: When he is addressed by name, he is always referred to as "Prince Gumball" rather than his first name, "Bubba."
* MasculineGirlFeminineBoy: Fionna is just as badass as her male counterpart while Prince Gumball is an absolute non-combatant. Interestingly, he also seems to be this to Princess Bubblegum, preferring baking over science and seemingly completely devoid of PB's hidden badass side.
* MasterOfTheMixedMessage:
** We can never really tell whether he likes Fionna in the romantic sense or not. [[spoiler:It's somewhat confirmed in "Fionna and Cake", but it goes back to being ambiguous in "Bad Little Boy".]]
** It's revealed in the graphic novel "Adventure Time: 2017 [=SPOookTACULAR=] issue #1" that he also sends mixed signals to Marshall Lee, as he declared that he never wanted to see him again for the pranks he kept pulling on him... only to invite him to the masquerade being held the next day "out of politeness" and then make up excuses for why they shouldn't turn him away at the door. When Marshall Lee unexpectedly shows up to the party, Prince Gumball is initially happy to see him… only to get angry at him for showing up, much to Marshall Lee's surprise, prompting him to accuse Prince Gumball of "messing with his head" for inviting him to a party that he didn't want him to attend.
* MyGreatestFailure: It's not clear ''[[NoodleIncident what]]'' said failure was, but when Butterscotch Butler brings up his "regrets" the screen cuts to a momentary flashback of Marshall Lee hissing at him with an angry look on his face.
* NiceGuy: So far it doesn't look like he has [[CuteAndPsycho a hidden side]] like his counterpart. Although such a hidden side is hinted at when he allows Fionna and Cake to toss the little [[WouldHurtAChild Jelly Kinders]] around and kick them onto the ceiling, claiming that they're not alive (they are).
* {{Necromancer}}: Like his real female counterpart, he can sort of raise the dead.
* NobleMaleRoguishMale: The noble male to Marshall Lee's roguish male for Fionna's affections.
* NonActionGuy: From what we've seen, he isn't much of a fighter.
* TheNoseless: He doesn't have a nose.
* PrettyBoy: To be expected, what with him being a prince, based on the lovely Princess Bubblegum and voiced by Neil Patrick Harris.
* PunnyName: His full name is ''Bubba Gum''ball. According to WordOfGod, his first name was supposed to be "Blowpop," but that didn't push through due to copyright reasons.
* RealMenCook: Artwork by Natasha Allegri shows that he enjoys baking. Confirmed in "Bad Little Boy."
* RealMenWearPink: Being a sentient gum-being, he ''[[AmazingTechnicolorPopulation is]]'' pink, but also wears pink, likes baking, and is generally very effeminate compared to Marshall Lee. As the human Gary, he also dyes his hair pink with Fionna's help.
* SitcomArchnemesis: To Marshall Lee.
* SpearCounterpart: He is a male counterpart to Princess Bubblegum.
* SupremeChef: Unlike his female counterpart, he trades science skills for being a master baker.
* WeUsedToBeFriends: Heavily implied to be the case with Marshall Lee in their original ''Adventure Time'' series appearances.

[[folder:Marshall Lee]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/Marshall_Lee_Day_Time_3622.png]]
[[caption-width-right:200: I've got demon eyes, and they're looking right through your anatomy.]]
->'''Voiced by:''' Creator/DonaldGlover

SpearCounterpart to Marceline, the Vampire Queen.

* AdaptationRelationshipOverhaul: Marceline and Finn are friends while their counterparts seem romantic. Either Marcy just wanted to tell a romance since the princesses would like it, she had some feelings for Finn, or Marshall has no romantic feelings and was just teasing as he is prone to joking more than his counterpart.
* ADayInTheLimelight: The Fionna and Cake episode "Bad Little Boy" focuses mainly on him.
* AffablyEvil: He plays the "Bad Boy" persona well, makes no secret of his heritage, and ''will'' summon the forces of the undead on you if he has to, but is overall a JerkWithAHeartOfGold.
* AllGirlsWantBadBoys: He believes that Fionna likes him because of this.
* AmbiguouslyBi: Given that he's Marceline's counterpart. While he's never shown interest in boys in the show that's most likely since the story was made when Bubblegum and Marceline were rivals before they got back together. On the other hand, the comic series implies that there was something going on between him and Gumball in the past, [[AmicableExes but now they're trying to be friends]].
** The show also vaguely hints at a past relationship between Marshall Lee and Gumball in "Five Tables Short" by having Gumball remember Marshall Lee as one of his "regrets".
* AmicableExes: In the comic series, it's implied that he and Gumball had a relationship in the past and are now trying to work on having a friendship, though their different personalities make it difficult.
* AuthorAvatar: [[spoiler:Just like Ice Queen]] with Marceline herself narrating the fanfic in "Bad Little Boy". Almost an EvilCounterpart since he's nastier than Marceline is currently, pre-CharacterDevelopment.
* BatOutOfHell: He can turn into a bat like his counterpart Marceline as seen in "Bad Little Boy".
* BettyAndVeronica: Unlike in the main timeline, where this isn't really a thing, the Fionna and Cake universe seems to be centered entirely around shipping, with both men more clearly attracted to Fionna. Marshal Lee is the edgy, flirty bad boy Veronica to the clean-cut, chivalrous Prince Gumball's Betty.
** Or Marshall is Archie with Fionna being the Veronica who encourages his outlandish adventurous spirit and Gumball is Betty who tries to keep him in order. If he has the same fate as his counterpart.
* BelligerentSexualTension: With Gumball in the graphic novels.
%%* BlackEyesOfEvil
* TheCameo: In the first Fionna and Cake episode.
* CardCarryingVillain: As he says in his rap "I'm evil without even trying."
* CuteLittleFangs: Though it's fairly clear that his entire mouth is full of sharp teeth.
* {{Cute Monster G|irl}}uy: Similar to Marceline.
* DependingOnTheWriter: His relationship with Marshall Lee changes depending on the medium they appear in, as well as who is telling or writing the story. They're enemies in Ice King's stories, possibly exes in Marceline's, and good friends [[AmbiguousSituation (possibly closer)]] in Gunther's.
* EeriePaleSkinnedBrunette: Because he's a vampire and he can't stand the sun.
* FullNameBasis: He's always referred to by his full name.
* EvilCounterpart: Possibly to Marceline, given that he's more antagonistic than she is.
* EvilSoundsDeep: He speaks in a deep, baritone voice.
* HalfHumanHybrid: It's revealed that he's the son of a demon and the Vampire King in "Bad Little Boy".
* ImmortalImmaturity: He's over a thousand years old, like his female counterpart Marceline, but quite immature and acts like a teenage boy prone to pranking others for his own amusement, regardless of the person being pranked's feelings.
%%* HellishPupils
* JerkWithAHeartOfGold: Pushes Cake out of the way and even kidnaps her, just as an elaborate ploy to [[spoiler:fake death and get Fionna to admit her feelings for him.]] And yet, all it took was [[spoiler:Fionna crying and calling him out on it]] to get him to realize how bad he was being. He also has this personality in the comics, and in "Five Short Tables" he's shown to be genuinely concerned about Lumpy Space Prince and tried to cure him of his uncontrollable coughing.
* NobleMaleRoguishMale: The roguish male to Prince Gumball's noble male for Fionna's affections.
* OlderThanTheyLook: Like Marceline, he's a thousand years old, but he barely looks any older than Gumball.
* PrettyBoy: Oh boy, is he ever! His first appearance in "Bad Little Boy" is him hovering over Fionna and Cake's house with his hair all tousled by the rain and him flashing his best bedroom eyes at Fionna.
* PetTheDog: Marshall openly boasts about how evil and villainous he is, [[spoiler:but will stop acting mean in a second to stop Fionna from crying]].
* PunnyName: His full name sounds just like Marceline.
%%* RedEyesTakeWarning
* SitcomArchnemesis: To Gumball; they relate with insults and pastry stealing.
* SpearCounterpart: He is a male version of Marceline.
* TallDarkAndHandsome: According to the fangirls and he does fit the description of being tall, dark haired, and good-looking.
* {{Troll}}: Pastry stealing, kidnapping, and [[spoiler:faking his death]] all for his own amusement.
* VampireMonarch: He ''is'' the Vampire King, after all.
* VegetarianVampire: Like Marceline, he's mostly seen draining the red from red or pink objects like Gumball's cream puffs.
* VillainSong: Though he gets two songs in the episode, his second song (the rap complete with beatboxing skeleton {{Mook}}s) definitely qualifies.
* WeUsedToBeFriends: Heavily implied to be the case with Prince Gumball in their original ''Adventure Time'' series appearances.
* WouldHitAGirl: First kicks Fionna through the other side of the stage in a playful fight, later pushes Cake into a tree, then engages in some shapeshifter brawling with Cake.
* YouDontLookLikeYou: In the 2023 ''Fionna and Cake'' series, fans are introduced to human Marshall Lee, a black man with dark skin and medium-length dreads who looks little like his light blue-skinned, short wavy-haired Vampire form pictured above. As well, instead of a vampire bite, he has a mole on his neck. This would turn out to be the result of [[spoiler:magic being drained fron his universe]].

[[folder:Lumpy Space Prince]]
[[quoteright:203:https://static.tvtropes.org/pmwiki/pub/images/b92ee89c7f1c46c8361ea538cd87ad59.png]]
->'''Voiced by:''' Pendleton Ward, Creator/PeterSerafinowicz ("The Prince Who Wanted Everything")

The handsome, charmingly suave, and generous prince of Lumpy Space.

* AlternateCharacterInterpretation: Invoked. In Marceline's rendition of the Ice King's fanfic, [=LSPrince=] is ([[CrossDressingVoices un]][[LarynxDissonance surprisingly]]) the ''exact same character'' as [=LSPrincess=], only with a peach-fuzz mustache. Odd thing is: this is only LSP's second appearance (he first appeared in "Adventure Time with Fionna and Cake" in a non-speaking role). It wouldn't be until his 3rd appearance that gave him character development and turned him into what is essentially the exact opposite of LSP's personality.
** The actual episode reveals that Ice King also views him as virtually identical to LSP and the suave, sophisticated portrayal he gets in the episode is only because LSP ''forced'' him to alter the character.
* CharClone: He receives such an outfit from the forest animals in "The Prince Who Wanted Everything", although he ends up discarding it.
* CoolHelmet: And one that looks oddly [[Anime/MobileSuitGundam familiar]].
* CoolMask: Again one that looks oddly [[CharClone familiar]].
* LargeHam: If possible, he's an even ''bigger'' ham than his female counterpart!
* HerCodenameWasMarySue: When LSP dictates his story, he goes from the exact same person as her to a smooth-voiced, cool gentleman. This is less because ''she'' sees herself this way, and more because she was giving her counterpart all the traits of her dream guy in the case that Ice King could make him real.
* PrettyBoy: Parodied. His face frequently shifts from LSP with some peach fuzz to a classic {{Animesque}} bishonen, while retaining his lumpy purple body.
* TertiarySexualCharacteristics: Since LSP already has a gender-neutral appearance, the only difference between her and her male counterpart is the addition of a mustache.
* VocalDissonance: Somehow manages to have this for the exact opposite reasons as his female counterpart. His suave British accent fits his appearance even less than LSP's husky ValleyGirl one.

[[folder:Lord Monochromicorn]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/lord_monochromicorn.png]]
[[caption-width-right:200:•••• • -•-- [[note]]Hey![[/note]]]]

Lady Rainicorn's GenderFlip counterpart and Prince Gumball's loyal companion. Speaks only in Morse Code. In a relationship with Cake.

* AffectionateNickname: Prince Gumball sometimes calls him "Mo-Chro."
* BilingualBonus: Only talks in Morse Code. He does this by stomping and pawing at the ground.
* CoolHorse: Both him and his female and rainbow counterpart.
* DarkIsNotEvil: He looks like the mount of a BlackKnight, but he's a great guy.
* EveryoneKnowsMorse: This is his main form of communication.
* NiceGuy: He's never shown to be anything but kind and placid.
* NonHumanSidekick: To Prince Gumball.
* SpearCounterpart: He is a male version of Lady Rainicorn.
* {{Unicorn}}: Half, anyway.

[[folder:Ice Queen]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/200px-Ice_queen_811.png]]
[[caption-width-right:200: Ha! You should talk! Keeping all the babes to yourself, totally ice-blocking my game!]]
->'''Voiced by:''' Creator/GreyDeLisle

Ice King's GenderFlip, who also manages to look thirty years younger than him. Instead of the trademark crown, she wears a tiara instead.

* AbhorrentAdmirer: To Gumball.
* AmuletOfConcentratedAwesome: If she loses her tiara, she loses all her powers.
* AdaptationalBackstoryChange: According to Gunter's version of events, [[spoiler:she was a kindly person before she went mad, but she's not a variant of Simon, nor does she have a Betty equivalent; She was already magical, being a water nymph, but she went insane saving a cat from the effects of madness-inducing jewels instead of slowly being driven insane by a crown in the 20th century.]]
* AttractiveBentGender: Best example out of all the genderbent characters, as she appears taller and much younger than the actual Ice King and wears a beautiful blue gown. Justified, as not only does she exist in a fanfiction of his creation, but [[spoiler:according to Gunter she didn't go through the same decades-long process of insanity Simon did.]] It's also because Natasha Allegri, who designed her, has said that [[BeautyIsBad she finds attractive villains far more unsettling than ugly ones]].
* AuthorAvatar: To the Ice King in her first appearance.
* DirtyOldWoman: She goes after the much younger Prince Gumball, mirroring the way her male counterpart goes after young princesses.
** Lampshaded hilariously by Fionna:
--->'''Fionna:''' Ice Queen, why you always predatoring on dudes!?
* DistaffCounterpart: She's a female Ice King.
* DyingAsYourself: [[spoiler:In the comics, once she gets ahold of the soft fire the Flame Prince was holding, i negates the evil within the jewels on her tiara and brings her back to her senses before she melts away. As it's Gunther telling the story this time, it's unknown if this'll stick or not.]]
* EvilIsDeathlyCold: She has ice magic and uses it for destructive purposes when battling Fionna or trying to kidnap Prince Gumball.
* EvilOldFolks: Also like Ice King, she's an elderly villain.
* GodSaveUsFromTheQueen: Like Ice King but female.
* ForTheEvulz: Unlike Ice King, she doesn't seem to have any redeeming values and doesn't care who has to get hurt to get what she wants.
* HerCodenameWasMarySue: She's a more attractive, more competent version of the Ice King, her initial story's author.
* AnIcePerson: She has the ability to control ice much like her male counterpart, but her powers are much more offensive.
* LadyOfBlackMagic: More serious than Ice King and has much more powerful magic. She also wears a feminine and elegant blue dress.
* MakingASplash: [[spoiler:This is an extension of her true magic as a water nymph.]]
* MasterOfDisguise[=/=]LatexPerfection: [[spoiler:Her disguise as Prince Gumball was pretty much spot-on, unlike the Ice King's Bubblegum disguise.]]
* MoreDeadlyThanTheMale: Much more competent than the Ice King. Justified, as it's a fanfiction of Ice King, so he probably made her competent regardless of her gender.
* MostFanficWritersAreGirls: Just like how Ice King wrote the fanfiction she lives in, in "Five Short Tables" it's revealed she writes her ''own'' fanfiction with {{Spear Counterpart}}s [[RecursiveFanfiction of herself, Fionna and Cake]] in the form of Ice President, Flynn the Human Being, and Jacques the Raccoon.
* NeverMessWithGranny: She may be old, but that doesn't make her any less formidable in combat.
* TheNoseless: In contrast to Ice King's long, sword-like schnoz. Early concept art shows that she was going to have one, though.
* RealityWarper: At the climax, she somehow manages to turn Fionna's sword into a useless block of ice just by staring at it. This should probably be the first sign that she's actually a powerhouse created by the Ice King.
* TheReveal: [[spoiler:The comic based on the characters goes into her backstory. Unlike Ice King, she wasn't human but rather a kindly water nymph. She saved a cat from danger and it sought to repay her by entering a dangerous labyrinth to claim a jewel. She followed it and saved it from another hazard but was injured in the process. So the cat used the jewel to save her, but in the process it made her crazy. Eventually taking on the moniker as the Ice Queen and fashioning a tiara with the jewel embedded in it.]]
* ShoutOut: According to WordOfGod, her dress is supposed to resemble the dresses of the stepsisters from ''WesternAnimation/{{Cinderella}}''.
* SilverVixen: Presumably as old as the Ice King and sports the voice of an old witch, but is absolutely gorgeous.
* TrueBlueFemininity: Inverted: she's cruel, deceptive and everything but 'fair and gentle'.
* UnusualEyebrows: The counterpart to Ice King's beard.
* VillainSue: Turns out to be an in-universe example. The wake up call to this would probably be the fact that she somehow managed to turn Fionna's sword into a useless block of ice by just ''looking at it''.
* WithGreatPowerComesGreatInsanity: Since she's the gender swapped Ice King, it's safe to say [[spoiler:her tiara also drove her insane.]]
-->'''Fionna:''' ''(after knocking the tiara off Cake)'' No! [[spoiler:You might catch her crazy.]]
** [[spoiler:The comics implied that this was indeed the case. However it wasn't so much the tiara but the jewels within it that did it.]]
* WinterRoyalLady: She has the title of Ice Queen, is always seen wearing blue, and is most definitely dangerous. [[spoiler:Turns out she was born like this since she was originally a water nymph.]]
* OlderThanTheyLook: The Ice Queen looks like a reasonably attractive middle-aged woman but is actually much older.

[[folder:Ice King]]
->''See Characters/AdventureTimeMain''
At the beginning of "Bad Little Boy", Ice King [[SelfInsertFic writes himself]] as a major MartyStu in his latest Fionna and Cake story.
[[/folder]]

[[folder:Gunter]]
->''See Characters/AdventureTimeSecondary''
In the same fanfic, Ice King's loyal servant Gunter appears as Fionna and Cake's mount. Here, he/she/it's now [[AttackOfTheFiftyFootWhatever fifty feet tall]] and shoots [[EnergyWeapon Frickin' Laser Beams]].
[[/folder]]

[[folder:Lady Lemongrabs]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/lady-lemongrabs_6839.png]]
->'''Voiced by:''' Creator/JinkxMonsoon and Creator/CreeSummer (''Adventure Time: Fionna and Cake'')

The genderbent counterparts to the Lemongrabs. They are quite similar to the originals, but are noticeably sexier... Well, slightly. The two debuted in the third issue of the Fionna and Cake comics, in the 2-page ministory "Sour Candy" by Kate Leth.

* AbusiveParents: While not outright abusive, Lady Lemongrab isn't the most... competent mother. She frequently yells harshly at her children when making simple requests or statements, and even tied up one of them in ribbon, even as the little thing wiggles in protest. Throughout their debut comic, the lemon children seem very unhappy, and their moms are oblivious to this.
* AlliterativeName: Rather than referring to themselves as countesses, they call themselves "Lady Lemongrabs."
* AllLesbiansWantKids: Being {{psycho lesbian}}s certainly didn't stop the Lady Lemongrabs from wanting to have children - or succeeding in their reproductive efforts!
* AmbiguouslyGay: Averted. The author confirmed on her Tumblr that the characters are homosexuals.
* AttractiveBentGender: Kinda subtle. The Lady Lemongrabs don't look much different from the originals aside from the obligatory and silly tertiary sexual characteristics. But they ''do'' appear to each have two butt cheeks (visible because they wear very tight pants,) unlike the original one-cheeked Lemongrabs.
* AuthorAppeal: Possibly the reason that the Lady Lemongrabs wear eyeshadow, mascara, blush, and lipstick. The author of their first comic loves makeup, and frequently posts makeup tutorials on her Kate Or Die website and Tumblr.
* BigScrewedUpFamily: Moreso than their male counterparts. Their kids don't seem as happy with their strange endeavors.
* ButNotTooGay: To promote "Sour Candy," Kate Leth made a drawing that she described as "homoerotic." She then followed this up by explitily stating that the comic itself was ''not'' that homoerotic. Also overlap with HideYourLesbians, because the lesbian aspects of these characters is significantly toned down in "Sour Candy."
%%* CloudCuckooLander:
* ColorCodedCharacters: The color schemes of their outfits are black, grey, and white, and reversed for them. Lady Lemongrab 1 seems to be the one wearing the white shirt.
* CuteMute: Their lemon children. The little ones seem to communicate through simple gestures, and facial expressions- in addition to speech bubbles containing vague symbols. This could be due to their very young age, though.
* DysfunctionalFamily: They have one. Just look at how sad their kids look throughout "Sour Candy."
* EverythingsSparklyWithJewelry: They have jewels on the front of their blouses, and sometimes on their belts.
* TheFashionista: Unlike their [[ModestRoyalty male counterparts]], who wear very simple jumpsuits, the Lady Lemongrabs wear puffy-sleeved blouses with yellow jewels on the front, long gloves, stylish belts, and taller boots, in addition to makeup. They also appear to have a variety of costumes.
* FeminineWomenCanCook: Hilariously averted- the cake that Lady Lemongrab makes is horrible.
* FictionalHoliday: "Happiest Lemon Day" is a holiday created by the Lady Lemongrabs to celebrate... something?
* FlippingTheTable: Lady Lemongrab does this to a couch, while shrieking "NYAH!"
%%* FrillsOfJustice:
* GagNose: Kate Leth didn't shy away from giving the Lady Lemongrabs the same long, pointy noses for which the original Lemongrabs are so well-known.
%%* GenkiGirl:
* GiantPoofySleeves: Both Lady Lemongrabs have these.
* HartmanHips: They have rather wide hips.
* HoldingHands: In [[http://kateordie.tumblr.com/post/48824492986/another-mini-print-for-tcaf-its-bedtime-i-am this]] print by "Sour Candy" creator Kate Leth.
* HomosexualReproduction: Like their male counterparts, the Lady Lemongrabs found a way to make themselves children. Unlike the males, we're not sure how they managed to do this.
* HulkSpeak: Sometimes does this when she gets very emotional.
* HystericalWoman: Like the counterparts they are given to drama and shouting.
* LargeHam: Of course. Just watch Lady Lemongrab frantically/psychotically making a cake and decorating the castle.
* LethalChef:
** The cake that Lady Lemongrab makes contains mold, slime, dead bugs, possibly a rat, and a sharpened pencil.
** This aspect may have been included to make her a foil to Prince Gumball, a skilled baker, as Earl of Lemongrab is a foil to the genius scientist Princess Bubblegum by being an irresponsible scientist and a ditz.
* LipstickLesbian: Kate Leth wrote the two Lady Lemongrabs to be a couple. They are also extremely feminine and even wear lipstick. As seen in the hand-holding illustration above, however, they don't always wear lipstick.
* MadScientistsBeautifulDaughter: Partial aversion. Prince Gumball seems to fairly mild-mannered and sane- it's his ''daughters'' who are the crazy ones. They're still quite attractive, though.
* MaleGaze: (Not just for the male readers, though.) This is pretty much the only reason why Kate Leth gave the Lady Lemongrabs skin-tight pants that show off their butt cheeks, and making them turn around to give the reader a nice look.
* ModestRoyalty: Downplayed. Like the Lemongrabs, they don't wear any visual indicators of their royal titles. However, they are noticeably fancier than the Lemongrabs, and more flamboyant in their dress.
* NightmareFetishist: They appear to have buckets of slime and dead animals, among other things, in their basement. Which Lady Lemongrab eventually bakes into a cake.
* NoIndoorVoice: Of course, just like the original Lemongrabs. "LEMON CHILD! WHERE DO WE KEEP THE FUN SUPPLIES?!"
* PaintedOnPants: Both wear extremely tight pants that give the viewer a good look at their butt cheeks.
* PsychoLesbian: Literally. It's been confirmed that lemon people, by nature, are prone to clinical insanity.
%%* ScreamingWoman:
%%* SensualSpandex:
* SeriousBusiness: For them, ''everything'' is serious business.
* SuperStrength: Lady LG flipped a ''couch'' without much effort.
* TertiarySexualCharacteristics: The Lady Lemongrabs are nearly identical to the original Lemongrabs. Aside from breasts, the only major differences are their outfits and makeup.

[[folder:Dr. Prince]]
[[quoteright:281:https://static.tvtropes.org/pmwiki/pub/images/s5e11_dr_prince.png]]
->'''Voiced by:''' Creator/TomKenny

Dr. Princess' GenderFlip counterpart. A villain in one of Ice King's stories.

* AdaptationalVillainy: Doctor Princess is a good-aligned character, but here he's apparently a villain for some reason.

[[folder:BMO]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/bmo_7.png]]

->''See Characters/AdventureTimeMain''
In two non-speaking appearances, BMO looks exactly the same as the "non-fictional" BMO. This may be because BMO doesn't actually have a defined gender to flip.
[[/folder]]

[[folder:Flame Prince]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/flame-prince_2195.png]]
->'''Voiced by:''' Creator/HannibalBuress

The GenderFlip of Flame Princess.

* AmbiguouslyBi: Although some artwork depict him as potential new interest for Fionna, [[spoiler:but in "Five Short Tables", he seems to have a crush or has feeling towards Turtle Prince.]]
* ElementalHairColors: His hair is red and spiked-up to go with his nature as a fire elemental.
* InvoluntaryShapeshifter: Turns into a little ball of flame when his temperature decreases too much. He can be touched in this form without injury.
* MirrorSelf: Unlike Flame Princess, he's totally good and innocent from the start, thanks to being raised by animals instead of being kept as a prisoner in a DecadentCourt.
* MrFanservice: The first time we see him, he's only wearing a loincloth.
* RaisedByWolves: Flame Prince was raised by his fire lion pride.
* ShipTease: Fionna and [[spoiler:Turtle Prince]].
* WildChild: Although he is not socially maladjusted, just unable to speak the common language. Since he was raised by fire lions, he can speak cat. Cake says he has a really heavy accent.

[[folder:Mr. Stumps]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/male_tree_trunks.png]]

The GenderFlip of Tree Trunks, as seen in the story "A Penny Burned" from the comic one-shot ''Adventure Time 2013 Summer Spectacular''.
----
* TertiarySexualCharacteristics: Resembles Tree Trunks, but has a mustache to indicate he is a guy.
[[/folder]]

[[folder:Butterscotch Butler]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/butterscotch_butler.png]]
->'''Voiced by:''' Elle Newlands

A Scottish butterscotch butler. The gender-swapped version of Peppermint Butler.

* BraveScot: She has a Scottish accent, and if she's anything like Pep-But is a force to be reckoned with. She's certainly a fierce and ruthless opponent when it comes to board games, according to "Five Short Tables".
* DepartmentOfRedundancyDepartment: When Gumball calls her, he calls her "Butterscotch Buttler, the butterscotch Scottish butler."
* PunnyName: Butter''scot''ch Butler has a Scottish accent.

[[folder:Turtle Prince]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/turtle_prince_offical.png]]
->'''Voiced by:''' Creator/CrispinFreeman

The GenderFlip of Turtle Princess.
----
* EightiesHair: His glam metal hairstyle sets him apart from his female counterpart.
* AmbiguouslyGay: [[spoiler:Unlike his female counterpart, he seems to be interested in Flame Prince rather than the opposite gender.]]
* {{Bookworm}}: Like Turtle Princess, he likes books.
* ShipTease: [[spoiler:"Five Short Tables" hints toward him and Flame Prince becoming a couple.]]

[[folder:Other fanfic characters]]
Not only does Fionna and Cake take place in a gender-swapped fanfic universe, but they also write about a gender-swapped fanfic universe of themselves. [[RecursiveFanfiction Who write a gender-swapped fanfic universe of themselves.]]

!!Flynn The Human Being
[[quoteright:265:https://static.tvtropes.org/pmwiki/pub/images/flynn_the_human.png]]
* {{Foil}}: He is this to Fionna. They are both heroic adventurers and fight off an evil wizard that has plans for their land. But while Fionna is an energetic Determinator who isnt afraid to speak her mind, Flynn is a stoic and extremely fancy FlatCharacter who has yet to get a speaking role or even a DayInTheLimelight.
* SpearCounterpart: He serves as this to Fionna.

!!Jacques The Raccoon
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/s07e35_jacques_the_raccoon.png]]
* {{Foil}}: He is this to Cake. They are both animal sidekicks to their human compatriot and help them with anything they come across. But while Cake is a sassy cat who isn't afraid to speak her mind as much as Fionna does if not more so, Jacques is a stoic and extremely fancy FlatCharacter who has yet to get a speaking role or even a DayInTheLimelight and doesn't even show off his shapeshifting powers.
* SpearCounterpart: He serves as this to Cake.

!!Ice President
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/icepresident.png]]
* {{Foil}}: He is this to the Ice Queen. They are both power-hungry BigBad Big Bads who are even more cunning than the ice King ever will. But while the Ice Queen is TheSociopath, the Ice President is more of an AntiVillain and appears to be like a third to Flynn and Jacques' partnership.
* SpearCounterpart: He serves as this to the Ice Queen.

!!Lynn the Person
[[quoteright:121:https://static.tvtropes.org/pmwiki/pub/images/lynntheperson.png]]
* FlatCharacter: She gets no characterization aside from being in a ShowWithinAShow alongside Janet.

!!Janet the Fox
[[quoteright:111:https://static.tvtropes.org/pmwiki/pub/images/janet_0.png]]
* FlatCharacter: She gets no characterization aside from being in a ShowWithinAShow alongside Lynn.

!!Mundane World

[[folder:In General]]
An average, modern Earth populated by human versions of the Fanfic universe.

* AdaptationalMundanity: Rather than fantasy creatures and magic, the world is a 1-1 recreation of 21st century Earth. Nonhuman or humanoid characters from the fanfic universe have been turned into humans here.
* AlternateUniverse: Notable in that it's an alternate take on Fionna and Cake's universe rather than the original, where the characters are normal humans and animals in a present-day setting, similar to a ModernAUFic. [[spoiler: This is because, due to being placed in Ice King's mind, Fionna and Cake's version of Ooo was stripped of its fantastical elements when Ice King was stripped of his magic and madness and returned to being Simon Petrikov.]]
* TheMagicGoesAway: [[spoiler:The world used to as magical as the fanfics portrayed it, but due to being hidden in Simon's mind, it lost its magic when Simon lost his.]]

[[folder:Fionna Campbell]]
[[quoteright:1000:https://static.tvtropes.org/pmwiki/pub/images/fac_fionna.png]]
[[caption-width-right:1000:''"I'm not really feeling like myself today..."'']]

A 29-year-old woman living in a mundane world with her pet cat Cake.

* AccidentalMurder: [[spoiler:During the events of "The Winter King" when Fionna kisses the titular character, she ends up somehow draining the magic crown he was using of its magic as he starts losing his magic and goes through RapidAging before turning to dust and dying. While it was unintentional, The Winter King was actually a BitchInSheepsClothing who transferred his madness over to that universe's version of Princess Bubblegum for a century.]]
* AffectionateNickname: Marshall Lee refers to her as "Fi" in "Fionna Campbell".
* AgeLift: Downplayed. This Fionna is much older than her fanfic counterpart. However, like the fanfic version, she is still only a little older relative to Finn, who would be 29 by the events of ''Fionna and Cake''. [[spoiler:Being ''the same being'' as her "fanfic" self, it makes sense that she aged up as well, given the length of time that's passed by the time ''Fionna and Cake'' happens]].
* AmbiguouslyBi: Besides dating the male DJ Flame, falling in love with Ice Prince in one of her dreams, [[spoiler: and kissing the Winter King]], in "The Winter King" Fionna blushes when Princess Bubblegum touches her shoulder and kisses her on the cheek.
* AntiMagic: [[spoiler:Fionna possesses the ability to remove the magic from magical beings. Just like how Cake turned a Hot Dog Knight into a regular hot dog, her kiss with the Winter King destroyed the magic of the Ice Crown and the Winter King with it. It's implied that this is not only due to her being from an "unregistered" universe, but the fact that her world had its magic removed when Simon finally had his crown removed.]]
* BloodKnight: In "The Winter King", she becomes a little ''too'' excited at the prospect of finally being able to fight and brutally slaughters every antagonistic candy citizen who crosses her path. [[spoiler: However, she regrets her actions at the end of the episode when it is revealed that they were all innocents brainwashed by the Winter King]].
* {{Expy}}: Outside of being a female version of Finn, she is very similar in characterization to another Natasha Allegri created character, Bee from ''WesternAnimation/BeeAndPuppycat'', as in the mundane world, she is an eccentric womanchild who has worked multiple jobs and failed to hold down all them, and lives alone with her pet cat in an apartment. She also has a close male friend, Gary, who is a baker, which mirrors Bee's relationship with Deckard.
* FlippingTheBird: She gives the British version of it to her boss after being fired.
* GeorgeJetsonJobSecurity: She's held multiple jobs and is unable to keep any of them. Her most recent job was being a tourist guide on a bus, which she gets fired from in the first episode of the spinoff.
* MyGodWhatHaveIDone: [[spoiler:After slaughtering all of the Candy Queen's subjects to save the Winter King and accidentally killing him too, Fionna learns that the Candy Queen and her subjects were victims of the Winter King transferring his madness to Princess Bubblegum for a century. When she is called a hero by Bubbelgum, Fionna states she was no hero and realizes she killed them without thinking about the situation and may have just made things worse for that universe before Simon cheers her up.]]
* NoFullNameGiven: Subverted, unlike her fanfic counterpart. Her full name is given as Fionna Campbell in the first episode.
* OneOfTheBoys: She has a tomboyish personality and all of her close friends are male.
* ProductionThrowback: She begins her story as a struggling and somewhat childish young adult who eventually becomes a hero in another dimension alongside her cat, mirroring the development of Bee in ''WesternAnimation/BeeAndPuppycat'', another series developed by Fionna's creator Natasha Allegri.
* TheReveal: [[spoiler:Despite ''seeming'' to be an alternative version of the original Fiona, "Prismo The Wishmaster" reveals that she's actually ''the same being''. Prismo created Fiona's universe because he wanted to make something for himself for once, and hid the "unauthorised" existence within Ice King's shattered mind, resulting in his fan fictions of their adventures. When Ice King was transformed back into Simon, it accidentally drained the magic out of their universe as well, resulting in Fiona's world becoming mundane and boring, and the inhabitants losing all memories of their fantastical lives]].
* SeriouslyScruffy: Her home is messy and she puts on old clothes when she goes to work, matching her stressful day-to-day life.
* ShipSinking:
** The opening sequence reveals that she dated DJ Flame until he dumped her via text message.
** Happens with Gumball/Gary and Marshall Lee as well. While she had ShipTease with both in ''WesternAnimation/AdventureTime'', episode 6 of the ''Fionna and Cake'' miniseries establishes that the two are developing feelings for each other.
* TrashOfTheTitans: Her apartment is filthy, so much so that when Gary stumbles into it, he assumes she's been robbed until Marshall Lee reassures him that this is just how she lives.
* {{Womanchild}}: She’s a 29-year-old woman and yet she’s very immature. For instance, she literally takes her pants off after being fired from her last job, just to get back at her boss. It’s implied that she lost many jobs because she refuses to take responsibility when her child-like attitude works against her. She also dreams of living magical, fantasy adventures in her boring, mundane life, not unlike a typical isekai child heroine. [[spoiler:It's actually residual memories of her time adventuring with Cake when their universe was still magical before Simon's {{Depower}} wound up draining the magic out of their world as well]].

[[folder:Cake]]

An ordinary cat living in a mundane world with her owner Fionna.
----
* AntiMagic: Her touch, like Fionna's, seems to sponge out the magic of entities. Her batting at a hot dog knight in episode three turned it into a regular, lifeless hot dog despite her doing nothing but touching him.
* HowDoIShotWeb: Cake is ''much'' worse at using her stretchy powers compared to Jake, [[spoiler:as all her memories have been wiped and she only got said powers back recently thanks to Prismo]]. Her shapeshifting tends to be visibly distorted & less coherent, not to mention her lack of control and creativity when using them. Her general inexperience often lands her in trouble that would otherwise be a [[{{Pun}} cake]]walk for Jake.
* TranslatorCollar: Simon puts one on Cake to allow her to talk. The collar also has numerous settings for different animal species, although all it does is change the sound of the voice coming out.
* UpliftedAnimal: {{Inverted}} in Cake's case [[spoiler:after her universe lost its magic, then reverted when Prismo changes her back to her original form in "Prismo the Wishmaster"]].

[[folder:Gary Prince]]
[[quoteright:1000:https://static.tvtropes.org/pmwiki/pub/images/fac_gary_prince.png]]

A barista and pastry chef working in Butterscotch Butler’s bakery. He plans to open his own pastry shop.

* AdaptationalRelationshipOverhaul: Gumball's relationship with Marshall Lee is antagonistic in ''WesternAnimation/AdventureTime'', with Gumball vaguely listing Marshall Lee as one of his "regrets," implying that the two were once friends (or more) but had that friendship ended poorly. However, in this series, the two do not meet in the mundane universe until "The Winter King", where they almost immediately hit it off and begin to develop feelings for each other. [[spoiler: Given that they're supposed to be the same characters as in ''WesternAnimation/AdventureTime'', it's unclear if this is meant to mirror how their relationship began in the previous setting before things between them went sour]].
* AdaptationalNameChange: To better fit into the mundane setting, his name was changed from "Bubba Gumball" to "Gary Prince."
* AmazingTechnicolorPopulation: Despite being Prince Gumball's human counterpart, his skin is still pink. His pink hair, on the other hand, has been dyed.
* FirstNameBasis: In contrast to Prince Gumball, who is always referred to as "Gumball" rather than his first name "Bubba," Gary is always referred to as "Gary" by Fionna.
* MeetCute: {{Downplayed|Trope}}; In the mundane universe, he and Marshall Lee hadn't met until "The Winter King", when Gary goes to Fionna's apartment to pick her up for their shopping trip and runs into Marshall Lee instead, who had been using her shower. Gary is surprised to find a "random dude" in Fionna's apartment while she is away, but she reassures him that he is a friend, and Marshall Lee decides to accompany him on his shopping trip in her place. The shopping trip plays out like a date, with the two developing feelings for each other.
* PlatonicLifePartners: Possibly with Fionna, as he claims to have known her for a long time and the two appear to be close, despite the fact that they have no romantic implications between them, unlike their fanfic counterparts.
* RealMenWearPink: {{Downplayed|Trope}} compared to Prince Gumball, but he has dyed pink hair, pink skin, and works as a barista and pastry chef in Butterscotch Butler's bakery.
* ShipTease: With Marshall Lee in "The Winter King". Marshall Lee flirts with him on their first meeting, and the rest of the episode that is focused on them is spent on a romantically-framed shopping "date" in which the flirting continues.

[[folder:Marshall Lee]]
[[quoteright:1000:https://static.tvtropes.org/pmwiki/pub/images/fac_marshall_lee.png]]

Marshall Lee's human counterpart and the self-proclaimed "world's best unknown musician."

* AdaptationalRelationshipOverhaul: Gumball's relationship with Marshall Lee is antagonistic in ''WesternAnimation/AdventureTime'', with Gumball vaguely listing Marshall Lee as one of his "regrets," implying that the two were once friends (or more) but had that friendship end poorly. However, in this series, the two do not meet in the mundane universe until "The Winter King", where they almost immediately hit it off and begin to develop feelings for each other. Marshall Lee is also nicer to Gary here, not making fun of him the way he did in the previous setting, and reassuring him whenever Gary begins to feel insecure during their interactions. [[spoiler: Given that they're supposed to be the same characters as in ''WesternAnimation/AdventureTime'', it's unclear if this is meant to mirror how their relationship began in the previous setting before things between them went sour]].
* MeetCute: {{Downplayed|Trope}}; In the mundane universe, he and Gary/Gumball hadn't met until "The Winter King", when Gary goes to Fionna's apartment to pick her up for their shopping trip and runs into Marshall Lee, who had been using her shower instead. Gary is surprised to find a "random dude" in Fionna's apartment while she is away, but she reassures him that he is a friend, and Marshall Lee decides to accompany him on his shopping trip in her place. The shopping trip plays out like a date, with the two developing feelings for each other.
* NiceJobBreakingItHero: [[spoiler: In "The Winter King", he invites the Lemoncarbs over to taste test Gary's baked goods so that he can pitch his bakery idea to them in the hopes that they will invest, not realizing that Gary wasn't actually ready to meet them just yet. When he tries to cancel, it's too late, and the meeting is a disaster, leaving Gary disheartened by the Lemoncarb's rejection. However, he does apologize for scheduling the meeting without Gary's knowledge and comforts him by listening to the stories behind his pastry creations.]]
** [[spoiler: It should be noted that while he was disheartened by the rejection, Gary also acknowledges that his perfectionist tendencies means if the meeting hadn't happened he's had been working the recipes until it was "perfect".]]
* ParentalNeglect: He's on semi-non-speaking terms with his mother, and flatly refuses to call her on Fionna's behalf to inform her that the rent for the month will be late. However, it is implied in "The Winter King" that he reluctantly called in a favor with his mother to schedule a meeting between the Lemoncarb twins and Gary.
* PlatonicLifePartners: In the mundane universe, he is close friends with Fiona, but their relationship lacks the romantic overtones that they had in his previous ''Adventure Time'' appearances.
* ShipTease: With Gary Prince in "The Winter King". Marshall Lee flirts with him on their first meeting, and the rest of the episode that is focused on them is spent on a romantically-framed shopping "date" in which the flirting continues.
* YouDontLookLikeYou: He is the human counterpart of Vampire King Marshall Lee, but he resembles him little due to his dark skin, medium-length dreadlocks, and a neck mole in place of a vampire bite, as opposed to vampire Marshall's light blue skin and short wavy hair. He also has a darker complexion than his female counterpart's human mother, who is AmbiguouslyBrown, implying that his appearance and ethnicity were influenced by his African-American voice actor Creator/DonaldGlover.

[[folder:DJ Flame]]

The mundane universe equivalent of Flame Prince. He is also Fionna's ex-boyfriend.

* AdaptationalJerkass: While he seemed like a decent guy in his original fanfic appearances, DJ Flame breaks up with Fionna via a two-word text message in the opening sequence.
* OutOfFocus: 6 episodes into the 10-episode series, he's yet to have a speaking role.

[[folder:Beatrice Buttler]]

The human counterpart of Butterscotch Butler. She is the crotchety owner of Butler’s Buttery Buns, the bakery where Gary Prince works.
----
* AdaptationalRelationshipOverhaul: She is subservient to Prince Gumball in the fanfic universe. However, in the mundane setting, she is his crotchety boss.
* AppealToTradition: She refuses to allow Gary to sell his own baked goods because she believes her traditional buttery buns are superior without even trying his work. She also allows mice to roam around her bakery because it is supposedly customary.
* MeanBoss: To prove that her traditional buttery buns are superior to Gary's pastries, rather than tasting it, she drops one on the floor and lets a mouse decide which one it prefers. She also repeatedly pokes Gary in the torso to emphasize her point about "traditional" being better.
* TheNapoleon: She wears platform heels to make herself appear taller than she actually is and has quite the attitude, especially toward Gary Prince.

[[folder:Ellis P]]
The human counterpart of Lumpy Space Prince. A self-proclaimed miracle worker who is friends with Marshall.

[[folder:Lemoncarb Twins]]

The human counterparts of the Lady Lemongrabs. They are a pair of wealthy sisters known for running a food empire and making businesses flourish with their investments.

* AdaptationSpeciesChange: Their equivalent to Lemon Camel is a yellow dog with a similarly droopy face.
* JabbaTableManners: They messily eat away at Gary's pastry mansion, considering its taste okay but disliking the cute figures.
* {{Jerkass}}: They demean Gary's pastry mansion at almost every step of his interview with them and vandalize the doorway as they leave.
* TruerToTheText: The Lemoncarbs match their original counterparts closer than their fanfic selves. The two are portrayed as sisters rather than an unrelated couple, and unlike the Lady Lemongrabs' more flamboyant style, they wear plain shirts and yoga pants resembling the earls' jumpsuits.

!!Winter King World
[[folder:In General]]
A snowy wonderland where the kindly Winter King is menaced by the Candy Queen. However, not all is well underneath the land's glittery surface.

* RoleSwapAU: In this world, it's the crazed leader of the Candy Kingdom harassing the Winter Kingdom rather than the other way around. [[spoiler:This is because the Winter King redirected the madness of the crown to Princess Bubblegum, leaving her with the same instability Ice King would normally have.]]

[[folder:The Winter King]]
->'''Voiced by:''' Creator/BrianDavidGilbert

An alternate sane and handsome version of the Ice King who's a beloved leader terrorized by the deranged Candy Queen.

* AlternateUniverseReedRichardsIsAwesome: He's the Ice King if he was smart, handsome and retained his sanity that the Crown took away, using his powers for good and opposing an insane evil version of PB. [[spoiler:However, he once was like the main universe Ice King and managed to make himself into the "awesome" version by cursing PB to be driven to insanity by transferring the Crown's madness to her without the princess' consent.]]
* BitchInSheepsClothing: He's handsome, sane and all-around a friendly guy to Fionna, Cake and Simon; and greatly opposes the Candy Queen who is essentially a role-swapped insane Princess Bubblegum... [[spoiler:Except he's responsible for everything wrong in the first place as he passed the insanity of the Crown's power to Bubblegum and had no remorse about how it affected her and her subjects for over a century.]]
* EvilCounterpart: The Winter King is initially introduced as a version of Simon who appears to have overcome the madness of the Ice Crown while keeping his powers and appears to have made a thriving Winter Kingdom while being constantly kidnapped by that universe's version of Princess Bubblegum, the insane Candy Queen, and her monstrous subjects. [[spoiler:In reality however, he never actually overcame the madness, he instead transferred it to Princess Bubblegum and made her insane instead while refusing to try and reason with her when she was in that state while waiting for someone to rescue him all to hide his darker personality traits. The Winter King also doesn't seem to show no care when reminded of Betty and tells Simon that he could just make an Ice Betty in her place with the Ice Marceline in the Kingdom implying that he did it before after something happened to the Marceline of his universe.]]
* NoImmortalInertia: [[spoiler:The Winter King admits that he conquered the crown well over one hundred years ago, kept young and strong by its magic. Naturally, when Fionna's kiss accidentally removes that magic, the Winter King undergoes RapidAging and dissolves into dust.]]
* OOCIsSeriousBusiness: When Simon asks about his universe's version of Betty he is dismissive of her and rudely calls her "the dead one", which serves as one of the first hints that [[spoiler:the Winter King is still affected by the crown's influence under his MaskOfSanity.]]
* ScrewYourself: According to him, he's thought of kissing an alternate version of himself for a while, or probably as soon as he met the main timeline Simon.
* ShipTease: Fionna develops a crush on him and the Winter King seems to reciprocate, even reaching for a kiss when she wants one. [[spoiler:Too bad for them that Fionna somehow makes the Crown lose its magic and hold over this Simon, causing him to quickly age into dust.]]
* VocalDissonance: Unlike alternate universe versions of other characters The Winter King has a different voice from Simon and Ice King. [[spoiler:After Fionna glitches the crown his voice reverts, implying that he had been altering his voice with magic.]]

[[folder:The Candy Queen]]
->'''Voiced by:''' Creator/HyndenWalch

An alternate insane and monstrous version of Princess Bubblegum who terrorizes and kidnaps the Winter King on a regular basis.

* TheAssimilator: She plans to throw herself, Simon, and the Winter King into a blender to forcibly fuse their bodies together.
* EvilCounterpart: Is introduced as a crazy evil version of Princess Bubblegum, [[spoiler:except she's only like that because the Winter King transferred his madness to her.]]
* EvilMakesYouMonstrous: The Candy Queen, the equivalent of Princess Bubblegum, is evil, and as a result, has a more monstrous and inhuman appearance. [[spoiler:When the curse is lifted, it turns out the Candy Queen ''is'' Princess Bubblegum, and reverts back to her normal appearance.]]
* FoodBasedSuperpowers: Like the OG Bubblegum, she has control over candy, to a much greater degree than the science minded one ever had.
* StalkerWithACrush: She repeatedly kidnaps the Winter King to make him love her.
* UncannyValley: She is drawn with large eyes, brightly colored irises, and [[EmptyEyes no pupils]] in contrast to the show's [[BlackBeadEyes usual art style]], which serves to make her even more unnerving [[spoiler:and foreshadows that she was secretly brainwashed the whole time]].

!!Fanfic World

[[folder:In General]]
A GenderBentAlternateUniverse to Ooo, explained through fanfics made by Ice King. Occasionally, other characters will join in to show what they think their counterpart would act like. While the cast is flipped, most are not the exact same as their original in backstory or even species.

* AllThereInTheManual: The show rarely focuses on them and most of the time it's generally ADayInTheLimelight (the first episode focusing on Fionna and Cake, the second Marshall Lee, the third on Lumpy Space Prince and the fourth spreading attention across some of the supporting cast), leaving it to the comics to generally explain more about the characters (which are canon as Natasha Allegri was the one who came up with a good chunk of concepts for the characters and wrote the comics herself).
* AlternateUniverse: A rather strange case of this as they're creations of a fanfiction the Ice King made. Yet the show treats them like this anyway.
** [[spoiler:Although the ending of "Fionna and Cake and Fionna" suggests that Ice King's stories might be based on signals he receives from another universe (presumably as another side-effect of his crown). The ''Fionna and Cake'' Miniseries reveals that the "signal" was Prismo hiding the Fionna and Cake AU in Ice King's head, having been the one who actually created the universe.]]
* BreakoutCharacter: All of them! Originally, their existence was used as a one-shot TakeThat at gender-bent fanfictions. [[GoneHorriblyRight However]], this universe became so popular that it got some sequel episodes. When the first episode aired, then-writer and later showrunner Adam Muto resisted the idea of Fionna and Cake being just Fanfiction as it would box them in to a one-note joke about Ice King's obsession with Finn and Jake. [[spoiler: The introduction of Prismo and his powers in Season 5 offered the writing team a way to develop Fionna and Cake's origins along with the eventual reveal that he was the true creator of their universe, hence the mysterious ending from Season 9's "Fionna and Cake and Fionna". Ultimately, the team never had a chance to reveal this on the original show as it would have been too complicated with the limited number of episodes they had left. Eventually, Creator/HBOMax greenlit a series for them which finally revealed their true origins.]]
* DependingOnTheWriter: In-universe example, as the universe is a fanfic, various characters (Ice King, Marceline, [=LSP=], Gunther) take their turns telling their own interpretations of the Fionna world characters so they sometimes have different personalities and motives.
* DistaffCounterpart: Played pretty straight here with a good majority of the characters being a flip of their genders. Though backstories and motivations are different from their prime counterparts.

[[folder:Fionna]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/fionna_8037.png]]
[[caption-width-right:200:"A crystal sword! I'm all about swords! How did you know?"]]
->'''Voiced by:''' Madeleine Martin

Finn's GenderFlip counterpart who is considerably more level-headed than he is. She still manages to have a thirst for adventure, however.

The off-kilter leader of the Destiny Gang, a group of criminals in Farmworld.

Finn's counterpart in the "Farmworld" universe.

Marceline's counterpart in the "Farmworld" universe.

Ice King's counterpart in the "Farmworld" universe.

Choose Goose's counterpart in the "Farmworld" universe.

Finn's counterpart in the "Farmworld" universe created from a wish made to attempt to stop the Lich.

* AgeWithoutYouth: In the Farmworld alternate timeline, she lived for a thousand protecting Simon's corpse from looters, but without her vampire powers keeping her youthful she became a very elderly woman.
* CoolOldLady: In the farmverse, though she is pretty batty.
* FamilyUnfriendlyDeath: In the Farmworld, she is killed by the explosion caused by Finn's mayhem.
* LongLived: Originally; the Farmworld reveals that as a half-demon, her lifespan is well over 1000 years naturally, but without the added bonus of vampirism, her body and magic will vastly deteriorate into old age.
* TheNoseless: Like the other humanoids. Though she can [[SuddenAnatomy morph a nose]] when she wants to smell something or pick it. This carries over to the Farmworld, where she appears to be the only denizen without one.

* HeroicSacrifice: Farmworld Ice King was able to stop the bomb that would create the Lich, but in doing so was crushed underneath the frozen bomb.

* RoleSwapAU: In this world, it's the crazed leader of the Candy Kingdom harassing the Winter Kingdom rather than the other way around. [[spoiler:This is because the Winter King redirected the madness he would have contracted to Princess Bubblegum, leaving her with the same instability Ice King would normally have.]]

* SwappedRoles: In this world, it's the crazed leader of the Candy Kingdom harassing the Winter Kingdom rather than the other way around. [[spoiler:This is because the Winter King redirected the madness he would have contracted to Princess Bubblegum, leaving her with the same instability Ice King would normally have.]]

* AdaptationalMundanity: Due to initially lacking the Lich's presence, there's far less magic going around in Farmworld than Ooo. While Marceline is still half-demon, her lack of vampire powers make her age like the other humans.

* AllThereInTheManual: The TV Show rarely focuses on them and most of the time it's generally ADayInTheSpotlight (At the current there are only four episodes: The first focusing on Fionna and Cake, the second Marshall Lee, the third on Lumpy Space Prince and the fourth spreading attention across some of the supporting cast). Leaving it to the comics to generally explain more about the characters (which are canon as Natasha Allegri was the one who came up with a good chunk of concepts for the characters and wrote the comics herself).

* AdaptationalMundanity: Due to initially lacking the lich's presence, there's far less magic going around in Farmworld than Ooo. While Marceline is still half-demon, her lack of vampire powers make her age like the other humans.

** The ''Fionna and Cake'' miniseries starts in a version of the universe where the characters are normal humans and animals in a present-day setting, similar to a ModernAUFic. [[spoiler: This is because, due to being placed in Ice King's mind, Fionna and Cake's version of Ooo was stripped of its fantastical elements when Ice King was stripped of his magic and madness and returned to being Simon Petrikov.]]

* TheFashionista: Unlike their [[ModestRoyalty male counterparts]], who wear very simple jumpsuits, the Lady Lemongrabs wear puffy-sleeved blouses with yellow jewels on the front, long gloves, stylish belts, and taller boots, in addition to makeup. They also appear to have a variety of costumes. This is reversed with their human counterparts in the ''Fionna and Cake'' miniseries, whom wear plain shirts and yoga pants resembling the earls' jumpsuits.

* UncannyValley: She is drawn with large eyes, brightly colored irises, and [[EmptyEyes no pupils]] in contrast to the show's [[BlackBeadEyes usual art style]], which serves to make her even more unnerving [[spoilersspoiler:and foreshadows that she was secretly brainwashed the whole time]].

* UncannyValley: She is drawn with large eyes, brightly colored irises, and [[EmptyEyes no pupils]] in contrast to the show's [[BlackBeadEyes usual art style]], which serves to make her even more unnerving [[spoilers:and foreshadows that she was secretly brainwashed the whole time]].

An alternate insane and grosser version of Princess Bubblegum who terrorizes and kidnaps the Winter King on a regular basis.

* EvilMakesYouMonstrous: The Candy Queen, the equivalent of Princess Bubblegum, is evil, and as a result, has a much grosser and more inhuman appearance. [[spoiler:When the curse is lifted, it turns out the Candy Queen ''is'' Princess Bubblegum, and reverts back to her normal appearance.]]

* UncannyValley: She is drawn with large eyes and brightly colored visible irises in contrast to the show's [[BlackBeadEyes usual art style]], which serves to make her even more unnerving.

* UncannyValley: She is drawn with large eyes and brightly colored visible scelera in contrast to the show's [[BlackBeadEyes usual art style]], which serves to make her even more unnerving.

* AttractiveBentGender: Best example out of all the genderbent characters, as she appears taller and much younger than the actual Ice King and wears a beautiful blue gown. Justified, as [[spoiler:she exists in a fanfiction of his creation.]] It's also because [[WordOfGod Natasha Allegri]], who designed her, has said that [[BeautyIsBad she finds attractive villains far more unsettling than ugly ones]].
* AuthorAvatar: [[spoiler:To the Ice King]].

* DyingAsYourself: [[spoiler:In the comics, once she gets ahold of the soft fire the Flame Prince was holding. It negates the evil within the jewels on her tiara and brings her back to her senses before she melts away. Course as it's Gunther telling the story this time, it's unknown if this'll stick or not.]]

* HerCodenameWasMarySue: [[spoiler:She's a more attractive, more competent version of the Ice King, the story's author]].

* MoreDeadlyThanTheMale: Much more competent than the Ice King. [[spoiler:Justified, as it's a fanfiction of Ice King, so he probably made her competent regardless of her gender.]]
* MostFanficWritersAreGirls: [[spoiler:Just like how Ice King wrote the fanfiction she lives in,]] in "Five Short Tables" it's revealed she writes her ''own'' fanfiction with {{Spear Counterpart}}s [[RecursiveFanfiction of herself, Fionna and Cake]] in the form of Ice President, Flynn the Human Being, and Jacques the Raccoon.

* RealityWarper: At the climax, she somehow manages to turn Fionna's sword into a useless block of ice just by staring at it. [[spoiler:This should probably be the first sign that she's actually a powerhouse created by the Ice King]].

* AffectionateNickname: Marshall Lee refers to her as "Fi" in episode 1.

* AmbiguouslyBi: Besides dating the male DJ Flame, falling in love with Ice Prince in one of her dreams, [[spoiler: and kissing the Winter King]], in episode 6 Fionna blushes when Princess Bubblegum touches her shoulder and kisses her on the cheek.

* BloodKnight: In episode 6, she becomes a little ''too'' excited at the prospect of finally being able to fight and brutally slaughters every antagonistic candy citizen who crosses her path. [[spoiler: However, she regrets her actions at the end of the episode when it is revealed that they were all innocents brainwashed by the Winter King]].

** Happens with Gumball/Gary and Marshall Lee as well. While she had ShipTease with both in ''WesternAnimation/AdventureTime'', episode 6 of this show establishes that the two are developing feelings for each other.

* AdaptationalRelationshipOverhaul: Gumball's relationship with Marshall Lee is antagonistic in ''WesternAnimation/AdventureTime'', with Gumball vaguely listing Marshall Lee as one of his "regrets," implying that the two were once friends (or more) but had that friendship ended poorly. However, in this series, the two do not meet in the mundane universe until episode 6, where they almost immediately hit it off and begin to develop feelings for each other. [[spoiler: Given that they're supposed to be the same characters as in ''WesternAnimation/AdventureTime'', it's unclear if this is meant to mirror how their relationship began in the previous setting before things between them went sour]].

* MeetCute: {{Downplayed|Trope}}; In the mundane universe, he and Marshall Lee hadn't met until episode 6, when Gary goes to Fionna's apartment to pick her up for their shopping trip and runs into Marshall Lee instead, who had been using her shower. Gary is surprised to find a "random dude" in Fionna's apartment while she is away, but she reassures him that he is a friend, and Marshall Lee decides to accompany him on his shopping trip in her place. The shopping trip plays out like a date, with the two developing feelings for each other.

* ShipTease: With Marshall Lee in episode 6. Marshall Lee flirts with him on their first meeting, and the rest of the episode that is focused on them is spent on a romantically-framed shopping "date" in which the flirting continues.

* AdaptationalRelationshipOverhaul: Gumball's relationship with Marshall Lee is antagonistic in ''WesternAnimation/AdventureTime'', with Gumball vaguely listing Marshall Lee as one of his "regrets," implying that the two were once friends (or more) but had that friendship end poorly. However, in this series, the two do not meet in the mundane universe until episode 6, where they almost immediately hit it off and begin to develop feelings for each other. Marshall Lee is also nicer to Gary here, not making fun of him the way he did in the previous setting, and reassuring him whenever Gary begins to feel insecure during their interactions. [[spoiler: Given that they're supposed to be the same characters as in ''WesternAnimation/AdventureTime'', it's unclear if this is meant to mirror how their relationship began in the previous setting before things between them went sour]].
* MeetCute: {{Downplayed|Trope}}; In the mundane universe, he and Gary/Gumball hadn't met until episode 6, when Gary goes to Fionna's apartment to pick her up for their shopping trip and runs into Marshall Lee, who had been using her shower instead. Gary is surprised to find a "random dude" in Fionna's apartment while she is away, but she reassures him that he is a friend, and Marshall Lee decides to accompany him on his shopping trip in her place. The shopping trip plays out like a date, with the two developing feelings for each other.
* NiceJobBreakingItHero: [[spoiler: In episode 6, he invites the Lemoncarbs over to taste test Gary's baked goods so that he can pitch his bakery idea to them in the hopes that they will invest, not realizing that Gary wasn't actually ready to meet them just yet. When he tries to cancel, it's too late, and the meeting is a disaster, leaving Gary disheartened by the Lemoncarb's rejection. However, he does apologize for scheduling the meeting without Gary's knowledge and comforts him by listening to the stories behind his pastry creations.]]

* ParentalNeglect: He's on semi-non-speaking terms with his mother, and flatly refuses to call her on Fionna's behalf to inform her that the rent for the month will be late. However, it is implied in episode 6 that he reluctantly called in a favor with his mother to schedule a meeting between the Lemoncarb twins and Gary.

* ShipTease: With Gary Prince in episode 6. Marshall Lee flirts with him on their first meeting, and the rest of the episode that is focused on them is spent on a romantically-framed shopping "date" in which the flirting continues.

!!Lumpy Space Prince

!!Lord Monochromicorn

!!Ice Queen

!!Gunter

!!Lady Lemongrabs

!!Dr. Prince

!!BMO

!!Flame Prince

!!Mr. Stumps

!!Butterscotch Butler

!!Turtle Prince

->''See Characters/AdventureTimeMinor''

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/farmworld_finn_sad.png]]
[[caption-width-right:350:[[labelnote:Click here]]https://static.tvtropes.org/pmwiki/pub/images/ice_finn.png[[/labelnote]] to see Ice Finn.]]

* {{Gonk}}:

[[folder:General]]

[[quoteright:150:https://static.tvtropes.org/pmwiki/pub/images/choose_goose_5212.png]]

* AccidentalMurder: [[spoiler:During the events of "The Winter King" when Fionna kisses the titular character, she ends up somehow draining the magic crown he was using of it's magic as he starts losing his magic and goes through RapidAging before turning to dust and dying. While it was unintentional, The Winter King was actually a BitchInSheepsClothing who transferred his madness over to that universe's version of Princess Bubblegum for a century.]]

* AgeLift: Downplayed. This Fionna is much older than her fanfic counterpart. However, like the fanfic version, she is still only a little older relative to Finn, who would be 29 by the events of ''Fionna and Cake''. [[spoiler:Being ''the same being'' as her "fanfic" self, it makes sense that she aged up as well, give the length of time that's passed by the time ''Fionna and Cake'' happens]].

* MyGodWhatHaveIDone: [[spoiler:After slaughtering all of the Candy Queen's subjects to save the Winter King and accidentally killing him too, Fionna learns that the Candy Queen and her subjects were victims of the Winter King transferring his madness to Princess Bubblegum for a century. When she is called a hero by Bubbelgum, Fionna states she was no hero and realized she killed them without thinking about the situation and may have just made things worse for that universe before Simon cheers her up.]]

* TheReveal: [[spoiler:Despite ''seeming'' to be an alternative version of the original Fiona, "Prismo The Wishmaster" reveals that she's actually ''the same being''. Prismo created Fiona's universe because he wanted to make something for himself for once, and hid the "unauthorised" existence within Ice King's shattered mind, resulting in his fan fictions of their adventures. When Ice king was transformed back into Simon, it accidentally drained the magic out of their universe as well, resulting in Fiona's world becoming mundane and boring, and the inhabitants losing all memories of their fantastical lives]].

* {{Womanchild}}: She’s a 29-year-old woman and yet she’s very immature. For instance, she literally takes her pants off after being fired from her last job, just to get back at her boss. It’s implied that she lost many jobs because she refuses to take responsibilities when her child-like attitude works against her. She also dreams to live magical, fantasy adventures in her boring, mundane life, not unlike a typical isekai child heroine. [[spoiler:It's actually residual memories of her time adventuring with Cake when their universe was still magical, before Simon's {{Depower}} wound up draining the magic out of their world as well]].

* AdaptationalRelationshipOverhaul: Gumball's relationship with Marshall Lee is antagonistic in ''WesternAnimation/AdventureTime'', with Gumball vaguely listing Marshall Lee as one of his "regrets," implying that the two were once friends (or more) but had that friendship end poorly. However, in this series, the two do not meet in the mundane universe until episode 6, where they almost immediately hit it off and begin to develop feelings for each other. [[spoiler: Given that they're supposed to be the same characters as in ''WesternAnimation/AdventureTime'', it's unclear if this is meant to mirror how their relationship began in the previous setting before things between them went sour]].

* AdaptationalJerkass: While he seemed like a decent guy in his original fanfic appearances, DJ Flame break ups with Fionna via a two-word text message in the opening sequence.
* OutOfFocus: 6 episodes into the 10 episode series, he's yet to have a speaking role.