History Main / OlderAlterEgo

* Creator/OrsonScottCard's novel ''Literature/TreasureBox'' plays this for horror. Mild-mannered dot-com millionaire Quentin Fears meets - and marries, and has sex with - the girl of his dreams, but some things about her are a little odd. About halfway through the book she admits that she's been lying about her identity and is actually a witch who used magic to turn herself into his dream girl. It's not until much later in the story that Quentin and the reader find out her other secret and the real reason for her unusual behavior - that she's [[Squick twelve years old]] and has been bluffing her way through an adult romantic and sexual relationship.

* ''Anime/MagicalAngelCreamyMami'' in which a young girl became an idol singer.

* The manga ''Manga/InstantTeenJustAddNuts'' is centered around this trope. In a terrifyingly creepy manner.

* This seems to be Evangeline's power in ''Manga/MahouSenseiNegima''; however it's revealed that her "adult form" is just an illusion. Of course, it's [[PlayingWithATrope played around with]]... due to the fact that she's ReallySevenHundredYearsOld and stuck in her current form because [[OurVampiresAreDifferent she's a vampire]], Evangeline's illusion actually makes her appear ''younger'' than she really is... it's just her true form looks even younger than ''that''.

* Hono and Yuki from the ''MasterOfMosquiton'' OVA both have an adult form, which seems to be the form in which they can most effectively use their elemental powers. It's used as an excuse for blatant fanservice in the case of [[GagBoobs Yuki.]]

* In the ''VideoGame/DevilMayCry 3'' manga, Alice (who resembles the protagonist from ''Literature/AliceInWonderland'') actually goes so far as to trade her innocence to demons for the sake of becoming older and more attractive.

* In ''Anime/{{Pokemon 3}}: Spell of the Unown'', Molly decides she'd like to be older, and they make it so.

* This is how Digivolving works in ''Anime/DigimonXrosWars'', as opposed to the usual EvolutionaryLevels.

* ComicBook/UltimateSpiderMan does this... sort of. He's actually 16, but usually tells people he's in his twenties when he's in costume. No-one really buys it. Except Comicbook/BlackCat, who had once kissed him. She threw up later when she found out he was really a kid.

* The Comicbook/{{New 52}} version of Magog is a child who can turn into a superpowered adult, almost making him Captain Marvel's EvilCounterpart.

* In ''Comicbook/BigBangComics'', the Mary Marvel expy Thunder Girl is an inversion. Like the original Mary Marvel, Thunder Girl was the same age as Molly Wilson ... originally. But Molly aged in real time (except for a timeskip when she travelled from Earth-B's Golden Age to Earth-A's Silver Age), and Thunder Girl, who only exists when she's summoned, didn't. The result is that Molly is now a middle-aged woman who finds transforming into a fourteen-year-old superheroine disconcerting.
* ''{{Thunderbunny}}''. (Lesser-known 80s comic in which a boy transforms into a grownup anthro rabbit superhero).

** The ''TabletopGame/HaltevilDoer'' setting has brother and sister counterparts to Billy and Mary: Ken and Jun Masterson are twins born to Otherworld royalty, spirited out of Otherworld for their own protection as babies, and who unexpectedly awoke their true power at the age of eight, becoming the adult heroes Ultimatum and Valkyrie. As of the published setting, they're sixteen, but their heroic forms are still noticably older.

* The last episode of ''Anime/DaiMahouTouge'' uses this as part of a power upgrade. In it, the sisters of the main character, Punie, become older in an attempt to beat her and take the throne from her. Unfortunatly, they fail miserably.

* ''Anime/HimeChenOtogiChikkuIdolLilpri'' Being [[MagicIdolSinger magical idol singers]], this isn't surprising.

* In ''Manga/YuYuHakusho'', Koenma normally looks like a baby despite being ReallySevenHundredYearsOld. When in the human world, in order to be taken seriously, he appears in the form of a handsome young man... with a pacifier in his mouth. [[spoiler: He actually has a good reason to always carry the [[ArtifactOfDoom pacifier]].]]

* Subverted cleverly in ''Manga/MagicKnightRayearth.'' [[spoiler: Princess Emeraude is always seen in the form of a pre-teen/young teenager... but that's because her growth was stunted when she became the Pillar of Cephiro. Once Zagato is killed, [[BreakTheCutie Emeraude completely breaks]] and reverts to her ''actual'' age and form - that of a beautiful LadyOfWar who is [[LoveMakesyouEvil completely]] [[BrokenBird broken]] and a borderline OneWingedAngel.]]

* In ''WesternAnimation/TheTransformersTheMovie'', this happens when [[spoiler:Hot Rod opens the Autobot Matrix of Leadership, which has him grow about a foot and half, sounds much older and he becomes a RV truck in his alternate mode]]. Though this ends when [[spoiler:Rodimus Prime gives the Matrix back to a fully restored Optimus Prime and becomes Hot Rod again.]] Of course, in the Japanese continuation [[spoiler:Rodimus Prime gets the Matrix back and regains the larger form when Optimus sacrifices himself ''again'']]

* In ''Series/{{Smallville}},'' an enchanted comic book turned a boy into an adult superhero. Chloe seemed semi-interested in him (with a FlightOfRomance, no less) until she found out he was really about ten years old. [[spoiler: Turns out, though, that the comic wasn't about a hero, but a villain's StartOfDarkness, and the kid was cursed to go AxCrazy the moment he felt betrayal.]]

* Franchise/ArchieComics Superhero ''[[http://en.wikipedia.org/wiki/The_Fly_(Archie_Comics) The Fly]]'' (also known as Fly Man) was originally one of these. Young orphan Tommy Troy was given a magic ring that allowed him to transform into an adult with insect-based powers. Unusually for this trope, the age differential didn't last. By the fifth issue Thomas Troy had aged a good ten years, gaining a law degree along the way, and was drained of any lingering trace of originality. (This was concurrent with the departure of the original Joe Simon/Jack Kirby creative team.) When The Fly and other Archie Comics heroes were revived under DC Comics' Impact imprint, this trope was re-established for the character.

* As created by Mick Angelo, [[ComicBook/{{Miracleman}} Marvelman]] originally had this, being a CaptainErsatz of Captain Marvel. When Creator/AlanMoore wrote the character, he had Micky Moran grown up.

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* ComicBook/UltimateSpiderMan does this... sort of. He's actually 16, but usually tells people he's in his twenties when he's in costume. No-one really buys it. Except [[DatingCatwoman Black Cat]], who had once kissed him. She threw up later when she found out he was really a kid.

* In the 2019 series ''DialHForHero'', Miguel's "inner hero" alter ego [=SuperMiguel=] appears about the same age as Miguel's idol Superman.

** Yellow heart is actually a forceably age-adjusted [[spoiler:Peashy; her CPU form was artificially made an adult to best capitalize on her strength. She later gets her child body back, but still becomes "the big me" when she transforms.]]

* In ''Comicbook/BigBangComics'', the Mary Marvel expy Thunder Girl is an inversion. Like the original Mary Marvel, Thunder Girl was the same age as Molly Wilson ... originally. But Molly aged in real time (except for a timeskip when she travlled from Earth-B's Golden Age to Earth-A's Silver Age), and Thunder Girl, who only exists when she's summoned, didn't. The result is that Molly is now a middle-aged woman who finds transforming into a fourteen-year-old superheroine disconcerting.

* ''Manga/AyashiNoCeres'' has an odd partial example--Aya's friend and fellow ten'nyo Chidori is in her late teens, but physically looks about ten. When she transforms into her ten'nyo form, however, she looks her actual age.

* This was the premise of ''Manga/FullMoonOSagashite.'' In addition to Mitsuki going from 12 to 16, she also temporarily loses the throat cancer she has as a 12 year old which prevents her from singing loudly. And in order to properly disguise herself during her first transformation she dyes her hair blonde. After that it's just assumed that Takuto and Meroko include the dye when they transform her each time.

** This is PlayedForDrama in WesternAnimation/StevenUniverseFuture. Jasper's training plus Steven's poor mental health causes him to become DrunkWithPower, drastically changing his appearance and physique so he looks like a JerkJock. After [[spoiler:he accidentally shatters Jasper]], he's back to his usual self, implying that this was an example of age-related shapeshifting.

** This is PlayedForDrama in [[WesternAnimation/StevenUniverseFuture]]. Jasper's training plus Steven's poor mental health causes him to become DrunkWithPower, drastically changing his appearance and physique so he looks like a JerkJock. After [[spoiler:he accidentally shatters Jasper]], he's back to his usual self, implying that this was an example of age-related shapeshifting.

** This is PlayedForDrama in ''[[WesternAnimation/StevenUniverseFuture]]'' Jasper's training plus Steven's poor mental health causes him to become DrunkWithPower, drastically changing his appearance and physique so he looks like a JerkJock. After [[spoiler:he accidentally shatters Jasper]], he's back to his usual self, implying that this was an example of age-related shapeshifting.

* In ''Series/OutOfThisWorld,'' Evie once turned herself into an adult, becoming "Evie's older cousin Yvette," to attract a boy. Attempts to reverse it rendered her seven years old.
* In ''Series/{{Smallville}},'' an enchanted comic book turned a boy into an adult superhero. Chloe seemed semi-interested in him (with a FlightOfRomance, no less) until she found out he was really about ten years old. [[spoiler: Turns out, though, that the comic wasn't about a hero, but a villain's StartOfDarkness, and the kid was cursed to go AxCrazy the moment he felt betrayal.]]
* Justin in ''Series/PowerRangersTurbo'', mostly as a result of the suit-actor being the same age as the rest of the suit-actors, while the character actor was about [[DawsonCasting half the age of the other character actors]], with no actual in-story handwave. He even shifted back to twelve-year-old size when he removed his helmet. (We never saw that happen directly, sadly. When the Rangers would be suited but unhelmeted around the base, Justin would be wearing a kid-sized suit, all size-shifting happening offscreen.)
* This pertained not only to ''Power Rangers'', but in ''Franchise/SuperSentai''. ''Series/GoseiSentaiDairanger'' features a 9-year-old that became the Kiba Ranger with the same circumstances. His living sword speaks for him while he is hiding his identity from the other Dairangers.

* Thunderbolt Jaxon was another homegrown British {{Exoy}} of Captain Marvel, a boy who, using a magic belt, could transform into Thor.

* The main characters of ''Series/BigBadBeetleborgs'' are all kids who thanks to a Phantasm called Flabber [[AscendedFanboy become their favorite heroes]]. (Note the only the ''Dairanger'' example has to get around adult-sized heroes sounding like kids. Even people who know the kids and meet the heroes don't ever say a word about the voice thing.