A permanent, one-way case of ShapeShifting. As such, it's generally taken a lot more seriously by the subject, and [[StatusQuoIsGod less likely to actually happen]]. Voluntary metamorphosis is generally only agreed to after much thought; [[EmergencyTransformation involuntary metamorphosis]] provokes much angst and anger at the responsible party.

Malicious examples can be inflicted as a form of CoolAndUnusualPunishment. Benign examples can allow a character to AscendToAHigherPlaneOfExistence. May overlap with KarmicTransformation, PinocchioSyndrome, PowerUpgradingDeformation or BalefulPolymorph.

Compare with ShapeshifterModeLock and FirstLawOfGenderBending. Not to be confused with the usual TransformationSequence, despite both ''Manga/TokyoMewMew'' and ''Anime/YesPrettyCure5'' using "Metamorphose!" as their [[ByThePowerOfGreyskull trigger phrase]], and "morph" being a key word in ''Franchise/PowerRangers''.

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!!Examples

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[[folder: Advertising ]]

* A series of commercials for the ''Franchise/RatchetAndClank'' series showed weapons from the games being used in real life in a ''Series/{{Jackass}}'' inspired way. Many of these included involuntary one-way transformations, where one guy gets turned into a chicken despite protesting, a few friends turn one of their mum's into a sheep by accident and two guys transform one of their friend's girlfriend into a cow just to mock him. And yes, they're all as full of FridgeHorror as they sound.

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[[folder: Anime and Manga ]]

* Although the use of "Metamorphose" is unrelated, ''Anime/YesPrettyCure5'' did this with most of the QuirkyMinibossSquad in their final appearances, turning them (usually against their wills) into giant superpowered versions of themselves at the cost of apparently all their higher brain functions. The BigBad and TheDragon were similar, but dodged that last part.
* Hideshi Hino's ''The Bug Boy'' is the story of a kid who is reborn as a giant bug. He suffers pretty much the same fate as Kafka's (below) protagonist.
* ''Manga/FrankenFran'' regularly features plots like this, although the protagonist's super-surgery, the transformations usually to turn out to be reversible (and into something much worse...)
* Metamorphosis is a recurring theme in ''Anime/ThisUglyYetBeautifulWorld''. The first half of the series is all about [[{{Fanservice}} Fanservice]] and [[SliceOfLife Slice of Life]] [[XMeetsY meets]] supernatural weirdness. Then CerebusSyndrome and rampant [[ButterflyOfDeathAndRebirth butterfly]] symbolism kick in. [[spoiler: The [[MysteriousWaif mysterious]] MagicalGirlfriend is essentially the AnthropomorphicPersonification of an [[ApocalypseMaiden extinction event]], although there's [[MindScrew more to it than that]].]]
* ''Anime/EurekaSeven'': [[spoiler:Eureka]] manifests [[SicklyGreenGlow glowing green]] [[AddedAlliterativeAppeal growths]] on her arm after [[spoiler:arriving on Earth.]] These eventually spread and become a [[spoiler:set of butterfly's wings on her back and cover her left arm, and she becomes fully covered in it just before becoming the new control cluster.]]

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[[folder: Comic Books ]]

* Comet the Super-Horse, from pre-Crisis DC, was originally a centaur called Biron who wanted to be fully human. Unfortunately Circe made a mistake and made him fully horse instead. Because the spell couldn't be reversed, Circe gave him superpowers to try and make up for it.
* The Franchise/TeenageMutantNinjaTurtles are all up in this trope. Aside from the turtles and Splinter themselves, there's Leatherhead, Bebop and Rocksteady, Baxter Stockman (in the first cartoon), the Mighty Mutanimals in the Archie comics, etc.
* In ''ComicBook/{{Megalex}}'', Zerain's hump bursts and a pair of wings sprout from his back when he and Ram win the battle of the twelve chiefs. This is a sign that he's TheChosenOne.

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[[folder: Fan Fiction]]
* John is permanently changed into a WingedHumanoid (with [[BlessedWithSuck various attendant perks and problems]]) in ''Fanfic/WithStringsAttached''. It's done to save his life by the Fans.
* Fan stories for ''Literature/TheLordOfTheRings'' have [[TrappedInAnotherWorld girls falling into Middle-earth]]. In some stories, the girl suddenly becomes an Elf or a Hobbit. This usually sets up a FantasticRomance with another character of the same race, and is a frequent plot in SelfInsertFic.
** ''FanFic/AmongTheEorlingas'' transforms Veronica into a horse. She is an especially strong and fast mare, but dislikes being stuck in horse form, and would like to undo this transformation. The people of Rohan think that Veronica is one of the Mearas. Théodred gives her the name Lyfgast.
** In ''FanFic/TheAwkwardAdventuresOfMeghanWhimblesby'', as Meghan enters Middle-earth, she becomes an elf. In a sequence of surprises, Meghan discovers her new RapunzelHair, her gown, her knee-high boots (a "miraculous and somewhat thrilling discovery"), and finally, her PointyEars.
** In ''FanFic/TheGamesOfTheGods'', Rachel and Kari become elves. Rachel also becomes taller, and her black hair becomes blonde. Rachel later identifies herself as a MarySue.
** ''FanFic/TroubledWaters'' is in a different category. The immortal spirit of Henneth Annûn sacrifices herself to save another life, and in result, Henneth becomes a mortal woman.
* ''Fanfic/{{Pokeumans}}'': The transformation into a Pokeuman is permanent, but don't worry because a ReplacementGoldfish clone will take care of your old life while you're away. Hope you got a species of Pokemon you like.
* In FanFic/JusticeSocietyOfJapan after gaining superpowers, [[spoiler: Kallen]]'s eyes permanently turn bright red. [[spoiler: Milly also seems to be changing in some way. But while everyone can see what's happening to Kallen, only Kallen and Milly herself can see what's happening to her.]]
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[[folder: Film ]]

* The entire premise of Film/TheFly.
* In Disney's version of ''Disney/{{Aladdin}}'', Jafar is transformed into a genie. On the other hand, ''being'' an all-powerful genie, in the sequel he gets to appear as human as he ever was whenever he feels like it.
* The movie ''Film/{{Wolf}}'' combines this with OurWerewolvesAreDifferent.
* [[OurWerewolvesAreDifferent The transformation into a werewolf]] in ''Film/GingerSnaps'' is pretty much this.
* ''Film/{{District 9}}''. [[spoiler:Wikus gets exposed to some ImportedAlienPhlebotinum, and the rest of the film details his KarmicTransformation into one of the "prawns".]]

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[[folder: Literature ]]

* ''Literature/TheAdventuresOfPinocchio'': The eponymous protagonist is a wooden puppet [[PinocchioSyndrome who wants to be a real boy]]. Eventually he gets his wish.
* In Creator/RoaldDahl's ''TheWitches'', the witches plan to dispose of all children by turning them into mice.
* In Creator/FranzKafka's appropriately named story ''Literature/TheMetamorphosis'', the protagonist Gregor Samsa finds himself turned into a giant [[strike:cockroach]] insect at the very beginning.
* Evil Magician Trent from ''Literature/{{Xanth}}'' has the power to turn any living creature into any other. He sometimes uses it on people who annoy him, like Cynthia Centaur who was formerly Cynthia Human.
* In the little-known 1980's SF/Horror novel ''Transformation'' by Edmund Plante the pregnant heroine is horrified to discover that an alien virus is [[BodyHorror transforming her]] into a psychic slug-and-lizard hybrid... at least until she she decides that [[FetishFuel a pregnant psychic alien slug/lizard is actually a pretty cool thing to be.]]
* In JackChalker's better-known 1970's novel ''The Web of The Chozen'' a human hero is transformed by an alien virus into an alien creature. One attempt at getting help from his superiors is [[HumansAreTheRealMonsters enough to convince him to abandon humanity in favor of his new species]].
* The twist behind ''The Soddit'' is that the Gandalf {{Expy}} is transforming into a dragon - as part of his natural life cycle: dragons begin life as dwarfs, grow into wizards, and finally become dragons.
* ''Some Children Wander By Mistake'' by JohnConnolly features a child being permanently transformed into a [[MonsterClown monstrous clown]], having been chosen as a fresh recruit by the other clowns several months before he was born.
* The Creator/RayBradbury short story "Chrysalis" details the metamorphosis of a man [[ILoveNuclearPower exposed to radiation]]. Other characters include a co-worker of his and a couple scientists studying him as he transforms. The entire story takes place while he is in the cocoon (or chrysalis), and everyone wonders what to do with him, if he's dead, etc. Things are further complicated when it's revealed his co-worker is showing similar symptoms and likely the same will happen to him. In the end, the man emerges from his chrysalis... and is perfectly normal. [[spoiler:Except not. The last paragraph has him fly off into outer space. It's implied his body and mind have very much transformed, but never said exactly how.]]
* The premise for Creator/EdgarRiceBurroughs' ''Literature/TheLandThatTimeForgot'' is that all the creatures on the island are evolving from one species to another as they move inland and northward.

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[[folder: Live Action TV ]]

* In ''Series/BuffyTheVampireSlayer'', a witch's rat-transformation spell turns out to be permanent when she uses it on herself - or at least, she can't undo it while transformed.
* In ''Series/BabylonFive'' Delenn enters a cocoon in order to turn herself into a [[HalfHumanHybrid human/Minbari hybrid]]. Sinclair goes through the same process in reverse to become Valen.
* In ''Series/StarTrekDeepSpaceNine'', Odo was turned into a solid (i.e. a non-shapeshifter) as a punishment for opposing his species' plan to take over the galaxy.

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[[folder: Mythology ]]

* Numerous Greek myths involved permanent transformations. Creator/{{Ovid}}'s ''Literature/{{Metamorphoses}}'' (the TropeNamer) featured a number of such stories.
** The nymph Scylla was desired by the merman Glaucus (although she brushed off his advances). The sorceress Circe also loved Glaucus, and in jealousy poisoned Scylla, transforming her into a [[EldritchAbomination twelve-footed, six-headed monstrosity]]. Scylla adjusted well to the change: she moved to a rock on the strait opposite Charybdis (also a transformed nymph) and took to devouring sailors from every ship that passed beneath her.
** Arachne and the goddess Athena had a [[CookingDuel weaving duel]]. There are many versions of this myth, and the only detail they can agree on is that the duel ends with Athena turning Arachne into a spider.
** Actaeon, prince of Thebes and renowned hunter, was transformed into a stag by Artemis and killed by his own hounds. Depending on the version, this was either punishment for spying on Artemis bathing, or for boasting that he was a better hunter than Artemis.
*** Similarly, when Siprotes saw the goddess bathing, he got changed into a [[GenderBender woman]] instead. The difference, though, was that Actaeon had ''gazed'' at Artemis, while Siprotes tried to avoid eye contact as soon as he saw her.

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[[folder: Tabletop Games ]]

* [[TabletopGame/NewHorizon Medeans]] voluntarily undergo a transformation to become Medeans.
* The Elans of ''TabletopGame/DungeonsAndDragons'' are humans who have undergone a secret, voluntary transformation that leaves them looking exactly the same, but they are effectively immortal, being able to live purely on psychic energy. There is just something off-putting about them that makes the normals uncomfortable, though: by game rules, they have become Aberrations like a rust monster or a mind flayer.
* [[http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Delver%20of%20Secrets Delver of Secrets and Insectile Aberration]] in ''TabletopGame/MagicTheGathering'', which was directly inspired by ''Film/TheFly''.

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[[folder: Toys ]]

* In ''Franchise/{{Bionicle}}'', [[spoiler: some Av-Matoran undergo metamorphasis into [[BeePeople Bohrok]] as a natural part of their life cycle.]]

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[[folder: Video Games ]]

* In the modern usages of both words, "metamorphosis" would be a much more accurate term than "[[EvolutionaryLevels evolution]]" for when this happens in ''Franchise/{{Pokemon}}''.
* The latter character from platforming series ''Franchise/JakAndDaxter'' after coming into contact with dark eco.
* Happens to [[MeaningfulName Morph]] [[MacabreMothMotif Moth]] in ''VideoGame/{{Mega Man X}}2''. He starts out as a small chrysalis, but once his health gets to half, it retreats, splits open, and then you fight the actual moth reploid. His Japanese name is even "Metamor Mothmeanos".
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[[folder: Webcomics ]]

* In ''Webcomic/GunnerkriggCourt'', metamorphosis accompanies immigration and emigration to and from Gillitie Wood. Regional Fairies and other forest-folk become humans in order to leave Gillitie and enroll at the Court, and a family of humans transform into birds before moving into the Wood.
* In ''Webcomic/{{Exiern}}'' dragons are born looking human and don't metamorphose into their true form until they reach adulthood. Adult dragons destroy human settlements and plant their young amongst the suvivors to be raised by humans like cuckoos. The heroine's pretty sure her romantic interest is a dragon (she barely survived an encounter with his half-transformed sister) but hasn't figured out how to tell him.
* [[http://skindeep.wikia.com/wiki/Anthony_Gillis Tony]] of ''Webcomic/SkinDeep'' turns into some kind of bird creature after a spell keeping him human breaks (we think)

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[[folder: Western Animation]]
* In the fourth season of ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', we have a non-living example with the Keys of Harmony; they're inanimate objects that transform into {{Cool Key}}s upon making contact with the box they're supposed to open. They do not appear to be able to change back, although we may never know, seeing as [[spoiler:they along with the box are now embedded into the Earth and have sprouted a new home for Twilight after her old one was destroyed]].
** Downplayed at the end of the third season, in which [[spoiler:the protagonist, Twilight Sparkle is transformed into an alicorn princess. Evidently, the transformation can't be reversed, but all that's really changed about her is that she has wings, a longer horn, got a little taller and is a bit more powerful]].
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[[folder: Truth In Television ]]

* Metamorphosis is a natural process for various species of animals, where their juvenile forms look little (or nothing) like the adult. The transformation of tadpoles into frogs and caterpillars into butterflies are two of the best-known examples, with butterfly metamorphosis transcending to the point of metaphor.

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