Okay, named in honor of his theme music, as he has in fact sevenwings, but just one in place of an arm.
Video games in general absolutely adore having their final boss do this, even when their original form is scary enough anyway. In fact, it's gotten to be somewhat of an arms race: thanks to the popularity of Frieza in 1991, three-form bosses are now somewhat common, and those games going for "epic" will sometimes go for even more. In JRPGs, particularly, it is rather common to see two stages of One-Winged Angel: the "bizarro" form, that is huge and scary, and the "angel" form, that is winged, eeriely beautiful and accompanied by Ominous Latin Chanting (the original One Winged Angel, Sephiroth, is the codifier of this subtrope). Once beaten, or on becoming even more powerful, the villain may cross the Bishonen Line and into safer territory for an Evil Makeover to work its magic (though it's a huge case of Tropes Are Not Bad; as much as it's used, you'd be hard pressed to complain when they turn into something fucking awesome).
Sometimes you never even fight their human form at all and they immediately turn into a monster. Can count as The Unfought if they showed fighting ability in their human form. This is more popular among minor video game villains who will often transform into tougherversions of earlier monsters like in the Breath of Fire and Final Fantasy games, as it takes time to create a unique battle sprite for them.
Interestingly, heroes, particularly transforming characters, have been known to use this "turn into a big scary monster" tactic as well. It's extremely rare for it not to cross into Superpowered Evil Side territory.
Sadly, this transformation can often be anti-climactic, as it telegraphs to the audience that the villain will most likely face his final defeat soon. Outside of video games, it is quite rare for a bad guy to invoke this trope and actually WIN. This might be because the less human a character looks, the more "acceptable" it is to kill them.
Scaled Up and Make My Monster Grow are major subtropes. See also I Am Not Left-Handed, Evil Makes You Monstrous and Shapeshifter Showdown. Compare Emergency Transformation, Came Back Wrong, and Not Even Human. One subversion is to make it a Clipped Wing Angel.
For those looking for actual winged people, see Winged Humanoid and Our Angels Are Different.
Examples
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Anime and Manga
Heroic example in Howl's Moving Castle. Near the end, Howl transforms himself into a giant flying bear/wolverine-eagle thing to fight off bombers.
When Sebastian reveals his true form, we don't get to see it, but it apparently includes black feathers and stripper boots, and is so horrible that Ciel is not allowed to watch. Ciel's seen some pretty messed up things.
Digimon Frontier has a Big Bad named Lucemon who starts in the form of a child-like angel with wings and blonde hair and shiny light powers. He then turns out to be a fascist dictator and gets steadily deeper into One-Winged Angel territory over three new evolutions.
Between the various forms of the villains in other series and the increasingly (sometimes ludicrously) powerful Digivolutions on the heroic side in all series, Digimon loves this trope. The next best example is Myotismon becoming VenomMyotismon, a humongous and less intelligent form of Myotismon. In Season 2 he returns as an even stronger and more sadistic MaloMyotismon before he is finally destroyed for real.
Even a human has gotten in on it. Kurata, the Big Bad of Digimon Savers ultimately fuses with the Demon Lord Digimon Belphemon, taking direct control of it, his face appearing on its chest. Belphemon itself also counts, as this triggers its mode change from its cute Sleep Mode to its Kaiju-like Rage Mode.
AKIRA is famous for this, thanks to the infamous giant fetus... thingy. It includes a final villain ultima-monster transformation, using it to introduce some fairly complex questions about humanity and monstrosity.
Also, the Abyssal Ones (Or any other Awakened Beings that we see more than once) tend to run around in their human forms until they get into a serious battle.
And then there's Dragon Ball, though it typically happened on less grand a scale — the villain announces that he's changing to his "true form", then becomes larger and more muscular. (Some do this more than once!) And of course the Saiyans have their Super-Saiyan forms.
Freeza's initial form is small and rather weedy looking, but has proved to be extremely powerful in previous confrontations. He transforms into a much taller version of himself, then an even larger, monstrous beast with an elongated head and spikes on its back. However his much-hyped final form turns out to be just as small as his original, but more sleek and aerodynamic, effectively crossing the Bishonen Line. At first he is mocked for this, but soon proves that the extra speed and strength far outweighs what he lacks in height. And then these are followed by a more muscular form of the same, and after losing much of his body after his defeat on Namek and coming to Earth for revenge, a cyborg form.
Likewise, as Cell steps closer to his 'Perfect' form, he becomes steadily more humanoid.
Zarbon's case is an interesting one - obsessed with his own beauty, he is incredibly reluctant to transform even temporarily into his ugly-but-powerful hulking monster form, and consequently determined to beat the shit out of the protagonist whose power forces him to do so or lose.
Majin Buu has the most transformations of any character in the entirety of Dragon Ball, as he assumes a new form and undergoes some personality changes every time he absorbs a person. He was created as a shrimpy little guy who has no vocabulary whatsoever and blows up planets for giggles; becomes very buff after absorbing the Southern Supreme Kai; turns fat and goofy after absorbing the Grand Supreme Kai (the form the heroes first encounter him in); expels the embodiment of its evil side as a pale, wiry thing; becomes muscular and savage when the evil side reabsorbs the good side; absorbs Piccolo and Gotenks to become smarter and more powerful with a more human face and longer antennae; reverts to a Piccolo-based form when Gotenks' fusion runs out; absorbs Gohan to take on his most human form yet; and then when Goku and Vegeta free all the fighters he absorbed he finally reverts back into his original form before all the transformations began. Counting Majuub, that's nine in total.
Then there's the whole Oozaru thing. In an episode of the Saiyan saga Vegeta has a move that allows him to go Oozaru by creating a ball of energy that looks like the full moon — he uses this move and turns Oozaru. Amazingly he's still able to speak while being in this form, which was explained as him being trained to have some control over the form (as opposed to the only other Oozaru appearing being entirely untrained kids - Goku and Gohan).
And pre-redemption Piccolo grew building-sized at one point; same for Lord Slug.
Garlic Jr goes from looking like a paler midget version of Piccolo without the antennai (or like Emperor Pilaf) to looking like a bulkier, more adult-height version of the same.
Sometimes happens to individual Duel Monsters in Yu-Gi-Oh!, particularly the Winged Dragon of Ra.
Although in one episode Kaiba actually transformed into a Blue Eyes White Dragon.
In the manga, near the end of the tabletop RPG against Yami Bakura, Zorc transforms into a super-form after his regular form is defeated. Yami Yugi even lampshades this by stating that, while horrifying, this is probably Zorc's last form.
In the anime, there is an arc where the main characters are trapped in a virtual world and fight the evil Noah, whose father is Gozaburo, Kaiba's evil stepfather whom he battles in the end. After Kaiba wins, Gozaburo transforms into a beast of fire, but Noah holds him back and both remain as the virtual world is destroyed. Somehow, Gozaburo survives just long enough to appear for a few moments in the real world as a beast of fire and part of the explosion, but they escape him before he can eat them.
Considering that the real-world island is exploding as Gozaburo activated it's self-destruct as a last-ditch effort to kill the heroes, and that Gozaburo became a beast of fire in the virtual world, the explosion taking on his beastly characteristics was likely meant symbolically than Gozaburo literally manifesting in the real world.
Pokémon may seem too casual an example to list here as Pokémon evolve all the time, but when an important character's Pokémon evolves to their final form right before (or even sometimes in the middle of) a huge battle in the anime, this Trope is definitely played straight.
Played even straight in Pokémon 4Ever where just right after Celebi is corrupted by the Iron-Masked Maurauder, it actually transforms into a giant monster made from twigs and leaves which for some reason resembled a Darkrai.
Naruto has this a fair bit. A couple of the purer "villain" forms of the transformation involved Gaara's grotesque mutation into his demonic Shukaku form, and Orochimaru's curse seal's second stage, which turns the bearer into a monstrous version of their former selves: various members of the Sound Five grow horns, spikes, deformed facial features, an extra eye, and a tail from using it, and Face Heel Turn Sasuke actually grows hand-like wings.
Orochimaru himself has a grotesque "true form" that he transforms into whenever he performs his body-switch technique. He takes the shape of a giant white snake made up of a multitude of smaller snakes, with a monstrous, dragon-like face and shaggy black hair. He also has a jutsu that allows him to transform into a giant "hydra", one of the mouths of which holds his normal body.
All the Akatsuki have a One-Winged Angel form in one way or another. Kakuzu's tentacle mass thing, Hidan's Grim Reaper form, Kisame's Samehada-Fusion form, Itachi and Sasuke's Susano'o, Madara's Intangibility form, Sasori's real body... Pain and Deidara are the only who lack it.
And Pain already consists of six remotely controlled zombies; his final revealed form was a creepy wasted body impaled by many chakra antennae. Deidara did the thing mentioned in the trope description of becoming a living bomb.
Spoofed on Bobobo-bo Bo-bobo. The villain Over has six lights on his chest that light up when he gets mad. When all six are lit up, he transforms into his true self... Torpedo Girl. Yes, it's exactly what it sounds like.
Another example is an enemy's true form being "Sambaman", an enemy whose method of attacking is... dancing the Samba. No, really.
Yet another example is Bald the III after absorbing both Bobobo and Don Patch. This is the guy◊ and this is what he becomes.◊. When a villain invokes this trope, expect something very silly to happen.
Another spoof would be Neko Majin Z, in which Neko Majin transforms in a way so subtle he is forced to point it out ("Look closer... I have double eyelids").
The Arrancar in Bleach transform (or revert back) into massive hulking demons when they release their zanpakutou. One of them even utters one of the page quotes above just before doing this.
Chad, a protagonist, had a similar line, "This is my right arm's true form," when he used his new ultimate technique, "Right Arm of the Giant", against the Arrancar Gantenbainne Mosqueda. Also, during Ishida's climactic, personal fight in which he gained a momentous amount of power temporarily at a permanent cost, he took on a literal manifestation of the trope, complete with a spirit-particle-absorbing wing.
Ulquiorra Cifer actually grows gigantic wings during his two releases. In fact, his final fight with Ichigo even ends with one of his wings missing, although he's really more of a devil than an angel.
Yammy Llargo, who grows gigantic, and reveals that his number is not 10, but 0.
Kaname Tousen, who becomes a huge bug creature, giving him sight(never had sight mind you), then proceeds to get owned then appears to die in the span of 5 chapters.
"You never would have let me get an opening like that, when you were blind."
The Big Bad has spent 20 chapters or so gaining new "evolved" forms.
Happens nearly every week in Vampire Princess Miyu. The exception is the last episode, where the final monster looks almost entirely human, making it somewhat less fine to kill her. The fact that the monster was Miyu's best friend all along does not really help either.
In Yaiba, Kaguya transforms back to her true, gigantic form after she drains the essence of youth out of Sayaka.
A very, very nasty subversion takes place in the final episodes of the Fullmetal Alchemist anime. In the middle of his battle with Edward, Envy finally reveals what he really looks like. He actually looks a great deal like Alphonse... his younger brother...
A few minutes later, of course, Envy plays the trope straight and turns into a giant snake (well, a serpentine dragon-thing at least). It doesn't help.
Note that all of this is very different from the Manga, which uses a more typical version of this trope at first. Envy's true form is... well, you'd hate to meet him in a dark alley. Or a light alley for that matter. However, this is also subverted. Envy's true true form, devoid of all the souls that compose his body, is that of a physically harmless embryo-like lump of flesh. It can still talk, and it convinces Mei Chan to return to Central where it can get "healed".
Downranked into a Clipped Wing Angel later when Mustang points out that the huge size makes it that much easier to aim.
Some of the other Homunculi have monstrous true forms as well. Manga Gluttony opens up his torso to reveal a false Gate of Truth, Greed grows a black diamond skin over his body, which also sets off his sharp teeth to fangy advantage, manga Pride becomes a replica of the shadows behind the gate, a swirling mass of darkness, eyes and hungry mouths. Manga Wrath and Anime Pride, Lust, Wrath, and the Sloths haven't or didn't show any alternate form other than small transformations (Lust's nails or anime Sloth's water body), though manga Sloth is pretty monstrous to start with. In the movie "Conqueror of Shamballa", Gluttony is seen roving about the sewers as a giant, monstrous version of his typically oafish body.
In the new Brotherhood anime, Father Cornello transformed as well.
After becoming a great black mass (and consuming his body and his 'father') he crossed the Bishounen line and turned into a teenage Hohenheim, also known as "the one that looks like Fullmetal without the automail!" Only slightly prettier and shirtless.
And then he turned into a black giant, and then he was swallowed by the Gate, because the Sin of Hubris was by no means contained in his eldest son, no matter what he thought.
Subverted later on; after Negi single-handedly wipes out a gang of bounty hunters, the leader starts muttering about revealing his true form. Negi gives him a mean look, and he goes back to cowering on the ground.
Used again when four of Fate's minions all revealed more powerful forms to fight Jack Rakan. Not that it helped any.
This also happens to Negi when Kurt Godel revealed who was responsible for the attack on his village, and Negi's ensuing uncontrollable rage caused his Magia Erebea to run rampant and transform him into a monstrous black daemon whose only thought patterns are "KILL". He's currently undergoing Training from Hell so that he can actually control the power, rather than going into a blind rage. Its implied that "control" here means "it's turned on all the time" as a downside.
In Ranma ˝, Pantyhose Taro is cursed to become a winged minotaur-like creature with an eel's tail (Spring of Yeti Holding an Eel and a Crane While Riding an Ox). Before, that is, he added octopus tentacles. Whereas most characters loathe or at least dislike being cursed, Taro loves the added power and takes advantage of it at every opportunity. (It probably helps that he was cursed as a baby.)
The final arc of the manga pitted the Nerima crew against an entire race of people who could turn into angel-like creatures (to be fair, they were genetic mutations from having drunk Jusenkyo water for generations.) But the Biggest Bad of them all, the one enemy that puts all of Ranma's prior foes to shame, started out as an obnoxious little kid who transformed into a living, breathing nuclear power plant with great golden wings and the regenerative powers of a Phoenix.
At least one fighting game used Pantyhose Taro's forms to its advantage by making him the final boss - Round One is against the human, and then he splashes himself with cold water before Round Two.
Hokuto does this near the end of the first season of Rosario+Vampire (manga version), after he tears off his holy lock that keeps him from losing his humanity.
Earlier in the series, Kuyo eventually shifts into what he considers to be his "ultimate battle form", which combines the strengths of both his "human" form and his monster form.
Happens in every Sailor Moon movie and the season finales.
Or at least the first and last season finale, in which Queen Beryl's dying body is possessed by Queen Metaria and becomes a... giant Queen Beryl, and Queen Nehelenia turns old and ugly (though this was a result of her leaving the mirror that kept her young, and this seems to weaken her, though she can still fight well). Though Germatoid should count, as he was the Daimon who was Possessing Doctor Tomoe, and is revealed to be a gigantic monster. Though not a season finale, Esmeraude is transformed into a dragon by Wiseman before Sailor Moon destroys her.
In Sailor Stars, Chaos first possessing Sailor Galaxia and then taking on his own form in the manga fits right in. As a less extreme version, the anime-version of Galaxia becoming very much like an undead beast midfight with Sailor Moon should also count.
An ongoing theme in Soul Eater, where there are living beings that can transform into weapons, retaining human form to interact with others and maneuver of their own will. They can also temporarily transform into an amplified weapon form by merging their souls with their Technician. Moreover, one of the major villains of the series (The Demon God himself) assumes a large, grotesque form during the last battle of the anime.
Practically a recurring joke with Arachne's ancient second-in-command, Mosquito. Every time the techs are just about to beat him, he invariably reverts to stronger and stronger (younger) versions of himself, proclaiming each to be when he was at his "physical peak". (He pulls a Bishonen Line when he fights Kid. It's later subverted when he fights Noah. He goes into what he says is his most powerful form ever, and gets killed in about three seconds.)
In the manga version of Gantz, a couple aliens have this, but the most extreme example is the Nurarihyoon alien, who goes through quite a large number of different forms, each appearing after the previous form is seemingly killed. The forms vary wildly, from an old man, to a hulking horned beast, a demon-like creature, a floating ball, a giant naked woman made out of other naked women, and at least one more demonic form after that.
Berserk's Apostles typically have two forms. The first is their regular human form, often with some monstrous feature that serves as their "tell." The other is their full demonic form, which they typically go into when their regular form is not enough. Zodd has the form of a winged humanoid monster with a horned tiger's head and hooved feet, and later on in the manga loses one of his horns to Griffith and becomes his Dragon. Grunbeld has the form of a powerful crystalline dragon. And Rosine has a "fairy" form in addition to her true demonic form.
The entire Living ShipGrey Geshpenst from Infinite Ryvius undergoes this process during the final battle, absorbing a bunch of Space Whales into itself and transforming from a normal-looking spaceship to a massive organic... thing.
Stinger and Cohen from Getter Robo: Armageddon pull this at the end, fusing together and becoming some kind of planet sized Living Ship that can spew waves of Invaders.
A few examples in One Piece. Virtually anyone with a Zoan fruit will have this to some degree, though only Rob Lucci and Kaku try fighting without their fruit powers. More notably, Eneru and Gecko Moria both go One-Winged Angel shortly before being defeated, with the former turning into a giant thunder god and the latter absorbing a thousand shadows to become a giant four-legged shadow demon...lizard...thing.
And now there's a few more examples: Magellan when he uses Hell's Judgement to sit himself in a giant demonic skeleton of corruption that threatened to destroy the entire building he was in (this one was actually unbeatable, effectively being an Advancing Wall of Doom), and Sengoku the Buddha, who proves his moniker by becoming a giant golden Buddha statue with energy blasts from his palms.
To be fair Chopper's Monster Point ought to count. It's got huge downsides, but it certainly is a monster transformation capable of taking down most enemies.
All of the Chevaliers in Blood+, but especially James...
In Yu Yu Hakusho, Yusuke fights numerous demons, many of them start out fighting in human form, and then when they are losing they shift to demon form in order to increase their fighting power. Oddly enough, considering how violent demons are, many demons seem to prefer wandering around in human form even when there's no need to hide what they are (Hiei is a good example of this, since even when fighting the Saint Beasts in an all-demon town he says in his mostly-human form).
That is his true form. That's his body, it's what he looks like. He added the third eye through surgery. Since his behavior during his introduction was so out of line with the rest of his characterization, people have mostly concluded that stupid zombie-making sword was messing with his head, and that he normally knows better than to use the Jagan to cover himself with eyeballs, which may come with a power boost but means having weak spots absolutely everywhere. He's primarily a swordsman, after all.
In an amusing and well-deserved subversion/Clipped Wing Angel, the Complete Monster (literally, figuratively, and any other way you can think of) Dr. Ichigaki gives himself an injection, transforming into a gigantic monster with extendy-claws. A pissed-off Yusuke annihilates Ichigaki in no time flat.
Nyanko-sensei from Natsume Yuujinchou usually spends his time in the body of a Fortune Cat - except when in battle, then he turns into this.◊
Sesshomaru from InuYasha can transform into a giant dog... though he generally doesn't need to do it much, and in fact is only seen adopting that form twice throughout the series, once not in combat.
May qualify as Clipped Wing Angel, since the first time he ever turned into a giant poodle was in his introductory episodes, whereupon he promptly got a forelimb whacked off by his 'worthless' little half-brother. This renders him moderately crippled even in human form, although he's awesome enough to cover for it most of the time, but as a dog he have difficulty even walking. Probably why we don't see that again. Well, that and his value as bishounen.
Naraku also fits this trope: in the final battle in the manga he transforms into a monster-sized spider, whose body Inuyasha and gang then enter. They then encounter Naraku's human body once more, which undergoes a final form change.
Prior to that, he gets a term as a literalOne-Winged Angel, immediately after absorbing Moryomaru. And yes, just like the Trope Namer, his wing is in place of an arm.
Naraku adopts new forms and bodies like most people change clothes. More than the main cast change theirs. It's in his nature as a fusion-thing with limitless ambition.
Alucard from Hellsing uses this frequently in the form of removing his Power Limiters, to the point of not having much of a 'true' form. Paladin Anderson uses a nail from the Cross to become a thorn-monster. Also, Seras manages to pull off the One Wing (in place of an arm) look later in the series.
The mikura of Karas have this, transforming into mechanical monsters for combat.
Katekyo Hitman Reborn! has the Six Funeral Wreaths, a villain group who each have their box weapons embedded in their bodies. Their ultimate ability is to activate said weapons, which turns them into powerful half-animal beings.
And three of them end up getting tricked into activating their transformation just so their boss can absorb their power, in order to fuel HIS one-winged angel transformation.
In D. Gray-Man we get a good example of this when Tyki Mikk loses control of his Noah. He turns into an armored fiend with a good dozen tentacles coming from his back and a taste for blood. Literally.
Mazoku generals Drum and Guitar from Violinist of Hameln normally appear in relatively small and goofy-looking (although still extremely dangerous) forms, to conserve their finite amount of magical power/lifeforce. When pushed, they can transform into a city-sized, many-headed dragon and an Accidental Nightmare Fuel-inducing cerberus, respectively. Vocal, however hard this is to believe, after witnessing his Crazy Awesome acts of monstrosity is also sealed in a form that only utilizes 1/10th of his maximum power, however, in a subversion, his true form is basically a White-Haired Pretty Boy version of him and exhausts most of his remaining magic in half a minute, causing Superpower Meltdown.
The trope is so old and frequent, it has received numerous parodies for decades. Some time in the '90s, Houshin Engi even went ahead and lampshaded the common downside: "Villains who turn into a giant monsteralwaysdie."
Kind of a weird example in Madoka Magica: Charlotte has what can be best described a giant worm-clown thing as a tongue, and it only shows up after she's been beaten on for a bit. Oh, and witches are One-Winged Angel forms of Magical Girls.
In the fourth-to-last episode of Sonic X's third season, Dark Oak, Black Narcissus, and Pale Bay Leaf use a Planet Egg and all seven Chaos Emeralds to merge together with an all-water planet with a tree on top of it to transform into a massive three-headed plant dragon resembling King Ghidorah from several Godzilla Toku films.
Also, the male Seedrians were shown to be capable of turning into giant Godzilla-like monsters years before five of them survived and became the five Metarex commanders.
Done intrestingly in Bakugan. Season 4 Big Bad Mag Mel and his partner Razenoid turn out to be the One-Winged Angel incarnations of the previous seasons Big Bad Emperor Barodius and his partner Dharak after being exposed to the power of the Bakugan god Code Eve.
Meanwhile, cards that do this to CREATURES in Magic: The Gathering are too many to count. Green in particular is notable for being able to transform even the meekest creatures into game-ending monstrosities. However, on top of it all is Eldrazi Conscription, which apparently can transform any creature into an Eldritch Abomination.
In the Crisis Crossover starring Onslaught itself, he took three forms. The first was armor patterned on Magneto's with Spikes of Villainy added, completely encasing a body with the size and musculature of the Hulk. In the second form, the armor was the same, but adapted for a body that was now even larger, but more low-slung with much bigger forearms, and a bony face was visible, and balls of pure energy leaked out of his back and vents in the armor. His third form was disembodied pure energy, and he was defeated just pages after taking this form.
There was also an X-Man character whose power was transforming into whatever his opponent was afraid of (he may have even been named something like Nightmare). The twist was, he was a good guy, and actually otherwise reallynice.
That's Trauma from Avengers: The Initative who transforms into the fears of others. Nightmare is in fact his father.
There are many mutants in the Marvel Universe who can transform, some of them really transform into ugly, instead of cool or powerful ones. The morlock Scaleface for example was a normal woman who could transform into a giant lizard.
There was also Freakshow from the run of Excalibur set on Genosha. He was able to transform into various monstrous forms.
The Clown, a major enemy of Spawn, spends most of his time in the mortal realm disguised as a short, overweight circus reject. But piss him off, and he'll reveal his true form - the large, powerful demon known as the Violator - and deliver a No-Holds-Barred Beatdown upon your ass.
In Amulet, this happens to anyone who gets "devoured" by the amulets. So far we've seen Luger grow into a giant troll-like creature.
One of the EGM Hsu and Chan comics has the title duo getting roped into a wrestling match against Satan. He initially appears as a long-haired blonde in a white suit, but when the match begins, he reveals his true demonic form...a skinny, red-skinned guy with horns and pantaloons, not unlike Pitch.
The Sentry when he becomes the void, especially in Siege.
Batman villain, Scarecrow, is definitely one of these as Scarebeast.
X-Men villain Bastion has his own One Winged Angel form at the end of the recent Second Coming event. He doesn't last long once Hope Summers gets well and sufficiently pissed.
Jean Grey's Dark Phoenix may count as well. While wings are pretty standard for Phoenix nowadays, Dark Phoenix's fiery, psychic energy wings and her tendency to eat stars when she's hungry certainly qualify her for a number of things.
In Megalex, evil and beautiful Sapient Ship personality Shalise transforms into an absolutely terrifying monstrous version of herself. Her mouth fills with fangs, her ears become bat-like, she grows in size, and worst of all, her beautiful breasts become pendulous and rotten, tipped with corroded metal blades.
Films
Kadaj, in Final Fantasy VII: Advent Children, transforms into no less than the Trope Namer himself. Shortly after being super-Omnislashed, Sephiroth proceeds to show his lone black wing, before leaving Kadaj to go through the whole 'dying' process.
In Advent Children Complete the wing appears before Sephiroth is Omnislashed, and he uses it to do a number on Cloud.
Mention must also be made of the Teenage Mutant Ninja Turtles cartoon that only aired in Japan (and has gained a bit of notoriety online as many viewers assume that it must be an elaborate parody). In this series, the Turtles were granted magical crystals that allowed them to transform into superpowered forms. Sadly, Shredder, Rocksteady, and Beebop found evil versions of the same crystals and are now capable of turning into superpowered monsters. At this point, it's probably better just to direct your attention to the show's opening sequence.
Happens all the damn time in Men in Black (both the comic, movies, and AnimatedAdaptation) whenever the disguised alien villains expose themselves in front of J and/or K. One has to wonder why they don't just shoot before the transformation is complete, what with the guns usually loaded and pointed at the alien during the transformation.
However, they may be following the grand tradition of movie aliens flipping out and assuming monstrous forms to attack. The Thing does it (quite a lot really). So does Sil in Species.
For the film, it was justified since the Bug had eaten the galaxy and shooting him would probably have destroyed it.
Happens to the villains in both 2003's Hulk and 2008's The Incredible Hulk. Then again, this makes sense as The Hulk himself could qualify as the heroic version.
In one of the Alien Nation films, the Big Bad takes a massive overdose of the MacGuffin slave-drug, seemingly dying, and then...
An early idea for The Lord of the Rings grand finale was to show Aragorn battling Sauron in the last battle. Sauron (just an gigantic red eye up to this point) would first be seen as a tempting angelic bishonen◊ (Kate Winslet in cameo) who then transform into the gigantic armored fighter seen in the first movie's prologue. The filmmakers eventually decided that this was silly (and an inconsistency, since they had decided that Sauron wasn't supposed to be powerful and capable of fighting without his ring) and replaced the armored Sauron with a troll.
This is because Sauron is a Maia (angel), sort of like Gandalf. The beautiful side was his original form and he used it to corrupt Aragorn's ancestors. Eru Ilúvatar destroyed Numenor and Sauron lost his body. He got better, but could never regain his beautiful form and had come up with a badass one instead. Thus the above scenario would have violated canon, but that probably wouldn't have bothered the film makers since they had already swapped Sauron's physical book-form for a giant red eyeball.
Dracula and his brides in Van Helsing can turn into harpy-esque bat things. And in the finale, Van Helsing himself becomes a werewolf to battle Dracula, who has turned into a giant demon thing.
In the 2002 live action Scooby-Doo movie, Scrappy(!) turns into a demonic version of himself with razor sharp claws and teeth, a big muscular body, wild looking eyebrows, enhanced agility and strength- A DEEP BOOMING VOICE and a horrid case of bad breath.
According to the bonus features on the DVD of the first Blade movie, this was the original ending of the film, with villain Deacon Frost transforming into the blood god La Magra (who looked like a giant CGI red tornado). However, the filmmakers were struck with a jolt of good sense and realized that it would detract from the climax, having just spent the entire film building up Frost as the main villain. Instead, La Magra possesses Frost, granting him nigh-invincibility and fighting prowess.
The Penguin in Batman Returns is another non-fantastic example. As a derelict living in the sewers, he wears nothing but a thick robe over slime-stained long underwear. Once he decides to compete in Gotham City's mayoral race, he begins appearing in public in a tuxedo shirt, a waistcoat, striped pants, a bow tie, and a top hat. Fleeing the city in disgrace after his hypocrisy is exposed by Batman, Penguin loses his hat and retreats back into the sewers, where he begins stripping off his fancy suit. For the rest of the movie, he appears only in his robe-and-long-underwear combo - signaling that he has returned to his "normal," quasi-animalistic self.
Some of the monsters in the Godzilla series can change form. For example, in Final Wars, Monster X transforms from a skeletal dragon into the more powerful Keizer Ghidorah (Which is essentially an Expy of both King Ghidorah and Desghidorah (a quadrupedal three-headed dragon Kaiju)).
Likewise, there's Destoroyah who changes from a pretty dang big crab/scorpion-esque monster into what looks like a kaiju version of The Devil that towers over Godzilla himself.
In Lisztomania, Richard Wagner turns into a grotesque vampire at the final showdown with Franz Liszt.
In Tenacious D And The Pick Of Destiny Paul F. Tompkins changes into Satan and KG and Jables challenge him to a rock-off.
Ghostbusters has the scene at the begining where the librarian ghost turns into a hideous ghoul when the GBs are trying to get her. Interestingly enough, there was an earlier librarian ghost puppet that got rejected because it was too scary, but it was recycled and used in the 1985 vampire film Fright Night (see below).
Parodied at the end when Gozer, who initially appeared as a young woman, demands the Ghostbusters choose the form it will use to destroy them. All the GBs clear their minds except Ray - who unintentionally thinks of the Stay-Puff Marshmallow Man.
The Witches of Eastwick has the scene where Jack Nicholson's character becomes a giant and then after the girls smash the wax voodoo doll of him becomes a worm-like monster.
In the 1985 vampire film Fright Night the vampires have three phases of transformation, the first is typically like a normal human, the second is like a normal human but with fangs, and the third phase is a extremely crazy looking monstrous creature with More Teeth than the Osmond Family. At the end Jerry Dandridge (the main vampire) turns into a human/bat hybrid thing, gets hit by sunlight and bursts into flames and finally dies. Interestingly enough, the vampiric version of Amy is in fact a recycled version of the rejected librarian ghost from Ghostbusters.
Resident Evil Extinction has the big bad evil scientist injecting himself with a massive dose of secret formula and then mayhem ensues. Of course.
So does "Resident Evil: Degeneration"
Except that in Degeneration, he was more of a Well-Intentioned Extremist, who's plan was to go on a rampage, exposing the research on the G-virus that was being done.
In The Film of the Book of Coraline, after The Other Mother loses her temper with Coraline and tries to stop her from escaping, she gets less and less human-looking. At first, she simply becomes inhumanly tall and gaunt; at the climax, she turns into what is best described as a spider-woman with giant sewing needles for limbs.
The main villain in the 1980s Eddie Murphy Vehicle The Golden Child spends most of the film looking like actor Charles Dance. At the Final Battle, and with no foreshadowing anywhere in the film, he transforms into a large, bony, winged demon (stop-motion animated to boot), whereupon Murphy kills him with a special knife.
At the climax of Enchanted, Queen Narissa uses her magic to turn herself into a large dragon and plans to kill everyone.
Eddie Quist's transformation into a werewolf near the end of The Howling could be called this.
Toward the end of Conan the Barbarian (1982), the villain Thulsa Doom (played by James Earl Jones) turns into a snake to emphasize his inhumanity, though Conan doesn't actually fight him in that form.
At the end of the stop motion film, Jack the Giant Killer, after several attempts to kill Jack (the main character) are foiled, Pendragon, the main villain and evil sorcerer, transforms into a dragon to fight Jack, who eventually kills him in the final battle.
In Return to Oz, once Dorothy begins guessing right at the ornaments and restoring the Scarecrow, Tik Tok, and Jack to their original forms, the Nome King, previously human-sized and at one point almost looking entirely human, becomes a giant rock monster and attempts to eat them all. Unfortunately for him, Billina was inside Jack's head, and laid an egg, which fell into his mouth... POISON... TO... NOMES!!!
At the end of the first Guyvermovie, Fulton Balcus, the head Zoanoid, turns into a giant creature after the main character refuses his invitation to join Chronos. The transformation is shown in the dark. All you can see are his Glowing Eyes of Doom, as they raise and separate to show just how big he has become. To his credit, taking him down requires the Guyver to use his secret weapon - a Wave Motion Gun in his chest.
In the sequel Guyver 2: Dark Hero, Crane, a reptile zoanoid and main antagonist, gets his own (though damaged) guyver unit and turns into bad-ass incarnate.
At the climax of All Dogs Go to Heaven 2, Red assumes his gigantic true form after capturing all the dgos in Heaven with Gabriel's Horn. Truthfully, it's just an incredibly massive and more demonic version of his base form, but is still enough to prove a major problem... until Charlie discovers his weakness.
During the final battle of Ultra Galaxy Legend The Movie, Ultraman Zero manages to defeat Ultraman Belial by throwing him into a pit of lava. He's soon followed by the souls of his 100 kaiju, merging with them to form the 100 Union Kaiju Beryudora. It takes an all out attack from the Ultras, EX Gomora, and Ultraman Zero to finally put him down. And Belial still survived!
Literature
The Chronicles of Narnia: In The Silver Chair, Prince Rilian expresses relief that The Vamp who'd kidnapped him turned into a giant serpent when she tried to kill him, because he never could have killed a lady (but had no problem slaying her as a serpent).
Given that she had literally put him through Hell for so long, it's a wonder that he didn't take exception to his rule and just outright kill her in her human form. We can't know for sure what he'd have done if she hadn'tScaled Up, of course, but given that he'd just practically allowed her to brainwash him again it doesn't look good...
And an interesting twist from Night Mare, book 6 in Piers Anthony's Xanth series: the protagonist, Mare Imbri, literally is a "Night Mare." When, in a climactic scene, she confronts a shape-shifting villain, he almost saves himself by shifting from human form into horse form. Imbri does eventually defeat him, but it becomes much, much harder to do so. It isn't just because she can't hurt a fellow horse either, it's because she's in heat at the time. (Sigh, Piers Anthony...)
In The Dresden Files, Red Court vampires can either take the form of beautiful young men and women... or hideous black rubbery bat-creatures. Note that the human form is an illusion, which is bad news for anyone who's infected.
Also, this is explicitly the main power of the Knights of the Blackened Denarii. They change from human into some horrible form for combat, with a twisted Angelic rune on their forehead and a second set of eyes. So far we have seen: A snake-man, a medusa-haired human/panther thing, a six-legged horned fanged bear, a normal human with a shadow that will strangle you, an obsidian statue, a feathery tentacled thing, a praying mantis with little praying mantises for blood, an emaciated grayish spiny humanoid, and various forms of big and ugly and scaly and hairy.
Interestingly, Nicodemus (the head Denarian) explicitly does not have a One-Winged Angel form- both because he's The Chessmaster by nature and would rather put his power into abilities other than raw strength, and because of the fact that between the Artifact of Doom hangman's noose he wears (which makes him immune to conventional attacks) and his own skill as a warrior, even his base human form is capable of overpowering just about anything if need be.
In James Swallow's Warhammer 40,000Blood Angels novel Deus Sanguinius, Arkio starts to metamorphise under the influence of Chaos. Inquisitor Stele can contain it, but at the climax, fighting Rafen, he starts to bleed black blood, and then to change in form. Rafen shows him himself in a mirror and he breaks it in rage. Then the Spear of Telesto rejects him.
There's something of a sort like this in American Gods, as the deities seem to have a form that shows one of their believers whose faith was strong enough to make them real. Thus, Mr. Nancy/Anasi has this form of an African boy with a distented stomach and infected leg and Hinzelmann shows a child pierced by swords, which actually reflects his being created through human sacrifice. Interestingly, The Other Wiki novel for the character indicates that this was actually that character's true form in the original stories.
In the Dark-Hunter series by Sherrilyn Kenyon, the leader of the Dark-Hunters, Acheron, is in actuality an Atlantean god. This means that if he's pissed beyond all hope of redemption, he turns blue, gets black horns, nails, and lips, and basically rips the ever-loving everything out of most everyone. Bonus points for the ability to end the world should he go visit his mother in Atlantean Hell.
Visser Three used dozens of these over the course of the series, rarely using the same one twice. Fridge Horror ensues when you realise there are species of these for him to acquire DNA from.
Also, you realize just how awesomely Badass V3 is: you can only acquire DNA while in your native form, and while Andalites such as the one the Visser possesses have the slashing tail of doom, that'd barely inconvenience some of the nastier beasties the Visser has turned into - some of whom have projectile attacks like fire and venom and spears. A centaur with a pointy tail managed to get close enough to these things to actually touch. (Yeah, acquiring puts 'em into a trance... but you gotta touch 'em first.) One of them was actually a natural predator of his race, evolved to remove Yeerks from their hosts to eat.
In the finale of book 2, Fablehaven's artifact is guarded by a seemingly harmless cat. When you kill it, it is resurrected as a larger cat. This happens seven more times, until it has become a winged, three-headed, three-tailed monstrosity with snakes sprouting from its back that shoots acid.
When Gavin (a.k.a. the demon-dragon Navarog) scales up into his dragon form.
Happens at the end of Curse of the Azure Bonds. Final bad guy Phalse goes from a mostly unassuming Halfling into a big Beholder with teeth stalks instead of eye stalks.
And again in the sequal, the Wyvern's Spur. For the final battle, the hero polymorphs into a wyvern, and the villain into a dragon.
Justified in the book Coraline since as Coraline collects the children's eyes, Other Mother's power fades it causes Glamour Failure.
Black-haired, black-eyed, black-garbed Willow at the end of season six could definitely be said to be at least partially this.
Heck, all of the vamps are examples to a degree. They just need to put their "game faces" on.
Without their encounter suits, the Vorlons of Babylon 5 look like holy creatures from the observer's mythologies. But when angered, they look... different...
Let's not forget Power Rangers: "Make My Monster Grow!". Every Super Sentai/Power Rangers season except for Himitsu Sentai Goranger and J.A.K.Q. Dengekitai has had this, with each Big Bad using a different growth method. Also, growing comes with different other advantages for the monster: sometimes any damage taken or weapons lost while small will return (including whatever you broke to shut down its main means of terrorizing the populace. Uh-oh!), and sometimes it will gain a new form much like a Big Bad can. Power Rangers Lightspeed Rescue has the latter happpen often. Sometimes, entirely new powers are gained.
Probably the uber-example would be Season 1's Scorpina. Whenever she grew she went from a pretty Asian woman to a hideous scorpion creature.
For quantity, several Big Bads tie with four advanced forms. Most recently, Dai Shi has human form, Lowemon-ish lion armor form (with similar transformation!), Phantom Beast King form, and eight-headed dragon form (his true self, as seen in a carving at the beginning of the series.) He's not alone, though: Ecliptor, Trakeena, and Olympius can boast the same number of forms.
Dai Shi's sidekick Camille has three forms: human, armored, Phantom Beast General.
In the aforementioned Lightspeed Rescue, in a few cases, the monsters have to grow twice to fight the Supertrain Megazord, which is a good two or three heads taller than the average giant monsters.
Also, some of the more powerful wizards can take on monster-like People in Rubber Suits forms of their own. Two in particular have rubber suit and Ranger suit forms.
A similar thing happens in Power Rangers Jungle Fury. The Zords are actually manifestations of primal spirits unlocked through martial arts.
Power Rangers Operation Overdrive has it like it's going out of style, with Moltor being the only major villain to have just one form. Namely:
Flurious gets the MacGuffin in the end, turns into something that looks like a chess piece or a Monster Pope, and freezes the planet.
Miratrix turns into a monster bird with the power of the MacGuffin of the week and completely manhandles the Rangers' strongest machines. Unfortunately for her, Ronny and Tyzonn are able to remove the MacGuffin from its place before she can finish the Rangers. (In Super Sentai, this was the One Winged Angel form of another villain who isn't in PR. Mira's counterpart Shizuka had a different OWA form.)
Kamdor... can open his faceplate to show a different faceplate. Kind of a letdown after Miratrix's transformation.
The two main Fear Cats use Flurious' technology to go from feline monsters to awesome black-armored gun-toting warriors, a permanent upgrade.
In Power Rangers In Space, the Psycho Rangers didn't have Zords, instead transforming into giant monsters. This is the same series with Ecliptor's four forms, and Darkonda's three: standard Darkonda, Darkliptor after absorbing Ecliptor, and a powerful but insane form he mutated into after taking a strength enhancer that had been poisoned by Ecliptor for the Darkliptor incident (not to mention separating from Ecliptor and using him as a shield once the fight went bad.) The poison seems to count as Cursed with Awesome, though: after seemingly being taken out by, but soon recovering from, the Megazords' first finishing move, he's suddenly much saner and still ultra-powerful.
Power Rangers Dino Thunder makes a habit of it, too. Mesogog turns into a monster that is very strong and separates into five. Zeltrax uses a mystical 'tree of life' and gains a second, thorny form - and as a case of We Can Rebuild Him, Zeltrax's standard form may count as the OWA form of Terrence Smith. The White Ranger clone has access to the same Super Mode as the good White Ranger, and Elsa... does returning midseason with a new haircut, and inexplicably stronger count?
Kamen Rider Den-O and Kamen Rider Kiva had monsters occasionally assuming gigantic monster forms (dubbed Gigandeaths and Sabbats, respectively). This typically only happened when they needed to show off the newest Den-O form's Cool Train car or Castle Dran. CG costs are expensive.
Kamen Rider Black: The High Priests sacrifice the stones keeping them alive to complete Nobuhiko's transformation into Shadow Moon. He then rewards them by powering them up into Great Mutant forms and making them his lieutenants.
Some Orphenochs in Kamen Rider 555 can also take on advanced forms. There are no giant-sized vehicles to deal with them (though the vehicles they do have are quite weapon-laden and sometimes extend/expand. However, these are not typically used for giant monster-busting; more for faster or more numerous enemies, or for when you really, really want a rival Rider dead.)
Throughout Kamen Rider, there are many monsters who are humans/former humans who can power up, or are monsters hiding as humans (still this trope; hence its alternate title "Behold My True Form.") Basically, every Orphenoch, Fangire, Worm, Dopant, Greeed, and so forth is this.
The pre-Power Rangers sentai series Choujuu Sentai Liveman has this because of the "better living through mad science" ways of the villain organization. Remaining a puny human will never do, and nor will failure to upgrade a monster or cyborg form that has proven ineffective. That's why the generals all have multiple forms. As of 38 (as far as has been English subtitled) Kemp leads the pack, going from Kenji to Dr. Kemp to Beauty Beast Kemp to Fear Beast Kemp. (He got a head start, beginning the series with his "Dr." and "Beauty Beast" forms, whereas the others' "Dr. [name]" forms were pretty much all they had.)
However, the Big Bad of Jungle Fury's parent sentai Gekiranger has a doozy: Rio (lion armor guy) doesn't have the dragon form because that came from Gekiranger baddie Long. Long goes from a boyish young man to a Phantom Beast General form, fair enough. However, when he reveals that yes, he is the Big Bad, and only wants Rio to become the Phantom Beast King so he'll go out of control and destroy the world, and that fails, Long takes on his true multi-headed dragon form. And for the teamup with the following series, Engine Sentai Go-onger, Long returns and eventually possesses the Monster of the Week, Nunchuk Banki, to become Long Banki. So ultimately, he's got as many bodies as Dai Shi.
As with Super Sentai and Power Rangers above, the human commandants of the terrorist organization Shocker in the original series had monster forms.
In Kamen Rider Dragon Knight, the Mooks did this. It didn't do them much good. A flashback reveals that the advancedMooks can become more-advanced, flight-capable ones. It...still didn't do them any good, but hey, what matters is that it looked awesome. The last two or three episodes give us all three types of cannon fodder as well as various monsters in an all-out war against the Riders.
It is a tradition for the more recent Rider series (Den-O, Kiva, Double, and Oz) to have the monsters do this. The only one to break the sequence was Kamen Rider Decade (released between Kiva and Double), which makes up for it by having the good guys do it — FINAL FORM RIDE.
Kiva himself was able to do this by transforming into his dragon-like Flight Style form, which did give him a huge boost in power.
A few main human villains eventually do this in order to reach their goals. Tennoji in Kamen Rider Blade fuses himself with the artifical Category Ace Kerberos in order to try and win the Battle Fight himself. In Kamen Rider OOO, Dr. Maki absorbs five Purple Core Medals to mutate himself into a Greeed, completing his transformation in episode 42.
In Spearhead from Space, the Doctor Who serial that first introduced the Autons, the creatures themselves look like mannequins unless tweaked to look (mostly) human; however, their leader gestates into the Ultimate Form with which to Take Over The Earth. It is... a giant, tentacled squid.
Ah, no. The tentacled squid is called the Nestene Consciousness, a creature with an affinity for polymers and plastics (or, if the Ninth Doctor is to be believed, the byproducts of making said plastics). The abomination described is its true form. It's established that it arrived in a meteorite shower—the phrase "some assembly required" seems apt—and each meteorite, containing a part of the Consciousness, animated the mannequins/dummies created by Auto Plastics (hence, "Auton") and gave them the mission of collecting the rest of the meteorites. In other words, it possesses plastic products. The monster itself was in some kind of an incubation or life-support chamber, waiting for the rest of its "bits" to arrive. Of course, by the time of "Rose," the Consciousness had lost its squiddishness, and resembled a big face in a vat of molten plastic, apparently having lost its physical form in the Time War.
Subverted in The Satan Pit, where the Doctor finally encounters The Devil, a monstrous horned creature the size of a skyscraper, only to discover that it is only a shell, as the Beast's essence is now in a regular human.
Played straight by the Professor Guinea Pig in "The Lazarus Experiment", who winds up as a freaky scorpion thing.
In the spinoff Faction Paradox series, the more the Time Lord Expies regenerate, the more like this they become until they're nothing but sentient masses of weaponry and defensive devices. You wouldn't like to meet 'em.
Ganger!Jennifer from "The Rebel Flesh"/"The Almost People", who goes from seemingly human to a loping, four-legged monster.
Beetleborgs has had its share of transforming baddies. Kind of odd, given that many of the good guys were already monsters.
Noxic in the first season had a super form called Hurt-Ulyles, in one episode Fangula the resident vampire became Super Fang and in Metalix- The Crustaceons themselves have this.
In the episode Buggin Out which is a satire of the 80's remake of The Fly Flabber sees a drawing of a matter transporter, brings it to life and tests it out- but unfortunately much like in the movie a fly monster called Kombat Gnat gets in the machine with him- and when he arrives at Zoom Comics he's merged with the creature and gradually evolves into Kombat Gnat and the kids have to fight him in order to get him back to normal.
The Man in Black/Jacob's Enemy on Lost has quite a doozy of a final form: the Smoke Monster.
Though in reverse. He is able to take this form throughout the entire series except during the finale battle, since he became mortal again which was required to do so in order to kill him.
The Wraith from the Stargate Verse have very versatile organic technology. Even their ships are alive but are restricted by their power generation capabilities. In the final episode, one Wraith got the right idea and wired the most potent energy source in the known universe into a Hiveship (Wraith equivalent of The Battlestar). It used the extra energy to grow more armor and guns, resulting in a HUGE (3200+ meter long) monster of a ship armed with dozens of cannons. Asgard plasma beam weapons which could easily neutralize a normal hive in about half-a-dozen shots barely even scratched the Superhive. Not to mention the increased sensor sensitivity...
(the team is scouting the superhive with a cloaked jumper) McKay: Hold on, they're powering weapons... Ronon: They can't see us, right? McKay: No, of course not. They must be just running a test- (a shot passes VERY close) Holy crap... Sheppard: What are the odds of them randomly firing a test shot DIRECTLY AT US?! McKay: I'd say: given the enormity of space all around us, non-existent?!
They managed to take it out only by sneaking a multi-gigaton nuke inside but still.
Zogu, the Big Bad of Ultraman Gaia first appears as an angelic entity to trick Gaia and Agul, then defeat them. When round two comes around, they're ready for his tricks and beat the tar out of him. In response, Zogu undergoes the reveal your true form version of this trope and turns into an absolutely massive, centaur-like beast that can crush skyscrapers under his feet. After a lengthy fight, he's finally killed by a combined beam attack but keep in mind, Gaia and Agul were supercharged with the power of Earth's monsters and at their strongest at the time.
Music
The concert is over. You have just confronted the most sublime manifestation of avant-garde classical music. You survived its tone clusters and polytonality. The thundering dissonance and disharmony begin to fade away from your aural registers — and with that, a new appreciation for sound in all its forms sets in. Out of respect for the sheer artistry of the pianist, you and the rest of your party begin to clap. The pianist, exhausted of his repertoire, walks back out onto the stage to bow to the audie—wait, what. What is he doing? Oh—Oh God. Oh God. He's come back. Oh God. He's returning to the piano.
A particularly appropriate example — Henry Cowell's Dynamic Motion is considered a rather... out-there piece of avant-garde piano, described as an act of "pianistic violence". This alone would make a suitable BGM for any RPG final boss battle music... Then you have the Four Encores to Dynamic Motion. The fourth, Antinomy, is just asking to depict a scene where a slain alien horror resurrects itself out of its own corpse as a distorted choir sings its glory in the background.
Michael Jackson pulls this off with great effect in his music video Ghosts as the Maestro. He also does a pretty good Demon Head near the end.
Professional Wrestling
After losing a match against Evolution in 2003, the "Big Red Monster," Kane, was forced to permanently remove his trademark red-and-black mask. This resulted in audiences seeing his true face for the first time since the character's debut six years earlier - despite allegedly having been severely burned in a fire, Kane's face was not covered in scars as he claimed; he was simply that insane. Now that he could no longer hide his "disfigurement", Kane became even more psychotic and dangerous than before.
Japanese pro wrestling loves this trope. Most notably is Jushin "Thunder" Liger, who, during intense rivalries, sometimes transforms into the more aggressive, much more evil looking "Kishin Liger". Also of note is Bx B Hulk, a normally upbeat gimmick about dancing, turns into "Killer Hulk", adopting an all black costume and evil looking facepaint.
A lot of Hindu deities have avatars that basically serve this purpose. Kali, in particular, is a terrifying and destructive (but not evil) form the warrior-goddess Durga assumes to deal with the extremelypowerful demon Raktavija. Itdoesn'tendwell.
Jesus, in the Book of Revelation- particularly chapter 19, where he shows up as a Warrior Prince with flamingeyes, surrounded by Instant Runes and riding a white horse at the head of a legion of angels. He spits a burning sword out of his mouth, summons an army of carrion birds, and proceeds to lay the smack down on the various monsters, demons, and false prophets that had been corrupting the earth and fighting with his forces for the previous couple chapters.
Stand Up Comedy
Bill Cosby 's wife does this in one of his standup routines when she notices that Bill fed the kids cake for breakfast. Her face splits in half and she gains the ability to shoot fireballs from her eyes. Then She screams "WHERE DID THEY GET CHOCOLATE CAKE FROM!?!?!?!?!?!?!"
Tabletop Games
In Warhammer and Warhammer 40,000, warriors of Chaos can be blessed or cursed with "gifts" from their patron Gods, turning them steadily more inhuman. Eventually, at a certain point, the weak-willed become mindless Chaos Spawn, while those with Villainous Willpower ascend into Daemon Princes who retain their sentience and control over their vast powers. In either case the warrior now becomes a full Daemon extra vulnerable to anti-Daemon abilities and armament.
GURPS alows a player to build their own version with the alternate form advantage.
Ragnorra, the obligatory Body Horror entry from Elder Evils, transforms from a bloated blob of wormlike flesh into a curiously human face made out of strands - her True Mother form. While spawning utterly abhorrent monstrosities that simply should not be.
Erwin Stahler from Mutant Chronicles starts out as a human-sized model on the battlefield, but once he's down, he goes One-Winged Angel and turns into a bigger, armored mutant with big honking claws.
In Exalted, there is a powerful necromantic spell named the Birth of Sanity's Sorrow. It is cast at the moment of the necromancer's death, which transforms their dying corpse into a titanic monstrosity of grotesque design, inspired by the necromancer's delusions and nightmares of dead principles. Fortunately, BoSS is usually only accessible to boss-level NPCs.
The errata document for the game includes an upgrade to the stats of the Unconquered Sun as he appears in the "Glories of the Most High" supplement that gives him an enhanced form called "Magnanimous Unbound Sun" that gives him an extra couple hundred health levels, an extra 28 arms, some healing powers, and the inability to be killed unless this enhanced form can be dealt with.
The Sorcery spell Incomparable Body Arsenal turns the caster into a Humungous Mecha.
Other powers that can cover this include certain Lunar Knacks and Infernal Shintai Charms.
The Infernal Shintai Charms are augmented by the Charm Driven Beyond Death. Basically, when an Infernal hits the Incapacitated Health Level, they make like they're downed (like, say, going down on one knee). Then their anima banner erupts, and they have one turn where they're completely untouchable but can only activate a Shintai Charm. At that point, they reenter battle with their Essence pool somewhat refreshed... and at the end of the battle, they have to roll not to keel over regardless.
The Shintai charms, explained in further detail: The most minor ones for physical changes turn you into a version of you crafted from red mist (Scarlet Rapture) or sand (Soul-Sand Devil), can split off a mortal clone of you (Splintered Gale), or allow you to copy someone else (Black Mirror). More extreme ones give you a constellation of crystalline orbs (Heuristic Logos). The most one-winged of them are Tenebrous Apotheosis (which ramps you up to become pretty much the Ebon Dragon), All-Devouring Depths (which turns you into a shoggoth), DEMON EMPEROR (which turns you into a walking Ground Zero), Greater Shintai of the Endless Desert (which quite literally turns you into a living geographical feature) and Devil-Tyrant Avatar (which allows you to string together mutations to build your own form). Of these, only Soul-Sand Devil and Splintered Gale can't be used as a rude surprise in combat, and that's only because one is permanently in effect and the other is used to create mortals, although one odd Splintered Gale build theoretically allows you to mass-produce cloned suicide bombers.
Averted with Asmodeus in Dungeons & Dragons: While his true form is apparently a giant primordial serpent of some sort, the rules given for fighting him - as unlikely a situation it would be to fight the super-intelligent, scheming ruler of all Hell - only describe fighting him in his humanoid devil form.
Presumably because, against a being to whom the word "god" would be an insult, your party wouldn't stand a chance.
Demon The Fallen gives the titular Fallen "apocalyptic forms," echoes of their glory from when they served Heaven. Each form is based off of a primal incarnation of the Lores the angel knows; therefore, a Devil in the mold of Lucifer could have an apocalyptic form that's either a pillar of fire or a glorious, shining light, and a Devourer could have an apocalyptic form that's either a man with the head of a lion or the perfection of human flesh made manifest. But if the demon's weighed down by Torment, well... expect the apocalyptic form to look honked up.
In addition, the Old World of Darkness has Werewolves and all the other Fera, all of whom can take a nightmarish warform when they need to kick some tail. Vampires also have access to some nasty disciplines that let them do this, such as Zulo Form of Vicissitude, the armor of living shadow of Obtenebration, the War Form of Protean and Serpentis.
The Neo Pets' web-based RPG parody/thingy Neo Quest II has the final boss "defeated", then returning with a few additional immunities, double the HP, and a double-sized graphic. And additional limbs, wings, spikes, and menace.
Square Enix
Square Enix probably loves this trope even more then Disney does. It's almost a rule that Square-Enix games MUST have a giant transforming final boss(if that was not already evident from the fact that it has its own dedicated huge category).
The Trope Namer is Sephiroth from Final Fantasy VII, who had either three or four forms depending on how you count (angel wings factored heavily into the changes, hence the title of the BGM and this article, although there's actually more than one in most of 'em), as well as Jenova in her various mutant alien forms, Hojo turning himself into several different mutated monster forms before dying, Vincent Valentine having four different forms as his limit breaks, and if you really want to look too deeply at things, the WEAPO Ns can be seen as the Planet's own attempt at a One-Winged Angel.
Also, his name translates to One Winged Angel in latin, hence why the Ominous Latin Chanting in One Winged Angel constantly repeats Sephiroph. So this pretty much does describe Sephiroph perfectly
Final Fantasy IV had Zemus the Lunarian wizard transform into the demonic insectoid Zeromus, which transforms into a more boney form when the heroes shine the light of the Mineral MacGuffin on him. Various bosses also do similar things- the Asura and Leviathan transform from human to, well, Asura and Leviathan, a human boss turns his arm to snakes, the Dark Elf transforms into a dragon, and several monsters show up on the map as hooded, cloaked figures, although if that is actual transformation or weird map sprites is unclear.
FFV had Exdeath twice, first into his true form of an evil tree, and then into a hodgepodge of various monsters out of the Void when he learns that Evil Is Not a Toy.
Also Gilgamesh, who gets extra arms and more demonic looks.
FFVI had Kefka (who had angelic wings in his final form, along with diabolic wings, and a pair that was a fusion of the two. This was probably a play off of Christian angelic mythos (Seraphim have six wings), designed to further highlight Kefka's actually being God (capitalization intended) at that point. The heroine Terra also has her own transformation, where she invokes her Esper heritage and gets purple glowy fur.
Final Fantasy VIII had the fake president turn into a zombie. And Ultimecia, who just gets weird looking.
Final Fantasy XI is a bit more reserved. The Shadowlord and Promathia (initial release and second expansion) have two-stage battles, but rather than undergoing a physical change for the second stage, they just get a new set of abilities and a fresh HP Bar.
The third expansion features three bosses back to back in the final battle, though the final one, Alexander, pretty much takes over the fight himself after you deal enough damage to the Prince who is piloting his current body. This is played a bit more straight in the first expansion, Rise of the Zilart when Eald'narche is knocked off his floating platform and his eyepatch comes off, revealing a glowing eye and he starts flying for the rest of the fight. What Lady Lilith and Atomos are up to in Wings of the Goddess remains to be seen.
Final Fantasy XII had Vayne turn into a gigantic clockwork dragon with the help of his rebel Occuria pal.
Final Fantasy XIII features Galenth Dysley, who masqueraded as a frail old man and the leader of the Sanctum. His true form is the giant-robotic-rape-face fal'Cie Barthandalus.
Orphan, the true final boss, has his own one-winged angel form. Which makes it a one-winged angel form of a one-winged angel form.
Crisis Core is quite possibly the hugest example of this trope. Two of the four main male characters become literal one wing angels - one of which is black-winged and the other is white-winged. (One of the ones who doesn't is Sephiroth - he saves it for the next game.) There are even several varieties of mooks and monsters who suddenly get one wing blooming out of their backs (they're genetically derived from the abovementioned two), ''all'' of which who can apparently fly with only one big, feathery wing. The second half of the game feels like the monsters from the first half decided to reappear after having visited a grand Unpaired Attachable Wings clearance sale. It reaches a point where you expect everything that isn't a robot to have a bizarre feathery wing graft. In fact, the protagonist you play as should logically at some point sprout a wing as well. Thankfully, he saves it for the ending cinematic.
Angeal, who gets his One Wing very early, apparently is annoyed at all the competition - when it comes time for his boss fight, he goes back to basics and mutates himself into a horrible, monstrous chimera. With one wing. Then again, he was doing it explicitly to force Zack into killing him, so... this one's kinda meta.
In the Dissidia: Final Fantasy games, every character has an "EX Form"; for many of the villain characters, it's their One-Winged Angel form. Kefka, for instance, gains his 'God of Magic' appearance, and the Emperor assumes his 'Emperor of Hell' form. Ironically, as a result of loading issues, Sephiroth doesn't assume his 'Safer Sephiroth' form from his game, instead taking on his Kingdom Hearts single-black-wing look. Similarly, Exdeath doesn't use his Neo form as his EX Mode. Instead, it shows up as an alternate costume in the prequel. Its default setting is based on artwork - when it goes EX Mode, its colours change to match the actual game sprite.
In Dirge of Cerberus Azul, one member of the Super SoldierQuirky Miniboss Squad is on his own a pretty large bruiser who hefts an assault cannon, but on top of that he can turn into a literal Behemoth for extra headaches. And unlike traditional Boss Encounters, he can switch between them at will.
The original Final Fantasy Tactics's entire villainous cast did this, with a Zodiac theme, giving at leastsixOne-Winged Angel forms The final boss does this as well, in typical Square fashion.
In Final Fantasy Tactics Advance we have Queen Remedi, who turns into the Li-Grim, the spirit of the book and responsible of changing the world.
In the final battle of Final Fantasy Crystal Chronicles The Crystal Bearersthe big bad fuses with an airship and transforms the ship into a giant red crystal. At the same time the main character follows this trope more literally when his telekinetic powers manifest themselves as a blue surfboard thing, some sort of face guard and a giant blue wing.
Sheex, Fahna and Thanatos all do this in Secret of Mana. Geshtar might also qualify since his boss form, though clearly humanoid, is classified by the game guide as being robotic.
All the Bosses in the Romancing SaGa Trilogy had this: Romancing Sa Ga Saruin had 2 forms: His second being his upper half of his body sticking out of a sphere while he grew extra appendages to his torso and back (in the remake anyway). Romancing Sa Ga 2 The 7 Heroes gradually joined the amalgamated form every 6,000 HP dealt.Romancing Sa Ga 3 The final boss: Destroyer changes to a more crazed, shinier form with more wings that could also change into four other forms representing the four Devil Lords, but only if the form chosen was that of a Devil Lord not defeated. The protagonists can transform too.
Ah, Kingdom Hearts. In the second, Xemnas fights you as himself, as a spaceship, as a suit of armour hurling everything he can at you (including the landscape) while sitting on a throne, himself again with different powers and a zebra suit, and very likely some other things we've forgotten.
The fight against Ansem has multiple phases, but he actually transform until you reach part 4 of the fight. Departing from the usual thing with bossess transforming, people tend to find his form when he first possess Riku harder, and his final form to be a pushover.
The Xemnas battle has eight phases: the first rush to the spaceship, the second rush to the spaceship, the spaceship engines, the spaceship core, Xemnas on the throne with a big sword, the Xemnas dragon, Xemnas on the throne again, and Zebra Xemnas. Unlike his Heartless counterpart, Xemnas doesn't actually physically transform: he simply goes through several different outfit changes and makes use of his Dragon-esque space ship. This is presumably because only the most powerful Nobodies can maintain a humanoid appearance, so by not going all Eldritch Abomination on us, Xemnas is actually setting himself apart from the average mook. (Of course, What Measure Is a Non-Human? still kicks in. Due to the whole Nobody thing.)
It also features quite a few of Disney's One Winged Angels, notably Maleficent and Jafar.
358/2 Days brings us a One Winged Angel form for Xion. It's...rather difficult to describe...It's sort of like an armored monstrous Nobody form of none other than Sora. Interestingly, this is the form the boss assumes for all four phases of the fight, with each phase bringing new weapons rather than new transformations and the final phase bringing a bit of a growth spurt too.
Birth By Sleep notably doesn't do this. Every character's final boss remains human. Vanitas simply takes off his helmet and pulls out a different keyblade for his 2nd stage; Master Xehanort migrates into Terra's body, with the player taking control of Lingering Will for his 2nd fight; Terranort, the True Final Boss, simply summons Xehanort's heartless familiar from Kingdom Hearts for his last battle; and for Aqua's story, the final bosses are two different characters.
In Super Mario RPG (co-developed by Squaresoft), Final Boss Smithy gains several forms after fighting with it once. The first looks like an evil bearded robot with a hammer. The second is the same robot, except with a giant skull for a head which can be switched to four alternate forms.
Also, the Czar Dragon turns into Zombone.
Seiken Densetsu 3, all 3 of the final bosses transform into giant monsters before you fight them. One of them has two forms you fight, though to avoid scarring anybody, his two forms collectivily about as much HP as the other two bosses.
Likewise in Secret of Mana, only you never fight the human bosses in their normal form; instead they tend to go One-Winged Angel right from the start. Even Big BadThanatos ends up becoming the Dark Lich for his fight.
Legend of Manadoes have human bosses, and they're much harder than the One-Winged Angel bosses due to being smaller and faster.
Chrono Trigger contains at least four instances of this, in various forms: Masa and Mune combine to form a hulking beast, Queen Zeal becomes a giant, crowned mask and gloves with increased magical power, and Lavos does it twice.
The 'Dragon of Fire' fight in Chrono Cross. While the first time you fight him he's fairly small and humanoid, partway through the second fight he will change into an even larger (and cooler) dragon in the style of muscle growth.
Parasite Eve has this for Eve, the main antagonist. She starts off by possessing the body of a woman, changes into a slightly disturbing form by having a giant fin instead of feet, long arms with sharp claws, and crazy hair. By the time you see her near the end of the game, she becomes a multi-breasted bloated monstrosity as she prepares to give birth to the Ultimate Being, which changes slightly when you fight her for the last time, but she also changes form from here by becoming an almost angelic figure once her HP gets low enough.
The protagonist accomplishes this as well in the first game, with her ultimate attack(of the two pure attacks in the game)'Liberation', the form being quite literally angelic, but in a biological manner. And of course, the 'secret boss' from the first one manages the -same- form. Only she remains in it throughout the fight.
The sequel also has the final boss look and fight in a similar way as Eve's final form from the first game.
Guildenstern in Vagrant Story is a textbook example. He turns black, spouts wings, merges with the game's main religious symbol to turn into a giant cross-shaped... bug... thing, and flies around casting things with names like "Judgment" and "Bloody Sin".
The World Ends With You beats Sephiroth out in both religious symbolism and overkill on its Final Boss forms for its Big Bad: He turns into a giant serpent and then fuses with Joshua who was making some sort of cross, after which he turns into a five headed dragon that takes up the majority of both screens while holding your other two partners in his claws. In fact, most of the bosses turn into Noise during their boss fights.
It's pretty much a tradition in the Dragon Quest series for the final boss to have more than one form, starting with the Dragonlord/Dracolord/King Dragon in Dragon Quest I. To date, the only two final bosses in the series that don't follow this trope are Malroth in Dragon Quest II and Zoma in Dragon Quest III.
Dragon Quest VII is an unsual example in that while the final boss is a four-stage fight, only the second stage is a One-Winged Angel. Third and fourth stage are the final boss melting.
Special mention must also go to Dhoulmagus of Dragon Quest VIII, who is a mid-boss who does this.
A particularly odd case was the final boss of Dragon Quest IV, Psaro the Manslayer, having discovered the secret of evolution gradually loses body parts in the first half of the fight, then grows new limbs, ending with a completely different form from his first, which was itself completely different from his human form, and eerily similar to a previous boss, complete with new battle music.
Drakengard has two examples: Manah, when the gods give her a Villain Override, and Furiae, after being placed inside a Seed of Resurrection.
Loki goes into One Winged Angel mode before he fights Lucian, and then again during the A ending events, you never get to fight his original form though.
In Bahamut Lagoon, Alexander does this. He's already a massive dragon by default, but after killing him, a dozen of the creatures that are used for vessels of reincarnation for dragons rush into the room. He ends up coming back as a multi-headed monstrosity that takes up half of the map.
Video Games
Every boss does this in Yoshi's Island. You don't always fight the first form, actually. Usually you just see the "normal" size boss and then Kamek comes in and says something, then puts rainbow dust on the boss to make it grow, which initiates the fight. Bowser gets the biggest tune-up at the end when you fight his normal baby form, and Kamek makes him several times larger than any other boss so far.
Kamek reprises this "making bosses bigger and more powerful" role in New Super Mario Bros Wii, in which you do fight the smaller versions first. And once again, after you fight Bowser in the classic Super Mario Bros. fashion, Kamek makes him probably even larger than he did in Yoshi's Island. Bowser is pretty much the size of three quarters of the screen while your players are the size of one of his claws, at best.
Used in an interesting way in Temple Of Elemental Evil. Towards the end of the game, your party can encounter a human adventurer deep inside one of the Elemental Planes. She explains that she came down there with her party, but they were killed and she barely escaped. She asks to go with you, and if allowed you'll find she's a decent-ish sorceress. But if in dialogue your characters detect something amiss, they can confront her about it. At this point she reveals that she's actually a half-succubus, and wants to come along with the party because she's bored. If you let her, she'll drop the pretense and switch back into her true form, making her a much more powerful companion.
Naturally parodied in Barkley, Shut Up and Jam: Gaiden. The first form is already one-winged. So what happens when it's time for its true form? A dinosaur with Barkley's face on it. And not just any dinosaur, but the body of Diablo from Primal Rage!
Dracula fills this role to the letter in almost every Castlevania game. In this series, he's more of an ultimate evil rather than just some vampire. See the quote at the top of the page.
The Symphony of the Night version is actually Dracula in his throne still, but the throne itself transforms. Lazy bastard.
Also, upon closer observation, the HoD incarnation seems to be a giant amalgamation of Dracula's relics. Note the beating heart and the single eye that tracks you, and so on - all six relics are in there somewhere.
Castlevania 64 has him turn into some kind of 50-foot dragon/centipede hybrid. The game as a whole wasn't the greatest, but you will say Oh Crap the first time you see Drac's final for. And that's before he starts throwing miniature H-bombs at you...
In Portrait of Ruin, Dracula fights you with Death at first, then after beating on one of them for a while, he uses Soul Steal on Death himself, absorbing him and turning into a giant demon.
In Order of Ecclesia, this is notably avoided for the first time in decades, as the entirety of the final battle against Dracula is fought against the dashingly-handsome vampire we've known for so long. this may have been from the fact that the player is holding half of Dracula's power in the form of Dominus, which must be used to end the battle, but not before beating on Dracula for a good long time.
Super Castlevania IV did something like this as well, but as his health neared its end, Dracula's abode starts crackling with electricity again and pulses a red glow, and Dracula's head gets replaced with a demonic SKULL. This is when he starts breaking out the scary flashing lightning.
Rondo Of Blood, and by extension the Symphony of the Night prologue had Dracula become a huge demon that bounces slowly and isn't that hard. It's reused also in Dawn of Sorrow's Julius mode, where Soma gives in to his powers. While the first form is classic Dracula but using soul powers, the second form is the Rondo Of Blood one, except much more dangerous as while he leaps, he uses various other soul abilities. Rondo's remake in Dracula X Chronicles has Dracula fight you with wings in his normal form AFTER the One-Winged Angel form.
And for the times when Dracula wasn't the final boss? Death took over in Lament of Innocence; Graham pulled a mutilated abomination throne on us akin to Symphony's Dracula; Chaos showed that it was a black orb with pulsing black prominence flares inside of a really chaotic room; Menace unrolled into a golem made of souls.
Death does it a few times. In Symphony of the Night, he turns into a scythe like skeletal creature, in Circle Of The Moon he turns into a turtle thing (?!), and in Harmony Of Dissonance, he turns into a skeletal train with a skull and claws that floats around the screen.
Various other bosses sometimes have multiple forms. Examples include Camilla and Olrox Whether the first form is fought or not is a case by case basis.
Parodied in the patchwork freeware game I Wanna Be the Guy, where after delivering the line "look upon my true form and despair!", his true for is revealed to actually be A Waddle Doo that goes down in one hit.
Played straight in the final battle against The Guy. After killing his (small, humanoid) form, you think you've won, only for him to crash through the wall in the form of a giant, laser-spewing, spike-laden, ill-tempered head.
In Dragon Age Origins, the boss mage Uldred at the top of the circle tower reveals his true form as a Pride Abomination.
In the Awakening expansion, the Baroness does the exact same thing.
Also, Flemeth turns into a dragon for her boss battle.
In the finale of Dragon Age II, no matter if you side with him or not, First Enchanter Orsino uses Blood Magic to transform himself into the Harvester from the Golem of Amgarrak DLC of Origins.
Virtually every human or humanoid boss in Breath of Fire III did this. Mikba, Balio and Sunder, the Professor, Teepo, Rei - hell, even the main character, Ryu. Just to hit the nail in further, when Balio and Sunder combined to form Stallion and when Mikba assumed his true form, they each said, "No one has seen us/me in this form and lived!" But considering this game's great love of random bosses, its not surprising that every boss trope in the book was visited a few times. The rest of the the BoF games are just as full of transforming bosses.
Taken to an extreme in Wild ARMs 3, in which the final boss has a whopping ten forms.
The first Wild ARMs game has a few of these. Several bosses will take another form after their apparent defeat, only to return bigger and badder than ever (so they claim) such as Mother, Ziekfried and Boomerang (after his final death you can fight his resurrected form in the arena). Alhazad doesn't transform, but he has always worn a white cloak covering his body, and he finally takes it off to reveal his true form. But the best example in this game that fits the trope perfectly is Zed - a bumbling wannabe boss who in a side quest late in the game finally loses his cool and turns into his true form, a huge grotesque monster and becomes arguably one of the toughest bosses in the game.
In Arc The Lad 2, every single human enemy will transform into some kind of monster or another before fighting the heroes.
In Paper Mario The Thousand Year Door, Grubba is already a monster, but a roughly-human-sized, comical one. Before you fight him, he turns into a much more menacing-looking giant creature.
The original Super Mario RPG featured Culex, a Bonus Boss that looked like something right out of a Final Fantasy game - a small, unimposing sprite in the game world that turns out to be...well, this◊. He's a tougher fight than the final boss, but the game makes up for it by playing some classic FF fight music during the battle.
Bowser in the original Paper Mario super-sizes, and gains some cool blue flames on his shell, before the final fight with him. Paper Mario The Thousand Year Door's final boss, the Shadow Queen, also had two forms, starting off as her form where she first possess Peach, then going into her noteriously hard true form. This is also used in Super Paper Mario when Dimentio possesses Luigi and turns into Super Dimentio.
In the original Ninja Gaiden series, the final villains (Jacquio, the Demon, some stupid scientist) all go through transformation sequences as Ryu defeats their forms successively.
In Ninja Gaiden for the Xbox and its Updated Rereleases, humanoid Fiend Alma turns into a scorpion-like thing once her power gets Awakened. After Doku sheds his corporeal shell, he loses his legs to float and gains a nodachi worthy of the One Winged Angel himself. The Vigoorian Emperor goes from a vaguely angelic statue to a bony creature made of skulls. Admittedly, the first two don't occur immediately after they get defeated the first time, but still...
Somewhat subverted because most everyone thinks that Alma's first form is harder.
Then, of course, there's Ganon/dorf from The Legend of Zelda. In Ocarina of Time, you fight his phantom incarnation on horseback, then him personally first as evil sorceror-king Ganondorf, after which he calls upon the Triforce of Power to transform into the shadowy boar-monster Ganon. A later game in the series reversed this by having you fight Ganon first, who then changed back into Ganondorf. Would this guy just pick a form already?!
In Majora's Mask, the final boss of the same name progresses from a mask with hair/tentacles (Majora's Mask) to a mask with arms and legs (Majora's Incarnation) to a giant, psychedelic, whips-for-arms demon (Majora's Wrath). It was also notable for allowing Link a supreme transformation into the Fierce Diety, only usable against bosses but still nigh impossible to lose with.
Subverted in Oracle Of Ages by game Big Bad Veran: Her true form is human, but she immediately transforms into something that looks like a "mutant fairy"... And her final "combat form" (which were actually three in one) is so ridiculous that she feels humiliated by having to resort to it.
General Onox of Oracle Of Seasons, on the other hand, plays it straight by revealing his true form to be a giant skeletal dragon.
In Twilight Princess, Ganondorf transforms early in the fight. The twist being that, this time, Link does it too.
This also applies to Vaati in The Minish Cap. At the beginning of the battle, he morphs from his human form into a taller, more powerful-looking version of himself, and after that's beaten, he changes completely into a giant, spherical beast with one huge eye and giant claws.
Bellum from Phantom Hourglass, however, is harder to classify. He starts out as a big, squid-like monster covered in eyeballs, then progresses to a possessed battleship. Once that's out of the way, though, he actually assumes a much smaller, humanoid form, via possessing Link's buddy Linebeck.
Malladus, the final boss of Spirit Tracks plays this straighter than Bellum did, but is still a bit odd, in that he attains his last, monstrous form by taking over Chancellor Cole's body, mutating it in the process. In a strange coincidence, the result ends up looking somewhat like Ganon's Dark Beast form from Twilight Princess, only more goat-like than pig-like.
Then Skyward Sword goes and inverts it, having the final boss Demon King Demise fought several times in a monstrous, demonic form before assuming his true, humanoid form for the final battle.
Oracle of Tao (No relation to the above two from Zelda) loves this trope. Not only does one of the middle game bosses do this, but the final boss of the game does it twice once during the normal conditions (two forms, unless you also count the one he abandons before the battle even starts), and again if you qualify for the Playable Epilogue (3 more). To say nothing of enemies that cheat the HP limit by having multiple attack patterns with the same form (one of those you have to kill nine times).
Or, as one youtube video puts it, he turns into the Oscar for Best Supporting Actor.
The "Devil Trigger" power of various Devil May Cry playable characters involves them turning into an uglier demonic form. This overlaps with Super Mode and Limit Break. More straightforwardly, bonus points to Credo for literally turning into a one-winged "angel".) Arkham of the third game goes from an already unpleasant humanoid demon form to an even worse blob form.
It isn't clear why, as even the heroes comment that he is still easy to defeat, being slow, weak and generally useless. Which is of course Cutscene Power to the Max for them and Cutscene Incompetence for him - there are good reasons why he is counted as a That One Boss (nevermind the grammatical issues).
His in game profile states that his blob form is a reflection of his inner evil.
Following Sonic Adventure, the Sonic the Hedgehog series seems to have grown to love this trope almost as much as Square Enix does. For instance:
The original Sonic Adventure has Chaos Zero, who actually has seven different transformations, one for each Chaos Emerald he absorbs.
Note that he never transforms into Chaos 3 or Chaos 5, as he was given two Emeralds at once as Chaos 2 and 4, respectively.
After absorbing all the Emeralds, he transforms from a water elemental-like mutated chao into a watery Leviathan powerful enough to destroy entire airships in one blast.
In Sonic Adventure 2, there’s the Biolizard, the prototype of the Ultimate Lifeform. After it was initially defeat by Shadow, its successor, it uses Chaos Control to warp right out of the room and binds itself to the Space Colony ARK
a giant space station housing, among other things, a weapon capable of destroying a planet
and begins a crash course for Earth.
Sonic Heroes has this happen to Metal Sonic who, after spending most of his time in the shadows, transforms into a titanic metal dragon called the Metal Madness, armed with the power of the aforementioned Chaos, as well as that of Team Sonic and Shadow. Three-quarters into the battle, he sprouts huge metal wings, further transforming into the Metal Overlord.
Following a botched attempt to mind control the main protagonist, Black Doom, the main Big Bad of Shadow the Hedgehog, transforms into Devil Doom, which was basically a giant two-headed dragon-like alien that melded itself into the Black Comet.
The handheld title Sonic Advance 3 has Gemerl. Following the initial final battle with him and Eggman, he swipes the Chaos Emeralds from Sonic, akin to Sonic The Hedgehog 3's intro cutscene, and uses them to transform into a berserk orb-like machine with laser-firing claws.
The main antagonist of Sonic and the Secret Rings, the Erazor Djinn, suffers a surprisingly unintentional version of this, turning into an ugly "incomplete monster" called Alf Layla wa-Layla after absorbing the World Rings following a botched sacrifice.
In Sonic and the Black Knight, there's Merlina, the Dark Queen. Throughout the course of the game, she goes from a harmless cute wizard to a scary evil sorceress to a giant armored knight with four arms, two of which are armed with building-sized swords.
Devan Shell transforms from a wimpy and nerdy turtle to a big winged turtle-demon at the end of Jazz Jackrabbit 2, appropos of nothing.
By beating the Adventure mode of Super Smash Bros. Melee on a hard enough setting, the last boss Bowser transforms into the giant beast that is Giga Bowser.
Brawl actually has this as Bowser's Final Smash, Gigabowser; Ganondorf gets a similar transformation, based off his Twilight Princess beast form. Mr. Game & Watch's Final Smash has him transform... into an octopus.
In the Subspace Emissary in Brawl, Tabuu, the Man Behind the Man (behind the other men), transforms into a winged version of himself that can transform the heroes back into trophies. But then Sonic comes and damages both of his wings, thus weaking his power to just an instant KO.
Although he doesn't refer to it as his "true form", Fox does.
Then there's Great Commander's second form from Star Fox/Starwing.
And the Phantron, which morphs into a jumping frog-like mecha for its second form, with a Scare Chord during the transformation.
Tales of Phantasia has Dhaos, who is first fought in his human form, then reveals his "True Power", a giant monster vaguely reminiscent of a giant armored purple-and-red Praying Mantis, then crosses the Bishonen Line by invoking his gods and turning into an angelic-like being -much like Yggdrasil from the later Tales of Symphonia. In the original SNES-version, he only has two forms; his human form and a black, mechanical-looking winged form.
As with most Tales tropes, this one applies to all of them. All the final bosses have at least two forms, usually with a spike in difficulty between the two (Yggy mentioned above would be the exception). Though Tales of Destiny's final boss deserves an honorable mention for being a cheap bastard, the most brutal is probably Tales of Vesperia: Duke gains a third form that's unlocked by collecting all the Devil's Arms and defeating his usual first two forms. The third form makes pretty much everything you've fought up to that point look like a joke, and if you've made the mistake of fulfilling the requirements to unlock it (which isn't hard), you must fight and defeat it if you want to finish the game. Thanks, Namdai!
The one game that doesn't fit in is Tales of Legendia. The final boss has only one form, though when you first fight her, the fight ends before you can deplete her HP, then there's a very long cutscene before the real fight, during which she is much stronger.
It doesn't apply to Tales Of The Abyss either, at least not as far as the Final Boss is concerned. The main villain has a second form but he stays human, just ditching his armor, letting his hair down and acting like an even BIGGER ham than usual. (Okay, so apparently one of his arms turns metallic and the other has feathers, or something, but he's still very recognizable as a human being, not a monster.)
All of the characters in the "Bloody Roar" series are capable of switching between normal human form and superpowered creature forms AND a glowing 'hyper' version of the beast form, but in "Bloody Roar: Primal Fury", the hyper-beast form of the true final boss, Uranus, is identical to her human form. Her beast form is a chimera, which is interpreted as blue and scaly with red lines, covered in spikes, and kind of bull-like, so yeah, it's a monster.
One character in Primal Fury's normal beast form...is a little, unimposing penguin. His hyper form is a seven foot tall phoenix-man perfectly capable of annihilating your world ten times over.
Not to mention that in her beast form as a bat Jenny looks extremely hot.
Subverted in the final battle of Mega Man 2; Dr Wily appears to morph into a green alien and the background changes to a starfield. After you defeat him, however, it turns out it was just a virtual reality machine.
Mega Man Zero is pretty fond of this as well. Not only the various final bosses transform at least once, also the four elemental masters transform.
While certainly not monstrous or one-winged, in X8 the True Final BossLumine not only triggers an angelic battlefield platform, but also grows six wing-like mechanical limbs from his back, now has bright red, slitted eyes, thin, long, and pointed fingers, and has a red crystal produting almost a foot out of his chest.
In Mass Effect, when you confront Saren for the last time in the ruined Citadel control room, he is initially in his (admittedly rather warped) normal form. However, after he is defeated or convinced to commit suicide (it depends on your dialog choices beforehand), the Reaper Sovereign uses its power to transform him into a large, spindly biomechanical monstrosity with exposed ribs and movements very similar to the earlier geth hopper enemy types, albeit far more dangerous. Whereas Saren's first form is a humanoid character not unlike your party members, his second is a highly mobile quadruped that vaguely resembles a metallic, skeletal lion. Only with the top half of his face still attached.
Arcanum's final boss, if engaged in combat, transforms into a massive bone snake-dragon..thing. Although in this case, he started out as a cloaked figure (so the transformation didn't really make him more 'morally OK' to kill) and the dragon isn't really very good at fighting, so I guess he just thought it looked cool.
He was supposed to be a lot tougher, but Troika accidentally flagged him as humanoid. Humanoids are hard-coded to deal no more than 10 points of damage in unarmed combat. Unofficial patch fixes it.
Kangaxx the demilich from Baldur's Gate II starts out as a moderately tough spellcaster, then transforms into a levitating skull that is immune to magic, immune to weapons of less than + 4 enchantment, regenerates, has an AoE instant death attack and casts some of the most powerful spells in the game, including 'Imprisonment', which not only causes instant irrecoverable death for the duration of the fight but can also break the plot.
You can recover people from Imprisonment with a Freedom spell. It's just that there are very few of these available.
There's also Abazigal in Baldur's Gate II: Throne of Bhaal, whom you fight first in human form, and then in dragon form. Ironically, the dragon form was easier to defeat than the human form.
Parodied with particular glee in Kingdom of Loathing, where the Naughty Sorceress reveals her supposedly true form. After you beat her in her hideous true form, she then assumes her actual true form: a sausage. Then again, she is an evil sausage brimming with dark magic. Your character then loudly proclaims, "How many times do I have to kill you? This battle has taken over a half an hour and there's no save point!" (Said sausage is a Clipped Wing Angel, as you jst have to have the Wand of Nagamar in your inventory to beat it.
Later in the history of the game, Ed the Undying was introduced, who had seven forms, each weaker than the last. Even people who hate the quest in which he's involved love his dialog.
Parodied with the Fallen Archfiends, a minor enemy in the Gate to Hey Deze. One of their "failed" attacks... well, a summary just wouldn't do it justice:
He glares at you and his arches glow a bright gold. "Now you will see my true... my true... ugh..." the fiend clutches his right arm, shouts "I'm comin', Elizabeth!" and falls down.
It's played oddly straight with their critical hit attack, though.
Played straight with the final, demon form of your Nemesis. As opposed to other examples of this trope, however, if you beat the first phase but lose to the demon phase, you can buff and heal yourself, change your equipment, even adventure elsewhere, and when you attempt the fight a second time you don't have to fight the first form again.
Dr. N. Brio in the first Crash Bandicoot game, who drinks his own Psycho Serum to mutate into the penultimate boss.
A lot of the bossess from the Crash Bandicoot games are mutated Australian animals, one being Koala Kong who is a mutated koala and very similar to the Hulk.
The Disc One Final Boss in Adventures of Rad Gravity, Agathos, is a human mutated into a giant living brain.
In Ys V, The Brute, Dorman and the Big BadSealed Evil in a Can, Jabir mutate into grotesque monsters for their boss battles; Dorman resembles Gadis's one-winged angel form from Dawn of Ys, while Jabir looks similar to Galvaran (he may be one of the Ash Emelas monsters).
Garland in Wanderers and Oath does this, as well as becoming Large and in Charge.
In Ys IV: The Dawn of Ys, the Big Bad Arem transforms into a gigantic humanoid blob, after you defeat his normal and Super Mode forms. Actually more of a Clipped Wing Angel.
In Ys VI, Ernst uses the power of the ark to become a "two-winged dark angel". After his defeat and subsequent return to normal form, he tries to draw more power from the Ark, but suffers a fatal Super Power Meltdown and causes Napishtim to go haywire.
Shining The Holy Ark: Panzer absorbs some of the evil from the Holy Ark to turn into a monstrous final boss - an interesting variation in that Panzer is actually The Dragon.
The Final Boss's first form in Monster Lair is a clone of the original Wonderboy riding a dragon, but for his second form he grotesquely morphs into a green "space ghoul" type monster. Horrifying, considering this is a rather "kiddish" game, although Nintendo Hard. However, this form is relatively easy compared to his first form and a few other bosses, thus it may be considered a Clipped Wing Angel.
The end boss of Legend of Dragoon had four different forms, each one symbolizing one of the seven days of the creation of the world. None of them actually looked like anything in particular.
Also counted as a Marathon Boss, since depending on the equipment could take upwards of 4 or more hours (it helps to have a magic regeneration ring and have the white dragon in play, but still...)
Giygas from Earthbound. At first, he looks like a giant eyeball with Ness's face on it, but this is just the result of using a machine to stabilize his form. After you damage Pokey enough, he turns off the machine and Giygas assumes his true form, which has to be seen to be believed.
The initial Giygas fits the bill as more alien like, seen in preceding game Mother as a more humanoid alien with vaguely lengthy appendages (who looks suspiciously almost exactly like Mewtwo), within a chamber attached to a huge machine. The previous information continues to apply.
Skies Of Arcadia First you fight Ramirez, then he sacrifices his life to control Zelos, the Silver Gigas, and then he crosses the Bishonen Line. Interesting in that the boss's original form is perfectly visible inside his translucent One-Winged Angel form.
All three of the major bosses in God Hand fall into this, since they generally appear humanoid but are actually extremely powerful demons. Fat, cigar-smoking, and inexplicably Mexican Elvis turns into a 20 ft tall gray giant with huge mouths for hands, another huge mouth and eyes on his stomach, and a very small featureless head., Succubus Shannon is actually Her own upper body with the lower body of a demonic cat thing and a giant eye on her face., and Bezel, who in human form looks like a guy in a suit with gray hair and skin and long pointed ears, but in demon form is First a worm with a fly-like upper body and blade-limbs, then a huge fly with blade limbs. Both forms have Bezel's face on their back.
The Tekken series has such boss characters as Ogre's transformed state True Ogre (which resembles Beast from Disney's Beauty And The Beast but with a snake for a left arm). In 'The Devil Within' subgame from Tekken 5 Ogre goes through even more transforming states. While you don't fight them always (never Jinpachi, sometimes Jin) in their normal forms prior to their transformed forms, Devil Jin and Jinpachi from Tekken 5 are transformed characters. They are for most characters the second last and final bosses. In both cases, they are infected with the Devil Gene, so if the Devil Gene is seen as the enemy, it is incarnating within two separate people. If Devil Jin defeats Jinpachi, he absorbs his power and transforms further, though he is not someone who can be played or fought.
The Mortal Kombat series has this in almost all of their later games including Zombie Liu King from Mortal Kombat Deception.
Mortal Kombat Mythologies: Sub Zero had Shinnok transform into a polygon demon once Sub-Zero takes the amulet, but fighting him in this form is optional, as a portal leading to the end of the game opens up anyway.
The boss of Monster Madness: Battle For Surburbia is Mr Huggles, a parody of Barney the dinosaur. At first, he attacks by singing and hugging. After you fight him his suit comes over revealing his hideous true form, a slimy Jabba The Hutt-like creature.
Primal has a main character who can turn into different monster forms.
The Shadow Hearts series does this a lot. In the first game, every human boss enemy transformed into a monster of some sort to fight you. Largely due to powers of Malice or a pact. Or both.
Interestingly enough, quite a few of the main characters can as well the list includes: Yuri, Kurando, Shaina and Johnny. The most literal version though is Yuri's Seraphic Radiance fusion.
In the Gungrave series, many bosses become like this due to the series' Psycho Serum / phlebotinum / green rock, the Seed drug. All of the "Big Four" bosses Grave fights usually morph to a mutated "overkill form" in the second round or as soon as he encounters them. Oddly enough, the final boss of the second game doesn't transform, he just gets some new attacks during the second phase of the fight.
MS Saga, the Gundam RPG, has this. The final boss starts off piloting the Alpha Azieru from Char's Counterattack. Defeat that, and he uses the G-System to reconfigure it into...a demonic-looking version of the Wing Zero Custom from Gundam Wing, complete with two pair of realistic black wings.
In Diablo, the Dark Wanderer character (Diablo in the Diablo 1 Warrior's body) slowly transforms into Diablo starting from the beginning, up until just before Act 3 is completed. Similarly, Baal, having taken over Tal Rasha's body in a similar way, slowly transforms him beginning with his release prior to the completion of Act 2, until the final form seen in the opening movie (and final battle) of the Lord of Destruction expansion pack. King Leoric, the Skeleton King, also underwent a similar transformation, though he was able to resist full possession by Diablo. The Warrior's use of the soulstone may have made him more vulnerable to this though. Prince Albrecht pretty much succumbed immediately though, similar to how Griswold instantly became a zombie.
King Leoric was able to resist because at the time Diablo had just reawakened in the Soulstone. Prince Albrecht could not resist because as an infant he had little if any willpower to resist. The Warrior fell relatively easy because most the deeds Diablo caused Tristan were perpetrated to strengthen Diablo as well as perpetuate a Xanatos Gambit to attract a hero powerful enough to kill him in Prince Albrecht's altered form and who would think that they were able to imprison Diablo in there mind, body and soul. Of course, Diablo by this time became powerful enough to gradually takeover the Warrior's body gaining a much more powerful host.
Joka from Klonoa: Door to Phantomile has the ability to change between his normal floating-jester-balloon form and a conspicuously monstrous form which resembles some sort of sea monster. This form is invincible, but can only be used during an eclipse; he can be forced to revert by stopping the magically-caused eclipses taking place during his boss fight.
In Klonoa Heroes: Legendary Star Medal, he has an entirely different second form: "Flower Joka", which is basically his normal self, except flower-shaped instead of spherical. Again, he shifts between this and his normal form during the fight, this time at will; luckily, his Flower Joka form can be damaged as normal.
Klonoa 2: Lunatea's Veil features a variation: Leorina, thought by the heroes to be the Big Bad, is forced to go One-Winged Angel by the real Big Bad, the King of Sorrow. She's not the Final Boss, either. Surprisingly, the King of Sorrow does not go One-Winged Angel during his boss fight, instead preferring to attack you from within a weird orb thing.
In the first instance, Agent Oranchov shoots some drums of Alien spores to mutate himself.
in the second instance, at the end of the game, Milenkov reveals his true form, a heavily-armored Blisk.
Resident Evilquite likes this trope. In the second game, WilliamBirkin initially appears as a somewhat mutated man and keeps reappearing in progressively less human forms until by the end, he has degenerated into a mass of teeth, flesh, and tentacles. Mr. X initially appears as a large man, but grows a pair of massive claws by the end of the game. In RE3, Nemesis first appears as a bazooka-wielding Mr. X-like humanoid, then sheds his Bad Ass Long Coat revealing his Combat Tentacles, then finally resembles a giant squid with legs. Later, in Code Veronica, Alexia appears as an ordinary human at first, but mutates into a hideous queen ant/human hybrid and then a dragonfly-winged thing by the end. In the Resident Evil 0 Dr. Marcus becomes a huge mass of leeches just before fighting the characters. Finally, in Resident Evil 4, Mendez, Salazar, and Saddler all have hideous final forms. To make things rather more disturbing, they all seem to be in complete control of their mutations, unlike bosses in the previous games.
Krauser goes "One-Clawed Angel".
Resident Evil 5 continues the tradition in grand style. An interesting example is where this is forced by the hero with Albert Wesker. Realizing that the Bishonen Line has made him Nigh Invulnerable, Chris injects him with The Virus, and he ends up having to mutate into a perfectly killable monster to fight it off (yes, even his biggest mistakewasn't his own fault).
An even earlier example RE 5 is Ricardo Irving, who injects a mutagen given to him by Excella and turns into a hideous sea-dwelling, multi-tentacled monster, complete with NarmtacularLampshade Hanging:
Parodied in BloodRayne. The final boss of Act 2 is General Mauler, a 10-foot tall Nazi cyborg with incredible durability. When you first empty his life bar, he collapses to the ground, then gets back up again, raises his arms high, triumphantly declares "You can't beat me that easily!'', then... promptly falls over dead.
Baten Kaitos has several examples. In the first game there's Geldoblame, Fadroh, and the final boss Malpercio (who started out as a giant monster to begin with). The second game has all of Malpercio's Afterlings. The oddest example would be one from the first game, in that after Kalas's Face Heel Turn, he grows a second wing, as he only had one wing to begin with and had to make due with a mechanical prosthetic for the other. So... he goes from being a One-Winged Hero to a Two-Winged Villain.
Fadroh transforms into a huge, vaguely jester-looking giant monster with a crotch-mounted eye. His main special attack consists of leaning back and firing Eye Beams from his pelvis.
Geldoblame tramsforms into a giant, deformed monstrosity. With Jiggle Physics. It will make you want to blind yourself. During the ending, he shows up once again, this time as a giant head sticking out of the ground.
Metroid Prime has the titular monster starting out as a huge armored monster, then becoming a squid-like creature.
Though there is some debate about which form is harder. First form's attacks hurt a lot more, but the 2nd one can only hurt with a the Phazon Beam.
In Metroid Fusion, the SA-X's form after being defeated in its Samus form is a freakish monster, then a Core-X.
Metroid Prime 2 had the Ing Emperor go through 2 very bizzare forms during the fight with it.
Kirby has faced a fair few of these. In Kirby Super Star there's Marx, and Kirby 64 has both Possessed King Dedede and the final form of Dark Matter, sorta. And there's even a regular enemy, Scarfy, that pulls this rather terrifyingly.
The recently released Kirby Super Star Ultra manages to one-up on Marx in "The TRUE Arena" — if you get to the final battle, you will see a movie where Marx brings back his soul by absorbing Nova's power. You will then fight Marx Soul, which is a more powerful and even freakier incarnation of Marx that has an absolutely terrifying death scream.
Several bosses in the Tomb Raider series: in II, Bartoli turns into a dragon, in III, Dr. Willard is mutated into a grotesque human/spider hybrid creature, and in Angel Of Darkness, Boaz is shoved into a pod of some sort and mutated into a giant slime-spitting cockroach-like creature (then turns into a skeletal Clipped Wing Angel). Honourary mention goes to Natla from the original game, who fixes herself up as a two-winged version for the final showdown.
In Silent Hill 2, Maria transforms into a gray-skinned tentacled levitating upside-down-in-a-cage abomination for the final battle.
In the original version of Lunar: Silver Star Story, the main villain would announce that it wasn't over after being defeated. He then turned into a rather stereotypical anime demon for no explicable reason. In the Silver Star Story Complete remake, this transformation was left out completely. Chalk it up to cliche overdose.
In both versions of Lunar: Eternal Blue, Zophar has multiple forms. When he finally appears on screen, he's this giantic Eldritch Abomination, but after he kiddnaps Lucia and takes Althena's power, that form turns into his fortress and what he turns into... saying he looks like a crossdresser would be an understatement. Despite how powerful the plot makes him out to be, the general opinion is that he is very easy, which even the game's characters seem to notice, but then he goes into his ultimate form, in which he is takes up a big chunk of the screen. In the original version, he still looks very femine, but in the remake the designers realized they freaked the player out enough and make him look more masculine. Both versions, you can't hurt him until Lucia frees herself. His first form was just a warmup really, his 2nd is going to a nightmare unless you've done a lot of level grinding. He has one more form after that, which you only fight with Hiro and Lucia. This form is, not supriousingly from the look of it (a chunk his his upper torso attached to his head in the original, and wierd disembodied beak in the remake) is a cakewalk even though you only have two characters (Zophar's 2nd form was meant to be the ultimate challange of the game, the 3rd one is practically a scripted fight).
Parodied hard in the Sega CD adaptation of Space Adventure Cobra. When a rather fragile sentient plant is confronted, it proceeds to laugh mockingly at Cobra before turning into a gigantic demon. Its speech is cut short at "My name is..." when Cobra blasts it, splattering it all over the room. Afterwards he notes "Next time I'll just whack it upside the head with a newspaper."
Revelations: Persona does this to its Big Bad, Guido, when you defeat him. The associated dialogue is just too ridiculous, funny and Macekred to not include:
Guido: This can't be! I'm a God! I'm invincible! (pauses) Something's invading my body!!
Massacre's voice: Hahaha! Stupid human, I shall give you the power you desire!
Guido: Stop!!!!!
Mary: What's happening?
Mark: What the heck!?
Nate: He was taken over by his own Persona!
Guido: Now I'm Super Guido!
From Persona 3, the Appraiser of Death first shows up in human form ( two of them, in fact.) When it is time to make a choice concerning the fate of the world, he claims that he will soon turn "into something unrecognizable" —sure enough, during the Dark Hour of the Promised Day, he becomes Nyx Avatar, the Shadow of the Death Arcana with four midnight-black wings and a grinning white mask.
In Persona 2: Innocent Sin Nyarlathotep first fights the party as Hitler, then transforms into a monstrosity that's way too hard considering he's just screwing with the party by that point. Later in Eternal Punishment he gets slightly more serious, fighting in his default form of the Moon Howler and once you beat on that enough...
Nyarlathotep: Fuhahahaha! This is! Splendid! You are the first to see this form! Die with my highest praise!(sic)
Of course he turns into a tentacle monster instead of an angel. Considering the Tabletop RPG above and that he was behind Guido's transformation before being Macekred out, it becomes obvious that the Crawling Chaos just can't stay away from this trope.
Persona 4loves this trope. The first time is just before the fight with Nametame, who is possessed by Kunino-sagiri and turns into him. Then, the real killer does it, transforming into Ameno-sagiri, God Of Fog. If you get the True Ending, Izanami does it twice, first becoming her Goddess form, and then turning into Izanami-no-Okami when you use the Orb of Sight. On top of that, everyone's Shadow (arguably) does this. There are eight major Shadows... so Persona 4 does this twelve times in total.
A minor, nonfantastic version of this occurs in Ace Attorney Investigations. A common theme in the series is for villains (especially the Big Bads) to take on totally different demeanors after you've exposed their true nature but before they're defeated, with one of the most dramatic being Matt Engarde in Justice for All. However, Quercus Alba practically changes into a different person when you expose him as leader of the smuggling ring. He stands up, throws away his shawl and cane, and goes from cowering to smirking. And then shit gets serious.
Mimi from Super Paper Mario is not the Big Bad (in fact, she turns good at the end), but she transforms into one of these frequently. It's also really disturbing. Oddly enough, you don't battle her regular girl form until the second time you battle her.
This is later played straight with the actualFinal Boss, Dimentio, when he merges with the Chaos Heart and Luigi, believe it or not to form a giant, harlequin monstrosity.
The final boss of La-Mulana is Mother, who takes five forms: a large stone face, a white flying silhouette, a disturbing Virgin Mary look-a-like complete with what resembles Baby Jesus in her arms, a pair of eyes, and finally, a smaller but no less deadlier version of her second form.
Subverted with great gusto in Dark Cloud 2: the true form of the terrible, Dark Emperor Griffon who has been erasing people and places out of existence is a cute anthropomorphic bunny (or "Moon Person" in the Dark Cloud world) no taller than Max. However, when he absorbs the power of the Sun, Moon, and Earth Atlamillia, he becomes a towering, muscular behemoth with enormous sapphire wings. During the battle with him, he can even rip off these wings to use as swords; as his power destabilizes, he grows even more muscular and his veins shine with the magic running through them. Defeat reverts him to his small, fluffy, and adorable lapin form.
The previous game in the series, Dark Cloud, played this one straight, more or less, but also pulled a bait and switch with it. The enormous, fat, oafish-looking Dark Genie, when destroyed, turns out to have been a mouse that got sealed in the urn with the Genie, and had absorbed some of its power. Then the REAL Dark Genie manifests itself as a tower of muscle with no lower body, arms that can punch up out of the floor, and killer magic beams. THEN, when you kill it in THIS form, it turns into its final form—a massive creature resembling Gospel from the Mega Man franchise.
Even a vertical shoot'em'up with space fighters can have this. In the final level of Tyrian Vykromod, the alien assassin who's been stalking the player for some time, seems to turn into a giant floating face - a pair of eyes, a nose and a mouth
Sort of a NarmBody Horror moment, played for fun. Vykromod certainly isn't pleased with the process, or the result.
World of Warcraft has several bosses that transform during battles; Illidan Stormrage shifts into and out of his fully demonic Metamorphosis form (as opposed to his normal half-night elf, half demon form); similarily Leotheras the Blind shifts between being a Blood Elf and a Demon (until eventually splititng into two separate forms); similarily several dragon bosses who start out in humanoid forms. Saidan Dathoran/Balnazaar and Baeren Westwind/Mal'ganis revert to their true demon forms mindway through battle, being previously disguised as humans.
Demonology Warlocks can learn the "Demon form" talent that transforms them into a demon for a short period, buffing their armour and spellcasting.
A few other bosses go through consecutive transformations throughout the fight. Thus, Eldritch Abomination C'thun starts out as a giant eye, before turning into a huge bloated body with a lot of teeth and eyes. Even more proeminent with Yogg'saron, whose first form is humanoid, and second form is... well... his title is "The Beast of a Thousand Maws" and it fits him to a T.
The Black Knight is a regular NPC you fight in a mounted duel after a short (but annoying) quest chain. Being an agent of the Lich King, he comes back zombified as the final boss of the Trials of the Champion instance, resurrecting the announcer who he force choked earlier as a ghoul. You kill him, but you can't loot him. Because he's back AGAIN, only this time, he's a skeleton. And then he summons about 10 ghouls. And then you kill him. And THEN he comes back as a ghost, even more powerful than the ten ghouls of the previous phase. Which you kill. He finally stays dead - until tomorrow, when you do the instance again!
In the Icecrown Citadel raid dungeon, we have Professor Putricide (who happens to be one massive Shout Out to Professor Farnsworth ). He imbibes some of his own concoctions during the fight, causing him to become extremely muscular and grow a pair of tentacles from his back a la Doctor Octopus. Disturbing...
Putricide is very much a parody of this trope. During his two transformations (it's a three-phase fight) he stuns the raid with "Tear Gas," runs to his lab bench, grabs a potion and declares "Hmm... I don't feel a thing. Whaaa?? Where'd those come from?" first, and "Tastes like... Cherry! Oh my! Excuse me!" the second time.
Also during the fight one of the raiders has to do this and become a Mutated Abomination and eat the ooze around the room that the Professor throws around and forms puddles.
The trash (ladies of the night) before the Maiden of Virtue (see the irony?) transform into their true form (sucubbus or undead) when they hit half health.
In the Dragon Soul, the final raid of Cataclysm, Deathwing undergoes a transformation between his first and second encounter. At the end of the first, he crashes into the Maelstrom, and at the start of the second emerges from it as a hideous monstrosity, complete with molten tentacles and appendages clinging to the platforms and attacking the players.
Similarly, in Warcraft III demon hunters like Illidan and mountain kings like Muradin can transform into bigger and monstrous version of themselves.
In Golden Sun, after defeating Saturos and Menardi, they transform into the two-headed Fusion Dragon.
The sequel has Agatio and Karst being turned into a pair of dragons, and the final boss is also a dragon made out of people, just not evil dudes going One-Winged Angel. And now Golden Sun Dark Dawn has the new villainous pair being absorbed into a dark beast thing while trying to power up the morphed Volechek
Nearly everyone that gets possessed by Rhapthorne in Dragon Quest VIII pulls some version of this.
Several overlords in Makai Kingdomstart in One-Winged Angel mode, instead crossing the Bishonen Line when they go all out... The exception to this amongst those with 'true' forms is the otherwise humanoid King Drake the Third, whose 'true' form is... Um... Unusual, to say the least.
In Soul Calibur 3 Nightmare pulls this off at the end of his story, an imput from the player turns him into Night Terror, a glow-y Nightmare with wings (and the true final fight of the game).
In Soul Calibur 4 Nightmare actually has a COMBO that transforms him into Night Terror.
Don't forget Zasalamel from 3. When he transforms into Abyss...yeah, good luck. Though he's nowhere near as hard as Night Terror.
City of Heroes has Romulus, who, after you beat him with only moderate difficulty in the third mission of his arc, merges with a Nictus in the fourth. His new self was one of the most challenging fights in the game at the time, and even now can wipe a unprepared team.
Panzer Dragoon Saga. In a single, long, psychedelic battle you first fight the five extreme forms of your own dragon, then Sestren - the final final boss, who of course changes into an even more horrible form.
ESP Galuda 2's 4th stage boss starts small, then becomes gradually bigger (by assimilating mechanical accessories) as he's nearing his defeat (as seen here). Normally, in shmup games, many non-final bosses feature minor weapons or parts that are (optionally or not) destroyed or discarded, as the boss start using increasingly more difficult attacks, and this example comes as an unexpected, uncommon inversion
In Blue Dragon, Big Bad Nene merges with a giant eternal engine to supply himself with infinite magic power for the climactic showdown. And let's not forget the REAL final boss, Destroy. When Deathroy (the little guy by Nene's side for the whole game) swallows Nene's soul, he reveals his true form as the monster that previously ended the world.
Nero Chaos in Tsukihime when he finally realizes that he is getting his ass kicked but refuses to run away eventually joins all the chaos left in his body into its ultimate destructive form, which isn't very well described except that it looks 'efficient.' The motion blurred picture given looks something like a worgen.
Dark Raven from Billy Hatcher and The Giant Egg} turns into a giant shadowy crow, with white eyes, and (eventually) covered in sparks after he hatches the titular Giant Egg.
Played straight for a few bosses in Batman: Arkham Asylum, but subverted for the final battle; Joker uses Titan to turn himself into a 15-foot tall hulking monster... then spends most of the fight mocking you from the sidelines while you fight waves of his Mooks, just like always.
To be fair to the guy, this wasn't his original plan: he actually wanted to force such a monstrous transformation upon Batman, then uses the drug on himself in an attempt to overcome Batman's Heroic Willpower to resist it.
Luminous Arc: the last boss turns into a beautiful white feathered serpent with lots of angel wings for its final form. The second game, Luminous Arc 2: does a similar thing as well except it resembles a fiery phoenix/giant plant.
You fight Balrog on four separate occasions; on the third, he's transformed against his will into a giant frog.
In the fight against the Doctor, he starts off looking like himself. Upon defeat, he loses control of theRed Crystal and transforms into a muscular berserker. After this, he dissolves into a red mist, which transforms Misery (whom you fought right before the Doctor) into a monster and forces her to fight as his flunky, and he possesses the Core (which you also fought earlier in the game). So the final round of the Doctor's fight is against One Winged Angel versions of three prior bosses. And Sue.
The True Final Boss starts off as a humanoid, then transforms into a giant, freakishly-smiling head. When you beat that, the head grows eight more eyes. When you beat that, his shell partially crumbles and you can see moaning faces within.
In Lego Indiana Jones 2, the end bosses of Raiders (Belloq), Crusade (Donovan), and part 2 of Crystul Skull (The Soviet Colonel) are all given a One-Winged Angel makeover, in forms that overlap with Rent-A-Zilla.
Alpha Prime has a strange case where the hero actually inflicts this upon the villain. The hero had previously heard that Glomar's heart reacts to the thoughts and personality of those who touch it, so he puts doubt into the villain's mind that it will not, in fact, give him power, but destroy him. When the villain touches the heart, it warps his body into a hideous abomination.
The Phantasy Star series has LOADS of these.
In the first game, the Saccubus turns out to be a projection of Dark Force.
Phantasy Star 4 has the Profound Darkness, which starts out monstrous, then gets more streamlined, and then turns into a naked lady a la 2's Mother Brain.
Phantasy Star Online has Vol Opt/Vol Opt Version 2, an insane computer with two forms; Dark Falz, which starts out as a strange three-legged THING, then turns into a floating spell-throwing machine, and then in the higher difficulties it turns into a much meaner floating thing with seriously unpleasant physical attacks and periodic invulnerability; and Olga Flow, who turns from an upside down six-legged warrior-thing into a two-legged warrior thing about the size of a large BUILDING.
C.A.R.D. Revolution has a double-barrelled final boss that turns from a girl with a sword-arm and monstrous chunks of mutated flesh that defines Body Horror into a thankfully less-messed-up creature vaguely reminiscent of a Delsaber.
Universe has a couple of versions of Magashi, and a double-barrelled Dark Falz with the added bonus of one of the coolest yet least feasible arenas of all time. Dark Falz reappears in Ambition of the Illuminus in a side mission.
Portable has Helga, Vivienne and Dark Falz AGAIN.
And finally Zero has Mother Trinity, who turns out to have been hosting Dark Falz.
"Mario and Luigi: Partners In Time" features one with Princess Shroob, who turns into a multi-tentacled beast. The fact that this is the SECOND Princess Shroob, and that you don't learn this until after you beat the first Princess Shroob, the existence of the second princess probably counts as an example.
Mario & Luigi: Bowser's Inside Story features the main antagonist, Fawful, transforming into Dark Fawful, and during Bowser's battle with Dark Bowser, the Mario Bros. fight Dark Fawful in a giant form with many limbs that must be attacked (similar to the previous two final bosses before him). Although in actuality he is really quite small, since Bowser can inhale him.
Dawn of War has a few of these: Chaos Champions and Heroes can function as the host of the Blood Thirster, a Greater Daemon of Khorne, the Necron Lord can transform into the Nightbringer or the Deceiver and an Eldar is sacrificed to bring about the Avatar of Khaine, though the latter isn't a game mechanic and the Avatar is produced like any other unit. It is shown in a cutscene though, They summon Khaine from a Dark Reaper aspect warrior, to fight against the Blood Ravens in the last mission against the Eldar
And there's the chaos sorcerer Sindri Myr who does this during the intro for the final mission, screaming "bear witness to my ascension" while tapping into the power of the Maledictum in order to become a daemon prince. It doesn't help though; the Blood Ravens still kill him
A rare case where the user is on your side occurs near the end of Dawn Of War 2: Retribution, where during the Eldar campaign a dying Howling Banshee offers herself to the heroes to awaken an Avatar.
Possibly spoofed in the game The Dark Spire where you encounter a "One Winged Angel" in a circus exhibit.
Celestia Lindwurm, final boss of the shmup eXceed 3rd: Jade Penetrate, transformed from a girl with wings into... a girl with larger bizarre-looking wings. Then Black Package came along, and she instead becomes a something like fifty-winged angel.
In most every Teenage Mutant Ninja Turtles game that came out after Secret of the Ooze, Shredder would turn into Super Shredder. In the SNES version Turtles in Time he would do this without you even fighting him as normal Shredder.
Ragna the Bloodedge from BlazBlue transforms into... some winged creature covered in shadow as part of his AstralHeat. Then reverts to his normal form for the winpose.
In Overlord 2 the final boss encounter is the Great Devourer. The Emperor, having gathered magic from across his kingdom, submerges himself in it and is transformed into a massive, glowing, zombie-spewing larva. Link.
Oogie in Oogie's Revenge turn into a giant monster after merging himself with mountons of bugs and trash.
In Body Harvest, the war with the aliens seems to be effectively over as Adam derails their last desperate plan and kills their leader, the colony Hive Mind. The Man In The Black Suit who's been menacing you throughout the entire course of the game then shows up and glibly informs you that upon the Hivemind's death he inherited all its powers, promptly transforming into the alien behemoth Tomegatherion, the True Final Boss.
Rise Of The Kasai features four bosses(two are fought at the same time) who transform before the battle even begins because...who can blame them? The heroes just infiltratied their impenatrable fortresses and slaughtered their mook armies. Three transform into dragons, and the final one transforms into a hideous spider like monster with the animated corpses of its mooks fused to its legs still lashing out at the heroes.
Mr. Big of N.A.R.C. fame is a fat man in a wheelchair who fires rockets while dozens of his henchmen dogpile you. After he is killed he comes back as a giant head on a floating platform whos flesh gets blown off to reveal a gaint metal skull.
Armon Ritter of Sin and Punishment 2: The Star Successor has based his entire fighting style based around this. He has three One-Winged Angel forms: The first is an enormous bat-looking things capable of summoning missiles, floating balls of goop that attack you at both long and close range, and fighter jets. His second is an giant insectile monster that can box you in and play a game of deadly pong in that energy box with you in it. And his final (and hardest) form? Five killer whales. Scareeee. At least all of his forms have a Godzilla/Mothra-esque scream that accompanies every charge shot you throw at him.
Later on, it turns out that every single one of the Nebulox has a One Winged Angel form, as well as you. This makes for one of the most entertaining levels in the game, along with one of the most challenging bosses.
The final boss of Super Adventure Island transforms into a freaky pig-elephant-gargoyle creature after becoming a normal angel as you kill its normal form.
The final boss of Adventure Island II is a larva that forms into a giant fly once destroyed. Yes.
Mem Aleph, the Normal and Law path final boss of Strange Journey, turns into a fetal being in a technicolor force field after you defeat her normal-looking form. This trick has been pulled in other games, notably Ōkami, but Mem Aleph's "empty" form makes up for it by being one of the hardest RPG bosses in existence.
It's not just her, either. The first four bosses come back in bigger, more powerful shapes in Fornax (their power is fully unhindered there); Morax evolves into Moloch, Mitra evolves into Mithras, Horkos evolves into Orcus, and Asura evolves into Asherah. Jimenez and Zelenin also enter their respective One-Winged Angel shapes as Awake and Soil Forms for Jimenez and Judge and Pillar Forms for Zelenin.
Digital Devil Saga's Hari-Hara has a reasonable first/first and a half form (it switches between them)...and then turns into a huge elemental core-creating thing.
In Shin Megami Tensei: Nocturne, Kagutsuchi starts off as...well, as one person described it, a giant disco ball. His second phase is a giant face...that spends the rest of the fight firing off a super-powerful almighty spell every other turn.
Not just Kagutsuchi. Chiaki, upon rejecting the last scraps of her humanity and becoming Baal Avatar, becomes a literal One-Winged Angel. The other Reason bosses might also count upon their respective ascensions.
Arcade classic Altered Beast was built around this trope. The player(s) fight their way across a scrolling platform landscape until they have collected enough power orbs to transform into their final beastman form (with special attack!). Then, when they next run into the member of the brotherhood of evil (a bald man in a coloured robe) that inhabits that stage, he says "Welcome to your doom!" and transforms into a huge (and usually surreal) boss monster.
The arcade game installment of the Cadillacs And Dinosaurs franchise: stage boss Morgan (a hunchback with a sub-machine gun) transforms into Morgue (a pachycephalosaurus knock-off) when defeated. Final boss Dr. Fessenden does this twice: first into a Morgue-alike, then into a two headed tyrannosaurus shivat with Fessenden growing out of its belly.
The eponymous final boss from arcade game Wardner takes a few licks in his evil wizard form, then transforms into a giant brown demon and starts spitting out a continuous maze of descending fireballs.
, starting from The Boss look-alike, a duo of flying rings, a walking mecha (and its head) and a disturbing pair of disturbing eyes.
Subverted in the Sam & Max episode "What's New Beelzebub?" with The Soda Poppers. Their "demon forms" are just different outfits, two of which differed only in color.
Played with in No More Heroes 2: Desperate Struggle with Jasper Batt Jr. Played fairly straight for his second form, for which he injects himself with steroids and dons a themed superhero costume (not unlike Batman's), before unleashing hell on you. Outright spoofed with his ridiculous third form, for which he somehow turns into a massive flying mascot-like baloon version of his former self - with a good dose of Clipped Wing Angel for this battle is MUCH easier than the second phase.
Dot Hack GU: Azure Kite reveals a form called the "Azure Flame God" after the player defeats him in the first volume. The true Tri-Edge, fought at the end of volume 2, also has a transformation of this kind. Finally, in volume 3, Sakaki also brings one out. Interestingly, most of the heroes in the games (including the protagonist) have One-Winged Angel forms alternately called "Avatars" or "Epitaphs", which they use to combat AIDA, as well as the various aforementioned transformations. These Epitaphs are... not the safest of powers to use.
The final boss of Odium, Vasili Dobrovsky, bursts into the room as a human, provides some exposition while announcing that he's the only man immune to the Viral Transformation that turned everybody into monsters, and when he's outed as The Dragon, he proceeds to turn into a giant monster anyway.
A variation, in that it's not exactly a transformation and does not instantly follow the first battle: one PC-98 Touhou Project game features an early boss that fights you using a flower-themed tank. She returns in the game's extra stage with a MUCH more intimidating Eldritch Abomination looking tank consisting of a humongous eye with bat wings, tentacles and an angelic halo. This form is widely considered as the hardest extra stage boss in the series.
In Perfect Chery Blossom, Yuyuko turns into a completely invincible shadow of her being in the last stage of the Final Battle. The music of this battle is appropriately named "Border of Life".
This happens to the T-1000, of all things, at the end of the SNES version of Terminator 2: Judgement Day. After a Ring Out Boss fight where you shoot it to knock it into the steel vat like in the movie, the T-1000 emerges from the vat as a giant man-shaped blob that spits molten steel at you.
The Scott Pilgrim Game parodies this in Gideon's first boss fight. His main mode of attacking is transforming into a statue of an actual One-Winged Angel.
Actually, the game plays the trope fairly straight as well. The first form of Gideon you face is Super Gideon, which is by itself a hulking, brutish form of him. Then he transforms into the aberration known as Gigadeon, which is a bona fide One-Winged Angel and references Kefka Palazzo's boss fight (see above). Subverted as the real final battle involves fighting a human-sized, robotic lookalike of Gideon wielding a pixelated katana.
In Rosenkreuzstilette, Graf Michael Sepperin assumes his demon form once he Turns Red. Also, in the final battle, Iris' One-Winged Angel form is that of her own humble self with three pairs of golden seraph wings.
In Jak II there's a twist at the end where Kor (spoiler filler) transforms into the Metal Head Leader, a house-sized monster that can fly and shoot lasers out of its mouth.
Deus Ex has Big Bad Bob Page with drastically enhanced nano-augmentations hooked up to a large ultimate augmented machine-thingy.
War, the third horseman in Apocalypse, grows to 50 feet tall in his second form.
In Albion, the Cuain, leader of the Kenget Kamulos, gets this as a perk with the job. He is able to turn into the avatar of Kamulos, the god of war. You fight the current Cuain, of course, and it's one of the very few real boss fights in the game.
In Adventure Quest Worlds, after being called pathetic for hiding in his teddy bear disguise by Lord Krom Wrath, Deady insults him for his lack of style sense and complies with his desire to see his true form before pulling off his teddy bear head and revealing his true form to be a giant tentacled skull with white eyes with light purple pupils in its eye sockets that goes by the name of Urkor Malravenus. Cue High Octane Nightmare Fuel.
Haunting Ground has Lorenzo who starts out at first as a creepy old man with paralyzed legs who can only crawl pathetically towards you. He then proceeds to turn into a much younger version of himself with seemingly superpowered punches. You defeat this version by pushing him into a pit of fire. He emerges from this in his final form: a flaming skeleton who can kill you inone hit.
GLaDOS from Portal, although it's more of inversion, with Forms of Morality, Anger, Curiosity and Cake being lost.
Bertrand from inFamous 2. As a powerful Conduit, he possesses the ability to transform into a gigantic half-insectoid half-reptilian beast called the Behemoth. Trouble is, it's pretty much his only ability besides transforming other Conduits into monsters, and it usually leaves him totally out of control until he returns to human form. As such, he's reluctant to transform into the Behemoth even in an emergency.
Inverted in the case of the Beast: he spends most of the game as a rampaging lava-skinned monster, laying waste to entire cities and showing no desire to communicate... up until the climax, when he transforms into a relatively ordinary-looking human to explain a few things to Cole.
In the Wii shooter Conduit2, John Adams (yes, THAT John Adams) infiltrates Atlantis, bringing several of his Trust soldiers in to fight you while he tries to snipe you from far away. After you damage him enough, you knock him back through a portal and end up in Agartha, the center of the Earth. There, Adams is no longer a chubby old man, but a giant, armored and horned alien. He laughs and comments on how it had been a while since he had been in his "true" form.
In the Wii version of A Boy and His Blob, the Emperor of Bloblonia begins as a single blobby mass on a giant throne who goes down in a single hit. [[spoiler: He then flees back to Where It All Began, and his form as the True Final Boss is an immense, be-tentacled writhing black beast that can only be defeated with the power of Mecha-Blob.
Tanzra in Actraiser starts out as a teleporting devil head, then turns into a much tougher skeleton demon.
Doctor Tongue in Zombies Ate My Neighbors quaffs his mad scientist potions and becomes, first, a giant spider, then a giant floating head of himself - that fires tongues!
The final boss in 'Readytorumbleround2' is a hulked-out version of Michael Buffer.
In Beatmania IIDX 19, STN (representing Wrath of the Seven Deadly Sins) starts off as a mech soldier. Once you defeat him and get the Demon Feathers from him, Levaslater and Rche, you unlock Neulakyussra, who represents the apocalypse. In its video, you see STN's armor crumble to reveal a white-haired man who then becomes a four-armed, three-headed being with the crests of the seven sins on each arm and head.
Darksiders has a heroic example. Main protagonist War begins the game as a gigantic flaming monstrosity, having been sent to play his part in The End of the World as We Know It. Getting Brought Down to Normal (or as close as a Horseman can get) is what tells him that something is not right. Later in the game he can return to his monster form at will once he gains enough Chaos and it serves as his Super Mode. In a Perspective Flip of this trope's usual applications some enemies have the power to shut off this form.
In the Tower Defense game Kingdom Rush, the Final Boss will turn into a huge firebreathing demon after he is "slain".
Hedge plays it normal, able to turn from a normal guy into a beastly hedgehog-man form, though he prefers to stay a hedgehog being most of the time and it counts as a Reveal when his human form turns out to be handsome.
Due to the incident that produced Ellen (long story), Elliot wound up permanently able to change into the cat-man form he'd asked Tedd to zap him into afterwards in order to chase her down. Unlike most examples, though, he didn't know he could do it until he involuntarily did it again to fight Hedge. Which knocked him out.
Except for her Omega form, which turns her into a feral squirrel with horns and razor claws. And she's ferocious as hell, as opposed to her normal bubbly self.
And Vlad does this in reverse. Ellen zaps him with a Gender Bender ray, turning Vlad the part bat, part bird, part Accidental Nightmare Fuel monster-man into Vladia, the relatively normal girl, the only change Vlad's likely to undergo due to a Painful Transformation problem that nearly killed him the last time he tried to be human: she's not sure she'll survive a gender shift, and doesn't want to risk it now that she's finally human.
Parodied much earlier in same with "Wing-B-Gone!" Which brings up a good point: wouldn't this be really inconvenient?
Lampshaded in Golden, when the villain sorcerer decides it is times to turn into his combat form to end the protagonists, and promptly turns into... a binturong with white spots. (And not a badger at all, whatever anyone is saying, no Sir.). The protagonists even comment on this:
Sorcerer: "Enough games! With all the powers of HELL at my command, I now take the form of the Ultimate Destroyer, a [...] fiend so diabolical, so terrible, that all who lay eyes upon his visage fall into..." (his bad guy monologue drones on the background)
"...yeah, he's going to turn into a dragon, isn't he?"
Wyler, a rich, weak mastermind from Art of Fighting 3, became one after drinking an elixir that more or less turned him into The Incredible Hulk.
One of Prof. Broadshoulders' (from Zebra Girl) defining characteristics is a "Mr. Yuk" face branded onto his forehead. Turns out It was actually a demonic third eye, and by opening it he turned himself into a demon.
Inverted in archcriminal Fructose Riboflavin's first appearnce in The Inexplicable Adventures of Bob!. He first appears disguised as a handsome, muscular human, and does all his ranty monologuing in that form. It's only after his scheme has failed that he drops the disguise as pointless, revealing his mildly creepy but not very frightening wizened old alien form.
In Problem Sleuth, Mobster Kingpin's imaginary self becomes Demonhead Mobster Kingpin for the final battle, which takes up nearly half the story.
Sluggy Freelance features a random mook getting infected with a "Cheesy Bossmonster Virus", which is pretty much this trope in a tube. [1]
In the "Holidays Wars" story, there's one on both sides: Bun-bun becoming a quasi-god of various holidays, complete with a different colour scheme, an occasionally visible aura of power, and an updated switchblade design and fighting Santa Claus who had become an alien monster some time ago and for this fight grown even bigger. (It doesn't really make sense in context, it's just Crazy Awesome.)
In The Angry Video Game Nerd's review of Super Mario Bros.. 3, during "Super Mecha Death Christ 2000 B.C. 4.0 Beta"'s battle with the possessed cartridge, it reveals its true, demonic form and the battle really begins.
In a later episode, the Nerd decapitates Bugs Bunny...only for him to reveal his true form...Woody Woodpecker.
In the flash series Madness Combat, Tricky the Clown morphs into a horrific monster of white flame for his final showdown with Hank in Madness Consternation.
In the GodzillaFan FilmGodzilla vs the Kaiju Killer, Stalkkus transforms into a dragonlike monster in order to fight Godzilla, who's been freed in order to kill him.
Subverted in Red Panda Adventures, "The Devil's Due": The villain attempts to hypnotize the Red Panda into thinking he's doing this, but it doesn't work and the Red Panda just laughs it off.
The Queen's "perfect disguise" in Snow White certainly counts, depending whom you ask; it's absolutely terrifying enough and—more importantly—it reflects the Queen's true nature.
And of course supremely ironic given that the Queen wants to be "Fairest of Them All".
In Sleeping Beauty Maleficent turns into a dragon to fight Prince Philip, respectively.
Maleficent: Now shall you deal with me, O Prince, and all the powers of Hell!
Disney parodied that scene as early as The Sword in the Stone, when Mad Madame Mim comes very close to ending her Wizard's Duel with Merlin by turning into a goofy-looking Dragon. Then Merlin wins by turning into an infectious disease.
In The Little Mermaid, when Ariel doesn't get Eric's kiss within the time limit, Ursula allows King Triton to trade himself for his youngest, and she takes his staff and uses it to turn into a giant version of herself. Then Eric crashes his ship into her, impaling her and also electrocuting her, oddly.
This seems brilliant only in the context of the rules set by the film; Aladdin basically used a Chekhov's Gun of a comment of the genie's back at the oasis. The actual djinni even in the proper translated Thousand And One Nights are enslaved in precisely one story: Aladdin, which features a 'slave of the ring' and a 'slave of the lamp.'
There was a mysterious slave from nowhere that dumped the transformed fish in the fire in 'The Fisherman and the Genie.' He may have been a genie himself, although the title character was just shut up in a jug so long he resolved to kill whoever let him out.
"You're crazy!" "No. Spiteful, vindictive, VERY large but never crazy."
Parodied in The Emperor's New Groove: Yzma is exposed to one of her own potions, and emerges laughing maniacally from a huge cloud of smoke only to be revealed as... a cute little kitten.
In an even more comical version, Kronk's New Groove features Yzma using a potion that will turn her into something that her enemies (in this case a bunch of old people who she sold fake potions to) cannot harm... a cute little bunny. Unfortunately for her, while they don't harm her, the local condor doesn't mind taking her for food.
In one episode of the Emperor's New School Yzma does turn into a giant snake. And in another episode she and Kuzco have a transformation potion duel—one of the things Yzma turns into is a Tyranosaurus Rex.
And she once made a potion that would turn her into the most hideous, terrifying thing imaginable, so frightening the other wouldn't be able to do anything about her... comically subverted when she transforms into herself.
Judge Doom in Who Framed Roger Rabbit is almost a sick parody of the "Look at my true form and despair" variation.
At the end of DuckTales the Movie: Treasure of the Lost Lamp, the villain Merlock uses his talisman to transform himself into a gryphon as an attempt to take away the titular magic lamp and use it to take over the world.
Drawn Together: When the King of Mexico drinks the worm . . .
In the Teen Titans: Trouble In TokyoOAV, the human bad guy leaps into a tank of magical ink, turning into a giant inky monster with metal tentacles, constantly spawning four-color minions.
A few characters on The Powerpuff Girls pulled this trick. In the episode "Knock It Off", for example, Professor Utonium's slacker roommate from college, Dick Hardly, gets some Chemical X and starts making hordes of Powerpuff clones, renting them out to big cities as a new crime-prevention system. When the Girls learn about his scheme and confront him, he tries to hide the remaining Chemical X by swallowing it... and turns into a giant monster.
Mojo became one giant ape in the Powerpuff Girls movie. Him also did this in the episode Speed Demon and Power Noia, though into two different forms. It actually works very well for HIM in Speed Demon and for Mojo in The Movie. So does Sedusa when she tricks the Gangrene Gang into stealing three egyptian artifacts for her. Not only does it restore her hair, it turns her into a giant, real-snake haired monster bent on destroying the Powerpuffs and Townsville. Remember, it's always about the tiara!
On the Osmosis Jones series, a corrupt mayoral candidate who has been illegally using growth hormones to sabotage his rival's campaign gets caught red-handed with the stuff, downs it in a panic, and you can guess the rest.
Kevin 11 from Ben 10 is an odd spin on this: His true form is his first form, an orphaned eleven-year-old boy with the power to absorb energy. Attempting to absorb the Omnitrix's energy, however, resulted in him losing the only thing he had left... His humanity.
Then again, there's more than one way to look at the phrase "true form":
Kevin: It's payback time for turning me into a freak!
Ben: You always were a freak, Kev. It's just that now the ugly's also on the outside.
Fortunately for Kevin, Ben 10 Alien Force ends with the Omnitrix destroyed (which Ben replaces with the Ultimatrix) and Kevin regaining his humanity as a result.
Doctor Victor, from the third season finale, is another straight example, an absurdly large NASA scientist at first appearance but secretly a hulking Frankenstein's Monster-esque alien beneath the facade.
The third season finale of Ben 10 Alien Force sees it happening a few times, with Albedo's Ultimatrix being able to unleash the "ultimate evolution" of the various alien forms. Ultimate Humongasaur is green and much stronger than the normal version, while Ultimate Swampfire is a tree with blue growths. And then once Vilgax's ship floods he unveils "his true form" - a giant squid/octopus.
Parodied with typical relish in a Halloween episode of South Park. The spirit of Wall-Mart revealed his "terrifying true form"... by removing his stick-on moustache.
Korn (stay with us here) tried to do a heroic version of this during their guest appearance in another Halloween episode. It didn't quite work out. "Korn powers activate! Form of - CORN!!!"
And in "Pandemic Part 2", there was an evil United States head of Homeland Security who, after revealing he was the leader of the guinea creatures, transformed into a GUINEA PIRATE.
Appropriately for a film that (ahem) was an intentional homage to the classic films, the villain in The Swan Princess has the ability to become "The Great Animal". His monstrous true form was teased throughout the entire movie until the very end - only to have him bring the Narm and change into what appears to be a big fruitbat.
Don Bluth likes Disney movies as well and has used this at least twice:
In the already insane Rock-A-Doodle, the Grand Duke appears to puke his evil magic up all over himself and mutates into a sort of gigantic owlish... tornado-ish... thing...
In Anastasia, which is also pretty damn weird when you stop and think of it, Rasputin's evil spirit seems to be building up to a spectacular One-Winged Angel act but the worst he does is scare people by dismembering himself. And then he sends an animated statue of Pegasus to do the big honking monster act. The hell?
The spin-off movie Bartok the Magnificent has Ludmilla (voiced by Catherine O'Hara of SCTV) steal a potion that Babayaga has given Bartok to aid him in his quest - it turns you into whatever you are, deep down inside. She drinks it and...
Don Bluth actually worked for Disney around the time of movies like The Rescuers, so he was just carrying on the tradition.
Hexxus, the spirit of destruction in FernGully, has three different monstrous forms. He starts out as a wad of toxic waste, turns into a cloud of poisonous gas, and finally appears as a NightmareFueleriffic burnt-looking skeleton covered in a cloak of pestilence.
Characters, particularly Batman Villains, in the DCAU like this trope a lot as well:
The Joker loved disguising himself and then revealing his true Monster Clown face (he's better known for doing this in The Movie);
Clayface... it's easier to say he really liked to turn into horrifying things during combat;
One of the more way-out examples is the episode "Home and Garden", where Poison Ivy created a race of plant people who start out as normal-looking babies (save for the fact that they've emerged from giant seed pods) but may suddenly mutate into huge, green, ogrish thugs;
Eventually it got to the point where the Preserver assumed a monstrous form to fight Lobo in the Superman: The Animated Series episode "The Main Man".
It was even nastily subverted by the time the Batman Beyond episode "Splicers" came along. The evil scientist leader of the Splicers pumps himself full of LEGO Genetics Juice, transforming into a fearsome monster combining the features of many creatures. Terry fights him normally for a bit, then gets the bright idea to inject more of the serum into the baddie, horribly mutating him into a blobby thing... that is actually still quite capable of fighting and, worse yet, is even more powerful than before.
Speaking of Batman Beyond, the writers liked this trope enough to play it fairly straight in just about every other episode. The episode "Curse Of The Cobra" is a good example; as a matter of fact it used LEGO Genetics as well.
This is also the series where the writers admitted they would blow up the building if they couldn't figure out a good way to end an episode.
In the terrible trio episode of The Batman, The Trio uses skin patches to administer the Langstrom serum. In the end Fox (a guy turned anthro fox) ends up turning into a griffin-like monster.
In Biker Mice From Mars, Fred The Mutant, Karbunkle's sidekick/assistant, is mixed up of different parts and absolutely loves pain. Another episode had a villain called Evil Eye Weevil, a skeleton like thing who is a No Celebrities Were Harmed parody of Elvis and Evel Knievel. Evil Eye Weevil could shoot a "hostility beam" at anyone and anyone hit by it would start fighting like crazy. Then again, the Plutarkians were never the picture of beauty either.
In the 2006 revival, Stoker (the Biker Mice's mentor) turns into an insane rat-like monstrosity called "Stoker Rat" by the light of the sun due to radiation.
Parodied in an episode of Catscratch. While the brothers are watching a scary monster movie, they are interrupted by Human Kimberly at their door with a gift of broccoli. Gordon is fiercely allergic to the broccoli and he puffs up so bad that he looks just like the monster in the movie. Mr. Blik and Waffle think he is the monster from the movie and run for their lives. When they can no longer run they are faced with their only option: fight the beast.
It also subverted in the episode with the Banshee. The true form of the Banshee is revealed to be a "beautiful" seal woman - depicted as a seal with a dress and long blonde hair.
Happens a lot in Jackie Chan Adventures. This happens to anyone who wears one of the oni masks, and in the final season it happens to the villain Drago, or anyone else, who absorbs a demon power. When Drago gets all the demon powers, the end result is quite...monsterous. Most people would probably say that Ultimate Power is not worth the price of looking so ugly.
In all versions of Spawn, Violator eventually changes from his Monster Clown appearance into a huge horned monster whenever he wanted to smack some stupid out of Spawn.
Spoofed in Igor where Jackyln runs out of pills and turns into her true form- a cute little Igorrette.
The Fairly OddParents has The Lead Eliminator, who eventually morphs into the powerful Destructinator in the "Wishology" trilogy.
Captain Simian And The Space Monkeys has "Gormungus", an alter-ego of Gentle Giant Gor. For roughly the first third of the series, pushing Gor's Berserk Button sends him into an Unstoppable Rage. After the malevolent alien Apax captures Gor and decides that the temper and strength make him the perfect gladiator, but that gentle side just has to go, he zaps Gor with a home-made mutagenic raygun. As a result, whenever Gor gets angry, he grows into a massive, more feral-looking gorilla creature, sort of a cross between The Incredible Hulk and King Kong, until he gets calmed down.
Aa'une went from glowing Evil Overlord to a giant monster with several tentacles when exposed to the energies of Lake Blakeer. Then in the next episode he goes down right Eldritch Abomination by growing extra mouths and even more tentacles.
Promptly subverted when Iparu's shapeshifting power allows him to assume an identical form and match Aa'une blow-for-blow in his powered-up state.
Phineas And Ferb makes a joke about this trope in the episode "Nerds of a Feather". A TV producer Dr. Doofenshmirtz has captured to pitch a TV idea to, who is voiced by Seth MacFarlane, says that when the holographic monster that Phineas and Ferb have made comes out that "having monsters come out of no where at the end of stories is lazy story writing."
Adventure Time:If you dare press Marceline the Vampire Queen's Berserk Button she turns into a giant, rampaging bat.
Koizilla is 'heroic,' but it also appears to have sunk most of the Fire Nation fleet, plunging thousands of naval personnel into the polar waters. Even assuming some vessels survived and were able to perform rescues and that the Water Tribe took a bunch of hostages for ransom, that still leaves the biggest kill count of the series on the Technical Pacifist hero. The season two finale, on the other hand, featured a villain winning the biggest city in the world: with zero casualties.
Said villainess then went to suggest preforming genocide on the entire Earth kingdom, meaning that she was only saving those people to kill them letter. Also Koizilla didn't appear to kill anyone (Zhao doesn’t count, that happened only after the spirit left Aang), seeing that if he did went on a rampage, not a single soldier would have managed to escape to the ships, yet many, if not all the Fire Nation ships managed to flee with Koizilla just looking at them from afar. Of course, if you want to get picky, there's the fact that all those soldiers that weren't killed would go on to further attack Aang and the earth kingdom again in the future, so there's really no moral choice here.
Interestingly, Hei Bai's One-Winged Angel form is the one we first see him in. He has a normal form, it's just that the heroes arrive in the middle of his Freak Out.
Galvatron from the Transformers series, an upgraded form of the series Big Bad, Megatron.
In the Foster's Home for Imaginary FriendsMovieDestination Imagination, Mr. Herriman makes the mistake of verbally threatening an emotionally unstable Reality Warper named World with the thing he fears most, to be sealed away alone again. World replies by destorying his imaginary world and transforming into a massive chimera creature to try and reclaim Frankie, the only person in years who has treated him with kindness. It actually works out pretty well for him as no one can really stop him until Frankie calms the poor kid down.
There is also Atomic Betty villain Maximus IQ becoming a giant demonic cat when he wore the Amulet of Shangra-La-Di-Dah in its titled episode.
