Transformation

Some of these fictional heroes transform themselves into their true identities or new bodies.

Animated films

 * The Beast transforms back into his old handsome human prince form, Prince Adam.
 * The Blue Fairy turns Pinocchio into a real boy.
 * Queen Elsa becomes a beautiful Snow Queen.
 * Wallace is turned into a were-rabbit in the light of the Full Moon.

Anime and manga

 * A-ko Magami magically transforms her different outfit into her most powerful sailor-suited battle uniform.
 * Serena Tsukino becomes Sailor Moon with the Transformation Brooch.
 * Sakura Kinomoto magically transforms into Cardcaptor Sakura. Sakura's different outfit also magically transforms into her school uniform, while she's transforming.
 * Goku transforms into a Super Saiyan after witnessing the death of his best friend, Krillin.
 * Baby Dragon becomes Thousand Dragon with Time Wizard's effect to age the opponents' monsters.

Cartoons

 * Twilight Sparkle transforms herself into an Alicorn princess.
 * Sunset Shimmer becomes Daydream Shimmer to defeat Midnight Sparkle.
 * Marinette Dupain-Cheng transforms into Ladybug with the Ladybug Miraculous.
 * Adrien Agreste transforms into Cat Noir with the Cat Miraculous.
 * Alya Césaire transforms into Rena Rouge with the Fox Miraculous.
 * Yumi Yoshimura and Ami Onuki transform their regular outfits into their battle outfits.
 * Daniel "Danny" Fenton transforms into Danny Phantom.
 * Ben Tennyson transforms into various alien forms with the Omnitrix.
 * Hot Rod becomes Rodimus Prime, the new Autobot leader.
 * Martin Morning involuntarily transforms into a new form nearly every time he wakes up in the morning.
 * BoBoiBoy transforms into various elemental forms with his power band.

Comics

 * Prince Adam transform into He-Man by Power Sword.
 * Clark Kent becomes Superman.
 * Bruce Banner becomes The Incredible Hulk when he gets angry.

Live-action films

 * Alex Murphy becomes RoboCop after he was brutally gunned down by Clarence Boddicker and his gang.

Live-action TV
The Winchester brothers, Dean and Sam, and their friend Castiel get turned into animated versions of themselves in the episode "Scooby Natural".

Video games

 * Link becomes the Fierce Deity Link with the Fierce Deity Mask to destroy Majora and save Termina from the angry moon.
 * Young Link becomes the Fierce Deity in the Hyrule Warriors series.
 * Mr. Game and Watch becomes an octopus to hit enemies with his tentacles.