Some actors shed or gained massive weight. Christian Bale lost 62 pounds for The Machinist, while Renee Zellweger gained 30 for Bridget Jones's Diary.
Makeup magic helped actors disappear into their roles. Jim Carrey spent hours in prosthetics for The Grinch, and Charlize Theron transformed for Monster.
Shaving heads, bleaching, or drastic cuts—Anne Hathaway chopped her hair for Les Misérables, and Natalie Portman shaved hers for V for Vendetta.
Actors bulk up to look the part. Chris Hemsworth packed on muscle for Thor, and Hugh Jackman trained relentlessly to be Wolverine in X-Men.
Actors have played much older or younger versions of themselves. Brad Pitt aged backward in The Curious Case of Benjamin Button, thanks to CGI and makeup.
Zoe Saldana turned into Gamora in Guardians of the Galaxy, and Doug Jones spent hours in costume to become The Pale Man in Pan’s Labyrinth.
Some actors altered their teeth for realism. Rami Malek wore fake teeth to play Freddie Mercury in Bohemian Rhapsody, and Johnny Depp donned gold caps for Pirates of the Caribbean.