NAME: Hugh Jackman
CHARACTER: Logan, a.k.a. Wolverine
WHERE YOU'VE SEEN HIM BEFORE: The first three X-Men films; PEOPLE's Sexiest Man Alive 2008
PEOPLE's reigning Sexiest Man beefs up for every X-Men role, but this time he took his training even further. The Aussie heartthrob started working out a year before shooting began and stuck to a high-protein diet. "I work out imagining I'm Wolverine," Jackman told Access Hollywood. "Wolverine to me is the guy that when everybody else quits, that's where he begins." The result: lots of bare-chested sceen time showcasing his rippling muscles and a naked scene that reveals (almost) all. His prep work was so successful, says Reynolds, that Jackman, 40, "looked a lot like a guy who was going to make a necklace out of my teeth."
NAME: Liev Schreiber
CHARACTER: Victor Creed, a.k.a. Sabretooth
WHERE YOU'VE SEEN HIM BEFORE: Scream 1-3; CBS's CSI
NEXT UP: Currently filming Salt with Angelina Jolie
The bloodthirsty brother of Jackman's Wolverine, Schreiber's husky-voiced Sabretooth moves like a cat despite his hulking frame. How'd he bulk up for the role of a mutant with super-healing powers, razor-sharp claws and animal-like senses? "Fans [online] said, 'you need to get bigger,'" says Schreiber, 41, who has two sons with actress Naomi Watts. "I did the high protein diet; between [me and Jackman] I think we wiped out an entire gene pool of chickens."
NAME: Ryan Reynolds
CHARACTER: Wade Wilson, a.k.a. Deadpool
WHERE YOU'VE SEEN HIM BEFORE: 2008's Definitely, Maybe; TV's Two Guys, a Girl and a Pizza Place
NEXT UP: The Proposal with Sandra Bullock
Not content to be your garden-variety superhero, Reynolds shows off his guns in sleeveless T-shirts while infusing the character with his usual brand of cheeky, poker-faced humor. Deadpool, he says, is "a cross between Commando and Phantom of the Opera by way of Caddyshack." (Huh?) Reynolds trained for countless hours with katana swords to get ready for the role, and no doubt to wife Scarlett Johansson's great relief, escaped some close calls to very personal areas. "You're gonna wanna wear pants for that," Reynolds, 32, deadpans. "I honestly just about lost my 'future legacy' a couple of times."
CHARACTER: John Wraith
WHERE YOU'VE SEEN HIM BEFORE: Grooving with his Black Eyed Peas bandmates
Hip-hop star Will.i.am makes no bones about it – going from musician to mutant was a challenge. On the plane to Australia to begin filming, he suddenly realized he was on his own. "I tour with my friends, [and] here I am going for the first time to do the total opposite of what I normally do," he says. But taking on powers of teleportation and joining Team X with the other mutants was great fun for Will.i.am, 34, who told MTV News of Wraith: "He's just a badass who'll whoop [you]."
NAME: Taylor Kitsch
CHARACTER: Remy LeBeau, a.k.a. Gambit
WHERE YOU'VE SEEN HIM BEFORE: NBC's Friday Night Lights
UP NEXT: He's filming The Bang Bang Club with Ryan Phillippe
The Canadian hunk, 28, plays a mutant with attitude in the film. But, he says, he had to fake it – for a while, anyway. "When I first got there [I was] nervous," Kitsch says. "And when I ... met [Jackman], it was really great." To get psyched up to play a New Orleans thief with a gift for killer card-throwing, Kitsch turned on his iPod and listened to the bluesy John Lee Hooker "all the time," he says.
NAME: Daniel Henney
CHARACTER: David North, a.k.a. Agent Zero
WHERE YOU'VE SEEN HIM BEFORE: He's a major movie star in Korea; Wolverine is his U.S. breakthrough role
A former model, Michigan native Henney has been nurturing his acting career in Seoul, Korea, for the past few years, where his brooding good looks have given female fans heart palpitations and made him a household name. As lethal marksman Agent Zero, Henney, 29, is ice-cold – and plenty hot – in his relentless pursuit of Wolverine.
NBC; AdMedia; Wireimage