LOS ANGELES — Whether critics walked out of "Indiana Jones and the Kingdom of the Crystal Skull" loving or hating it, most had something to say about Shia LaBeouf's dramatic entrance.

The 21-year-old actor plays Harrison Ford's sidekick in this fourth installment in the Indy franchise, and when he first appears on screen, he's a dead ringer for Marlon Brando's young punk in 1953's "The Wild One."

We're not talking a kinda-sorta resemblance. He's got the same off-kilter cap, same black leather jacket and he rides up on a motorcycle, full of 'tude. Brando played the leader of a biker gang that terrorized a small town back then. But LaBeouf? As young Mutt Williams, he's still a rebel in search of a cause in Steven Spielberg's latest blockbuster, set in 1957. And to his credit, the actor knows it.

"Steven wrote a little note on my script that said, 'OK, now it's time to transform yourself into Mutt! Signed, Steven,' and then he gave me three movies to watch," LaBeouf says in the film's production notes. They were: "Blackboard Jungle," "Rebel Without a Cause" and — wouldn't you know it? — "The Wild One."

"As though I was supposed to go home and watch 'The Wild One' and go, 'Oh, yeah, I see how Marlon Brando did it!' " he adds.

Fans of the former child star, who won a Daytime Emmy in 2003 for the Disney Channel series "Even Stevens," may have a hard time accepting him as a tough guy. But as LaBeouf said last year in an interview with The Associated Press — when rumors of his casting in "Indiana Jones" were swirling but still unconfirmed — this is a transition he's been planning for a long time.

"I want to get bigger. I'm sick of being a boy," LaBeouf said then of his workout regimen while promoting the teen thriller "Disturbia."

"I know that there's this innocence that I have, but I feel like I've played that guy. The whole goal for me has been diversity and diversifying your portfolio and making sure you do a whole bunch of different things and you don't get typecast. If I become a type, my career is over.

"I want to be an intimidating presence. I want to be a ... killer."