Brad Pulls 'Wham!' Pranks on Jonah

Brad Pulls 'Wham!' Pranks on Jonah

There's no crying in baseball! Moneyball star Jonah Hill tells ET that working with Brad Pitt on their Oakland A's behind-the-scenes drama was intimidating at first, but the A-lister quickly made the experience "cool" and enjoyable -- and pulled some pretty entertaining pranks on him to lighten the mood.

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"He's a maestro of pranking," says Jonah with an air of reverence. "He has a fortress of pranking genius around him. … He knows your moves while you're thinking of it. Prank chess, he's playing all the time."

Jonah reports that Brad decided on a Wham! theme for a few of his pranks, which gathered steam and then got pretty relentless, culminating in wrapping Jonah's on-set golf cart in pink and rigging it to blast Wake Me Up Before You Go-Go whenever he would turn on the "Wham! Mobile."

"He's really funny, he's really fun, and I think our relationship in the movie's kind of a big brother-little brother relationship, and I think we had that kind of fun energy with each other off set," says Jonah.

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In addition to stretching as an actor, the star of such films as Superbad and Get Me to the Greek is sporting a slimmer, trimmer frame, and Jonah chalks it up to priorities.

"Once something becomes a priority, at least for me, it just is a priority," he explains. "I went to a nutritionist and I just started running and doing push-ups and sit-ups and stuff like that. It's definitely a tough thing to do. Once you make that decision, you've got to stick to it."