George Clooney, Chris Pratt and More Stars Who Have Pulled Hilarious On Set Pranks

George Clooney messed with Brad Pitt's Toyota Prius while they were shooting Ocean's Eleven.

“I got a bumper sticker in the shape of a pot plant, that said, ‘F— cops,’ and I put that on the back of his car,” he said. “Because there’s no way you’re not getting arrested with that.”

Chris Pratt completely shocked Amy Poehler by actually going nude for one of their scenes in Parks and Recreation.

"So I show up in these skin-colored briefs, and it's at the end of the day, I'm not quite eliciting the response that I was hoping to from Amy," Chris has said. "I was like three or four takes in. And to Mitch, our boom operator, I was like, 'Mitch, I'm gonna go snake out on this one. I'm gonna go naked.' And he's like 'Oh gosh, I don't know.' I was like, 'Too late!'"

While Amy's recreation was actually used in the episode, Chris ended up getting a letter from NBC reprimanding him for the prank.

While they were shooting The Monuments Men, George Clooney made Matt Damon think he was gaining weight.

"He took in my wardrobe by an eighth of an inch, every other day," Matt has said. "[He] had the wardrobe department do that because he knew that I was trying to lose weight."

"This was a job where I would go back to New York, where I was living with my family, and I would come back [to film in Europe] for two weeks. And then I'd go back to New York, and every time I came back my pants were tighter, and I was like, 'Ugh, this is weird. I've been going to the gym!'"

During one of her nude scenes with Kevin Spacey on House of Cards, Kate Mara wore nipple pasties with his face on them.

"I tried to get him to laugh by wearing pasties with his face on them," she said. "Of course, because Kevin wants to win whatever the game is and because he always wins, he did not laugh. He waited until the director said 'Cut' and then he laughed. Kevin has an amazing sense of humor, but he’s also a great professional and he’s really f—ing good at it."

While filming the Hunger Games Josh Hutcherson put a dummy in the bathroom of Jennifer Lawrence's trailer.

"They had a full life-sized dummy of one of our tributes that had gotten killed by a Tracker Jacker, and basically it's all swollen and gnarly-looking and mangled, and Jennifer was out of her trailer so I took the dummy and put it inside her bathroom in her trailer," Josh has said.

"I've been told that she actually peed her pants in reaction to it."

While filming Catching Fire Josh Hutcherson bought and sprayed something called “skunk poop” on a piece of toilet paper and put it in a garbage bin in Sam Claflin's trailer.

"I couldn't work out where the smell was coming from," Sam said. "I was going nuts going, ‘Oh my God, who’s gone into my trailer and had a s—? Seriously! It stinks!’”

While filming their sex scene for Paranoia Amber Heard surprised Liam Hemsworth with a dildo.

"I get into the bed and they say 'action, and then I turn over and I grab what I thought was her arm, and it was a giant dildo," he has said. "And I pulled it out, and everyone was in on it…except me, yeah."

While filming Maleficent, Sharlto Copley tried to prank Angelina Jolie by getting into an impromptu fight with her character's raven during a scene – however, Angelina had the last laugh.

"I came to the set at 6AM the next morning, I'm tired and I can't wait to get into my trailer. I open the trailer door and there are two huge ravens, real ravens, in the trailer!" he said. "One had s— on my couch and they're really intimidating birds. I did not go into my trailer [after that], it took 20 minutes to find an animal wrangler. It was this constant thing because she could make stuff happen, she had more resources than anybody!"