7.George Clooney walked up to Ryan Gosling on the set of Ides of March to discuss something serious, but when Clooney walked away, Gosling realized that Clooney had actually just sprayed the crotch of his pants with water.
8.While shooting a scene for We're the Millers where the cast was supposed to sing along to TLC's "Waterfalls", Jason Sudekis had the crew rig "I'll Be There For You" (the theme song for Friends) instead to prank Jennifer Aniston.
9.Jonah Hill tricked Leonardo Dicaprio into eating a ton of sushi while filming a scene in The Wolf of Wall Street. Hill said, “I was supposed to say ‘yes’ and then eat it. But then I said, ‘No, buddy, it’s all yours,’ and then he had to eat it. So he had to match that take for the rest of the night and had to eat about 70 pieces of raw yellowtail and was throwing up into a trash can.”
10.Seth Rogan and Jason Segel covered Charlie Hunnam in fake blood and hid him in the bathroom. Then, they got Forgetting Sarah Marshall director Nick Stoller to drink a lot of water. Hunnam scared the daylights out of Stoller when he finally had to pee.
11.Cameron Diaz and Leslie Mann drew a mustache on Kate Upton while she was sleeping during a flight.
12.Simon Pegg fooled his Star Trek: Into Darkness costars into thinking they had to wear mandatory "neutron cream" to protect themselves from "neutron damage" on set. Their costars wore the cream on their face, which was actually just unnecessary blobs of plain lotion.
13.Emilia Clarke framed Sam Claflin for stealing her Game of Thrones doll on the set of Me Before You. Claflin retaliated by stealing all of the furniture from Clarke's trailer.
14.Instead of asking about xXx: Return of Xander Cage, Ruby Rose got an interviewer to ask Nina Dobrev only questions about Ruby Rose.
15.Jimmy Kimmel made a whole bunch of fake yard sale flyers for John Krasinski's house (with his real address!) and hung them all over Los Angeles.
16.And Josh Hutcherson put a dummy of a tracker jacker victim from The Hunger Games on the toilet in Jennifer Lawrence's bathroom. She peed herself when she saw it.
Do you know of any other fun celebrity hijinks? Tell us about them in the comments below!