Prank You Very Much! Celebrities' Funniest April Fools' Jokes

Sandra Bullock and George Clooney were at a dinner party when he tricked her into jumping into the pool — alone.

"I went to the bathroom and came out and there was George and someone else going, 'We're gonna go in the pool,' and I was like, 'Really?'" she recalled. "And so I held their hands and on the count of three … I jump, and they let go, and I go in the pool."

She added, "The sad part was I wore this cute little lace dress that I paid a lot of money for, and as I got out, it started disintegrating."

The good-living goddess left her camera crew in shock when she suddenly collapsed to the ground while filming!

When they rushed to her side, Martha Stewart held a towel covered in blood to her head. But before they could haul her up and get her to the ER, she shouted "April Fools!" leaving them shocked and speechless. She'd pulled the prank with red food coloring.

LeBron James fooled Blaze Pizza customers when they walked in and did a double take after they saw the famous basketball player towering over his "coworkers." When people asked if he was James, he pretended he didn't even know what basketball was!

He was almost caught when a customer pointed out he looked "very familiar," comparing him to fellow NBA legend Dwyane Wade.

"I get that a lot," he replied. "I've heard of that guy too."

Virgin Group co-founder Richard Branson was almost arrested after he flew a hot air balloon disguised as a spacecraft over London — complete with a fake alien.

Motorists were stunned after seeing the UFO with flashing lights floating over the highway. Cops raced to the scene, and they weren't amused.

"It was lucky a serious accident did not occur," fumed Chief Inspector Andrew Neilson of Surrey police headquarters.

When the balloon landed, a person dressed up as an ET emerged — before spotting the police and running back inside.

"To begin with, the police didn't see the funny side of it and threatened to arrest us for wasting their time," said Branson. "Thankfully, they soon joined in the fun and left with smiles on their faces."

Ashton Kutcher — host of MTV's Punk'd — got a team together to pose as government officials in the midst of repossessing Justin Timberlake's home and all of his belongings, including his dogs!

The concerned pop star, then 22, called his mother and ended up crying on the front porch of his home! After a few minutes of harassment from the lead IRS agent, played by Dax Shepard, Kutcher came out to let Timberlake know it was a joke.

Talk show host James Corden was proud as punch when he delivered a statue of David Beckham to him. But when the former soccer star took the cover off in a "special moment that I'll be able to share with friends and family," he was less than impressed and branded the sculpture so "embarrassing" that he ordered the film crew to stop the cameras!

But Corden couldn't contain his laughter as he watched the sports icon's fury at the ugly statue that was supposed to be him. Only instead of Beckham's handsome mug, it was an ugly guy with three teeth, a long chin and a giant b---!

Finally, Corden — who was laughing so hard he could barely speak — walked on set to say the glittering statue was a fake.

Game of Thrones star Kit Harington shocked wife (and fellow GOT star) Rose Leslie by placing a prop from the show — a fake severed head — in their refrigerator for her to find. She (understandably) screamed!

One year for a post-April Fools' Day prank, Nicole Richie had her friend pretend to be a police officer and wake Lionel Richie up from a dead sleep at 4 a.m. to tell him Nicole had been arrested.

When telling the story on Jimmy Kimmel Live!, Nicole said, "At the time it didn't go over well, but it's one of his favorite stories!"

Jimmy Kimmel has built a reputation as a prankster, so songstress Rihanna decided to turn the tables on him.

She snuck into his house after conspiring with Jimmy's wife, Molly Kimmel, who was in on the April Fools' joke. The singer leapt into his bedroom while he was sleeping and launched into a rendition of her song "B---- Better Have My Money," while raining dollar bills onto him.

The performance was complete with backup dancers, confetti, flashing lights, giant speakers and pillow throwing. Jimmy woke in shock and confusion — but later had a good laugh at his own expense.

When they were starring in Kingsman: The Golden Circle, Taron Egerton put a mannequin on Channing Tatum's trailer bed with a wig on it and some empty wine bottles and a pair of high heels on the floor, laughing, "He came in one morning and thought there was a person in there and he was quite freaked out."

But Tatum got him back: "The day he left, he filled my trailer with I think it was about 20 s-- dolls and some rather disturbingly large prosthetics!"