Every George Clooney Celebrity Prank, from Giving Meryl Streep Acting Tips to Pooping in Richard Kind's Litter Box

When He Posed As Brad Pitt to Pitch Tom Cruise An 'Interview with the Vampire' Sequel

During his Sept. 17 appearance on Jimmy Kimmel Live!, Clooney revealed he's had some fun sending people letters with the Brad Pitt stationary Kimmel gifted him some years back.

"The Brad Pitt one was brutal. I sent it to Don Cheadle," he said, as he began listing all the people who've been on the receiving end of his faux letters. "I sent it to Tom Cruise, saying they want to do [Interview with the Vampire 2], but this time Brad wants to play Lestat," Clooney said with a sly smile.

According to Kimmel, the ruse worked. "Brad this afternoon said that Tom called him and said 'Yeah, it's cool, you can play Lestat, that's fine, I'm okay with that,' and he was like, 'What are you talking about?'"

When He Got Matt Damon the 'Sexiest Man Alive' Cover

As a two-time PEOPLE's Sexiest Man Alive winner, Clooney felt more than equipped to nominate the next generation. He just used some unconventional methods.

"If you live in Hollywood, there were two entertainment papers — Variety and The Hollywood Reporter — [where] you'd see during the Oscar campaign 'For Your Consideration for Best Actor,' and every page was a picture of the actors," he said.

"So, I took out ads with Matt Damon — remember he wore this green Speedo in The Talented Mr. Ripley — I took that picture of him and very seriously said , 'For Your Consideration: Sexiest Man Alive.' "

"And we just kept pummeling it for, I don't know, two years," he recalled. "They finally gave it to him."

When He Pranked Meryl Streep to Get Back at Brad Pitt

Clooney apparently got a taste of his own medicine when he, Pitt and Damon were filming Ocean's Twelve. As the story goes, the gang was in Italy filming and Brad Pitt printed posters telling crew members Clooney only wanted to be addressed as "Daddy Ocean" and warning readers: "don't look him in the eye." But since it was in Italian, Clooney didn't clock the prank. When it was revealed, Damon said it was the "maddest I'd ever seen him," while chatting with CNN's Chris Wallace.

Clooney got back at his friends by using stationery Jimmy Kimmel had given him with Brad Pitt's letterhead, in order to send "letters to actors from Brad Pitt."

One such special delivery? Sending legendary actor Meryl Streep "a giant folder of 60 CDs" to teach various accents, with a note from "Brad Pitt" advising that she listen to it to help with her performance as Margaret Thatcher.

"[Meryl] is like the greatest actor of all time, so I sent it to her," Clooney said. "This package of 60 CDs of accents for the stage and screen and it [had] a card from Brad that said, 'Dear Meryl, I hear you're gonna play the Iron Lady, this guy helped me with my accent in Troy.'"

When He Pooped in Richard Kind's Cat Box

This one is much better told straight from the horse's mouth, but the crux of the story is that Clooney was crashing at Richard Kind's place back in the day. The Spin City actor had a cat at the time and wasn't very good about cleaning out the litter box. Clooney, who had been doing all the heavy lifting for days on end, saw an opportunity to deliver a very crappy — albeit hilarious — lesson on the importance on keeping up with the litter box maintenance.

You can probably fill in the blanks.

When He Tried to Sabotage Matt Damon's Psyche

In the chat with Chris Wallace, Damon recalled the Monuments Men set being another fertile ground for Clooney's elaborate pranks.

Wallace asked Damon, "George Clooney once told me that in the movie The Monuments Men he had the wardrobe people take in your uniform each week so that you would think that you were getting fat. One, is that true? And two, did it work? And three, did you ever get him back for it?"

"First of all, you know George, so you can answer the first question. 'Is it true?' Of course, it's true," Damon replied. "He totally did that. I've never tried to get George back for anything because I just know the countermeasures are gonna be so severe."

When He and Julia Roberts Moved Richard Kind's Bed Into a Casino

It seems Richard Kind makes for an easy target.

Kind came to visit his old pal while he was filming Ocean's Eleven in Vegas, but ended up falling asleep one night as everyone was still "drinking and chatting." Needless to say, it was a big mistake. Huge!

Clooney, along with Julia Roberts, Matt Damon, Brad Pitt and Don Cheadle decided to move the cot Kind was sleeping on into the casino. You snooze, you lose ... the right to a peaceful night's rest, apparently!

When He Got Noah Wyle Added to Steven Spielberg's Naughty List

Noah Wyle worked with Clooney for years on ER, and though Wyle previously toldStill Here Hollywood podcast host Steve Kmetko that he decided to be an "accomplice rather than a victim" very early on, no one in Clooney's company was ever safe.

While on the Tonight Show with Conan O'Brien, Wyle revealed that one year, Spielberg (who was a producer on ER) got the entire cast cellphones as a wrap gift for the season. The only problem was, the previous year, he had given the cast of the film Always slightly bigger wrap gifts: Mazda Miatas.

Seeing an opportunity for a tongue-in-cheek moment, Clooney convinced Wyle and some other ER castmates to write thank-you notes that read, "Dear Steven, Thank you for the Miata cell phone."

Wyle followed through with sending the note, but the mastermind behind it all did not. "I wrote that letter and that was the last Christmas present I ever got from Steven Spielberg," Wyle joked.

When He 'Got Back' at Tina Fey and Amy Poehler for the Golden Globes

It seems Clooney can dish it but not take it.

After Tina Fey and Amy Poehler (pictured on Clooney's lap in 2013) took a jab at him in their opening monologue at the 2015 Golden Globes, the veteran actor decided to get them back. In typical Clooney fashion, he incorporated another unsuspecting celeb: Matt Damon.

As it turns out, the Hail, Caesar! actor sent the two besties some sort of "wounded letter" on behalf of Matt Damon, stating that he didn't appreciate the jokes they had lobbed at him and Clooney in the film's monologue

Ever the industry pros, Fey and Poehler hit back with a prank of their own, which included a letter of warning to Clooney urging him to "step it the f--- up" if he is going to prank "grown-ass, professional comedians."

When He Would Spray Ryan Gosling with Water During 'Ides of March'

Ryan Gosling found out the hard way what it's like working with a master prankster.

While Clooney was directing The Notebook actor in The Ides of March he often found himself with wet pants.

"He will come up to you and tell you something very serious … and then he’ll walk away and you realize your pants are wet,” Gosling told Extra, per The Hollywood Reporter. “He’s had like an Evian spray bottle. He’s been spraying your crotch the whole time."

Still, Gosling had nothing but the fondest things to say about the ER alum and their time together. "He’s hard to be around, so handsome, smart, charming, funny,” he told the outlet.

When Julia Roberts Got Accidentally Caught in the Crossfire

Julia Roberts was pregnant when the crew was filming Ocean's Twelve, so she was being treated like she was "made of porcelain" for the bulk of the production. So she was as surprised as anybody to find an enormous bronze statue put in her suitcase, making it impossible to carry.

She was initially upset by the development, until she heard what happened: The film was moving production from Como to Rome and Brad Pitt, being a gentleman, escorted Roberts' bags for her. Clooney, however, thought the suitcases were Pitt's and put the heavy object in the bag to get Pitt instead.

No word on how Roberts reciprocated.

John Krasinski

George Clooney directed John Krasinski on the set of Leatherheads, and he not only gave the Office star acting advice, but he also indoctrinated him into the art of pranking your costars.

While speaking to his Office costar Jenna Fischer on her Office Ladies podcast, he admitted to having repurposed a prank Clooney played on him while filming an episode of their TV show.

"You and I had this scene where we had to drive up to the farmhouse several times, and we’re doing it and I am getting increasingly more hot ... we had to turn off the AC for sound, and you were like, 'Yeah, I don't know, I'm okay. But you're hot, huh?' " Fischer recalled. "This went on for like 15 minutes, and then all of a sudden you start snickering. You had turned on my seat warmer all the way to the hottest setting!

“You know what’s sad about that prank? I realized that I am such a bad prankster that I stole that prank from Clooney," Krasinski confessed. “That’s how unoriginal I am. Basically you got Clooney’d is what you got.”

“Oh my gosh,” Fischer said, laughing. “I got a recycled prank.”

Mae Whitman

During an interview with PEOPLE, Mae Whitman recalled playing Clooney's daughter in One Fine Day, and all the attendant hijinks that went along with that experience.

"We had these cats and the whole point [in the movie] is we end up taking a kitten with us and we run around the whole city with this kitten,” Whitman recalled. “The props department made these really expensive, beautiful, real-looking rubber kittens that I could hold that wasn’t, like, a real cat, and George Clooney is the biggest prankster in the world. In these busy city streets, he would take these cats and toss ’em off into the street. They’d be getting run over by stuff. He’d play catch with them. Just, like, horrible. So badly that the ASPCA was called and literally came and was like, ‘You’re really throwing cats in the street.’ And he was like, ‘I’m actually not; it’s a horrible misunderstanding.’ But he got away with it for a pretty long time.”