Not funny! Celebrity jokes that went very, very wrong

We have all heard about pranks on set: George Clooney is famous for joking at the expense of his fellow actors. But what happens when these jokes backfire? We take a look at some of the pranks that didn’t go quite as planned.

Most of us find the Oscars night 2022 hard to forget. Actor and comedian Chris Rock appeared onstage to present the Academy Award for best documentary feature. During his introduction, Rock made a joke about Pinkett Smith's shaved head and her appearance in a 'G.I. Jane' sequel.

Will Smith and his wife Jada Pinkett Smith found it less than amusing. The actress has a shaved head because she suffers from hair loss; it's not a choice. Moments after the awkward joke, Will Smith made Academy Award history.

The actor, who was about to accept his award for best actor, walked onto the stage and slapped the comedian, thus starting 'Slapgate.' He would later issue a full apology but it certainly headlined the evening.

Donald Faison, star of 'Scrubs,' thought it would be hilarious to prank his co-star Zach Braff by having a group of kids pretend to destroy Braff's brand-new Porsche. Perhaps he should have thought it through a bit more.

Faison and the Punk'd crew set the 'joke' up so that when Zach left a liquor store, he spotted a group of adolescents spray-painting his $100,000 sports car.

The idea was that the kids escaped while Zach stood there in amazement, but alas the actor reacted differently and chased one of them down and started beating them as if someone had just destroyed his pride and joy.

On the set of James Cameron's Titanic, there was a party. Well, not technically a party - but definitely qualified in the ‘large gathering’ category where people were eating from the same bowl.

A cheeky prankster, who still remains unidentified, decided to spike the crew's lobster chowder with PCP or, as some call it, angel dust.

The prank resulted in a very sick crew and ended up sending 50 people to the hospital. As we said, nobody knows who was behind the tummy-upset gag, perhaps it was a vengeful ghost of a passenger from the real Titanic?

Katy Perry made fun of Britney Spears' mental health at the 2017 Grammys. While talking about her hair on the red carpet, Katy mentioned that she'd be down to shave her head at some point.

“It’s the last color in the spectrum that I can do, I’ve done all of them and the only thing left to do is shave my head which I’m really saving for a public breakdown,” the singer said.

“I’m down for that,” Perry continued. But as we know, mental health is no laughing matter and as the years rolled by, Britney’s struggles became clearer.

'Ant-Man' actor Paul Rudd tried to pull a prank on co-star Jason Seigal when going to the bathroom on a promotional tour in Canada.

Popping to the bathroom before one particular interview, Rudd assumed his co-star would also need the men's room. Rudd entered first and pulled his pants down to his ankles like a child revealing his bare bottom.

The biggest problem with this story is that the next person to enter wasn’t his fellow actor at all. Rudd stood bare-faced and bare-bottomed in front of a total stranger.

Acclaimed director Oliver Stone, who has won Oscars for 'Platoon' and 'Born on the Fourth of July,' left audience members speechless when he made a joke about the murders of five sex workers in England at an award ceremony.

Stone was presenting the award for best comedy film and began: "It's great to be back in England.” But what he said next stunned the audience.

"I feel, Jack The Ripper days are back. Nothing ever changes here." The audience fell silent. Nothing says comedy like a serial killer.

Rapper The Game convinced 580,000 Twitter followers that calling a certain phone number would help them win the opportunity to try out for an internship working with him.

However, the number he posted belonged to the L.A. Sheriff's Department's Compton station, which was immediately flooded with enough calls to jam the phone lines for two hours.

During which time a number of people in actual need of assistance were calling the police station and weren’t able to get through. The Game's prank, was endangering people's lives. The police were understandably furious and announced they were gathering evidence in order to prosecute The Game. The Game apologized publicly on CNN and police dropped the prosecution charges.

Actor Carlos Bernard, who plays Tony Almeida in the long-running thriller '24', decided it would be hilarious to convince his co-star Mia Kirshner that she was being arrested.

Bernard persuaded two of his police officer friends to show up on set and pretend to arrest his co-star for smoking marijuana outside of her trailer, something that she hadn't been doing.

The prank halted filming for hours, ultimately costing the show a day of production and a lot of money due to Kirshner being totally distraught and thoroughly distracted by Bernard's joke.

In October of 2009, Andrew Sachs, the actor best known for his role as Manuel in 'Fawlty Towers,' was supposed to be a guest on Russell Brand’s and Jonathon Ross’ radio show - but he had cancelled at the last minute. Brand and Ross left four messages on his voicemail claiming Brand had an intimate relationship with Sachs' granddaughter.

To put it simply: two famous strangers were shouting into a 79-year-old man's answering machine, on a nationally broadcast radio show, about having intercourse with his 24-year-old granddaughter.

The BBC received 37,500 complaints from audience members and fined the two hosts 150,000 pounds. Brand ultimately quit the show and Ross was suspended for 12 weeks. Baillie (The granddaughter) describes to the Daily Mail how her grandfather still refuses to speak to her years later.

Mel Gibson was at one point he was one of the biggest stars in the world. Everyone wanted to work with him, and he had a reputation for being an incorrigible prankster. The majority of his pranks however were focused on humiliating his female co-stars.

While filming ‘Forever Young’ with Jamie Lee Curtis, Mel pretended to be a knife-wielding lunatic and showed up at her trailer in a hockey mask. He also gifted a freeze-dried rat to his co-star Helen Hunt on the set of ‘What Women Want’.

While filming ‘Ransom’, Gibson discovered some bare photos of Rene Russo that had been taken when she was a teenager. He had sections of them enlarged to poster size and posted those on the crew bulletin board. Every day, the cast and crew of ‘Ransom' were treated to a different part of 17-year-old Rene Russo's anatomy.

Superstar Rihanna shared a photo on Instagram of a pack of rice cakes decorated with earrings and sunglasses. It all seemed a bit of fun but had dark undertones.

The singer was actually making fun at Chris Brown's then girlfriend Karrueche — who just so happens to be half-Vietnamese.

It's not really what we expect from an icon like Rihanna. And what an outcry might there be if something similar had been done to her…?