Gigi Hadid, Katy Perry and Michael Phelps celebrate April Fools' Day

— -- Saturday marked April Fools' Day, and some of our favorite celebrities got in on the prank-happy holiday.

Gigi Hadid shared a photo of herself, seemingly sporting a short hairstyle on Instagram.

The model, who normally has long blonde hair, captioned the photo with several scissor emojis, but then added: "happy April foolz fwends ;)"

Rebel Wilson pranked her co-stars and crew while on the set of "Pitch Perfect 3," which is due out Dec. 22.

A video of the incident in which the actress pretended to pass out near her trailer was posted to social media. In it, you can hear Wilson yell, "April Fools!"

Katy Perry joined in on the fun. She posted a throwback photo of herself wearing a sports bra with her hair disheveled.

She captioned the photo, "I'm proud to announce the cover for my 4th album!...Happy April Fools! Been plotting in the same type of sports bra from my IM and laminated calendar since 99'. It's all about the long game..."

Meanwhile, Michael Phelps used Twitter to prank his swimming fans. He wrote: "Some dreams/goals you just can't get rid of...been doing a lot of thinking n I've decided that I'm going 2 make another comeback! #tokyo2020"

Phelps has announced his retirement after the 2016 Olympics.

Nine hours after his post, the Olympic record-holder cleared the air. "#aprilfools I'm not actually coming back?? sorry for getting some of yalls hopes up," he wrote.