It's after the hashtag #puberme was created on Twitter.
Stephen Colbert, who hosts the Late show in America, and actor Nick Kroll kicked off the fundraising challenge.
For every celeb who posts a photo, the Late Show host will donate money to Puerto Rico hurricane relief through his charity, the Americone Dream Fund.
Hurricane Maria was the most powerful hurricane to hit Puerto Rico in nearly 90 years.
Launching the challenge, Stephen Colbert set the bar pretty high.
And soon, other stars were joining in.
Self-proclaimed ladies man, James Corden..
Lena Dunham's especially proud of the spot on her head.
Here's Topher Grace owning it in 1992...
Amy Schumer shared this on Instagram.
Other stars have also been donating money to help victims of Hurricane Maria.
Jennifer Lopez donated $1m (£750,000) to help people on the island.
Rapper Pitbull sent his private plane to Puerto Rico to transport cancer patients to the US mainland.