Chris Polk / Kids Choice Awards
Katy Perry wasn't supposed to open the slime-rigged box. It was her co-presenter Jonah Hill's job, at least until he revealed he had lied to her about it being his birthday. Appalled by his dishonesty, she decided to crack open the box and announce the favorite actress winner herself. Instead, she took a high-pressure sliming to the face. The "Teenage Dream" singer slipped to the floor then clambered up and gave Hill a big gooey hug.