Credit: Christopher Polk/KCA2012/Getty Images

Hollywood was seeing green on Saturday night!

At the Kids' Choice Awards in Los Angeles, no celeb, no matter his or her major star power, was safe from host Will Smith's slimy pranks.

Halle Berry should have known better than to make a late entrance at a gig that the 43-year-old actor was hosting. As the newly engaged actress, 45, tried to go unnoticed on her way to her seat, Smith gave her a hard time while guiding her to one in the front row -- where she was covered with a bucket of green slime!

Justin Bieber's sliming was a bit more messy. After he accepted his award for Favorite Male Musician, Smith joined the "Boyfriend" singer, 18, on stage to announce the news that KCA viewers decided Bieber was the recipient of the finale slime!

Holding him tight so he wouldn't run away, Smith also got a gooey, green shower too -- from all directions.

Other stars who got slimed: Glee's Chris Colfer and heartthrob Taylor Lautner.