Actor and eco-activist Leonardo DiCaprio went green at Nickelodeon's 2009 Kids' Choice Awards -- but not with slime!

DiCaprio became the first ever recipient of the Big Green Help Award, which celebrates Leo's dedication and contribution to green and environmentally-friendly causes. "Right now, our mother -- our mother -- all of our mothers, Mother Earth is hurting," the "Titanic" star said as he received the award, "And she needs a generation of thoughtful, caring and active kids like all of you to protect her for the future. You can help us win the battle to clean up our air, our water, our land, to protect our forests, our oceans and our wildlife."

"High School Musical 3: Senior Year" nabbed the Favorite Movie award, as well as the Favorite Movie Actress for star Vanessa Hudgens. Disney hunk Zac Efron thanked fans for helping bring the genre back to life during an acceptance speech for the award. "Lately, a lot of people have been taking credit for bringing back the musical," he said. "The truth is we've known who's been responsible for bringing back the musical all along. It was you guys!"

The show's host, Dwayne Johnson, also kept the energy up with various pranks and hijinks throughout the ceremony. Jesse McCartney got squirted with a fake microphone, and presenters Sandra Bullock and Hugh Jackman got slimed before presenting the award for Favorite Book for the "Twilight" series!

The award recipients were chosen by over 90 million votes online. For a full list of the winners, click here!