Watch Zach Galifianakis Perform Comedy for Preschoolers

Zach Galifianakis hasn't always been a comedy superstar -- before 'The Hangover,' Galifianakis was just a piano-playing comedian who managed to get a very short-lived show on VH1.

Before 'Late World With Zach' was canceled, this clip was filmed. It's Galifianakis performing for a bunch of preschool students. Not surprisingly, he kills. There's a reason he's so popular now. Enjoy!