Richard Steven Horvitz

Richard Steven Horvitz (born July 29th, 1966) is an American actor and voice actor. He has been known for voicing neurotic or mentally unstable characters, such as Zim from "Invader Zim". He's also the voice of Billy in "The Grim Adventures of Billy and Mandy", Daggett in "The Angry Beavers", and Kaos in "Skylanders".