Daniel Louis Castellaneta is an American actor, comedian and screenwriter. He is best known for voicing Homer Simpson on the animated series The Simpsons (as well as other characters on the show such as Abraham "Grampa" Simpson, Barney Gumble, Krusty the Clown, Sideshow Mel, Groundskeeper Willie, Mayor Quimby, and Hans Moleman). Castellaneta is also known for voicing Grandpa in Nickelodeon's Hey Arnold!, and has had voice roles in several other programs, including Futurama, Sibs and Darkwing Duck, The Adventures of Dynamo Duck, The Batman, Back to the Future: The Animated Series, Aladdin, Earthworm Jim, and Taz-Mania. In 1999, he appeared in the Christmas special Olive, the Other Reindeer and won an Annie Award for his portrayal of the Postman. Castellaneta released a comedy album I Am Not Homer, and wrote and starred in a one-person show titled Where Did Vincent van Gogh?