Seth Rogen says he's fulfilled a dream, and he's not talking about starring in the box-office hit "Knocked Up" or playing a superhero in the upcoming "The Green Hornet."
Rogen co-wrote an episode of "The Simpsons" and lends his voice to a character in the episode that airs 8 p.m. EDT Sunday and kicks off the Fox TV show's 21st season. He's only the second visiting celebrity to both write and act, following in the 2006 footsteps of Ricky Gervais (jer-VAYS').
The episode, by Rogen and writing partner Evan Goldberg, plays off the actor's fitness training for "Green Hornet."
In "Homer the Whopper," Rogen voices a trainer getting Homer Simpson in superhero shape to play Everyman, a comic book hero created by the rotund couch potato.
