His guest role in the fourth episode of South Park ("Big Gay Al's Big Gay Boat Ride") that was an early indicator of its brilliance: In a subversion of the celebrity guest star spot, Clooney's role was not a speaking part, but rather simply providing the barks for Stan's dog. The role was designed as a Take That towards shows that had a high frequency of celebrity guest stars (particularly The Simpsons). Originally, the role was sent out to Jerry Seinfeld, but he and his agent turned it down because of the lack of dialogue. On the flip side, Trey Parker said that Clooney (who was already a vocal supporter of the show even in its infancy) got what they were aiming for and signed on. Understandably, Comedy Central was excited about the prospect of a George Clooney guest spot but were disappointed that his role was minor.