Roger Ebert Should Lay Off the Fatty Foods

"Roger Ebert Should Lay Off the Fatty Foods" is the eleventh episode of the second season of the American animated television series "South Park". The 24th episode of the series overall, it originally aired on Comedy Central in the United States on September 2, 1998. The episode was written by Trey Parker, along with David Goodman, and directed by Parker. In the episode, the class goes on a bus trip to the local planetarium. Once arriving, Eric Cartman is tempted by a Cheesy Poofs truck parked outside, auditioning kids to sing the Cheesy Poofs song on their next television advertisement. Cartman makes fun of film critic Roger Ebert (voiced by Joe Pesci) when he is revealed to be the owner of Cheesy Poofs.
Plot.
Eric Cartman, Stan Marsh, Kyle Broflovski, Kenny McCormick, and the rest of their class go on a trip to the planetarium. They learn that the planetarium scientist is using the projector to brainwash people.