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 series co-creator Trey Parker, along with David Goodman, and directed by Parker. It spoofs the "" episode "Dagger of the Mind". In the episode, the boys visit a planetarium; they soon discover that the operator has sinister intentions involving brainwashing. Meanwhile, Cartman auditions to sing on the Cheesy Poofs advertisement. 
Despite the title, the episode has nothing to do with Roger Ebert (who had given "Orgazmo" and "BASEketball" negative reviews, despite being complimentary of the show "South Park"), aside from a brief joke about a fictional "Roger Ebert constellation" during the tour of the planetarium, and another joke, obscured by other characters speaking over it, comparing the hot gas that composes stars to "what comes out of Roger Ebert's mouth when he speaks".
Plot.
The class goes on a bus trip to the local planetarium. Once arriving, Cartman is tempted by a Cheesy Poofs truck parked outside, auditioning kids to sing the Cheesy Poofs song on their next television advertisement. The kids all think they will hate the planetarium, but after watching the star show, they want to go back again after the field trip. Not only do they go back, but they all also start volunteering to work at the planetarium. This turns out to be because the director, Dr. Adams, is using a brainwashing device on them. While doing so, he describes how stars are made up of hot gas, "which also comes out of Roger Ebert's mouth".
Cartman sings the Cheesy Poofs song and gets selected to sing it on television, after cheating and browbeating his way past the other contestants. Cartman bursts into the classroom to tell his friends that he was selected to sing on the commercial, only to be confronted by Kyle as Kyle creates an on-the-spot Haiku poem about Cartman's chances. Kyle says "I bet you don't win, They don't let big fat asses, perform on TV" in perfect Haiku form (which the children were studying at the time), to which Mr Garrison exclaims "very good Kyle!". Stan and Kyle become concerned about the planetarium's star show. When they have Kenny go and witness the show while Stan and Kyle examine the controls, they casually increase the star projector's power, unexpectedly causing Kenny's head to explode. Stan and Kyle tell Officer Barbrady what has happened; Barbrady is skeptical but accompanies them to question Dr. Adams. Because of this, Dr. Adams brainwashes Barbrady to believe that he is Elvis Presley; he then reveals his brainwashing scheme to the boys: to have people work at the planetarium because nobody finds planetariums interesting.
Meanwhile, school counselor Mr. Mackey and school nurse Nurse Gollum have learned of the mind control device through a child who earlier escaped the planetarium. They race to stop Dr. Adams, and a showdown occurs at the planetarium, with Stan, Kyle, Mr. Mackey, and Nurse Gollum against Dr. Adams and Barbrady. The boys, Mackey, and Nurse Gollum are quickly captured, tied down, and brainwashed into forgetting everything they found out.
However, in the middle of the process, Cartman, upon discovering the other boys missed his commercial, angrily kicks the star projector, sending the full blast of the mind control machine into Dr. Adams' brain. Dr. Adams becomes a mindless shell collapsed against a wall. Cartman is elated that he not only was on television but saved everyone as well. His mother chastizes him for picking his nose again.
Home media.
All 18 episodes of the second season, including "Roger Ebert Should Lay Off the Fatty Foods", were released on a DVD box set on June 3, 2003.