The Tooth Fairy's TATS 2000 - S4-E1
Other mistake: Cartman is excited because the "tooth fairy" left him two dollars in exchange for a tooth. When he holds up the two bills, they are identical. Both have the same serial number.
South Park (1997)
1 other mistake in season 4
Starring: Trey Parker, Isaac Hayes, Matt Stone, Mona Marshall
Cartman Gets an Anal Probe - S1-E2
Continuity mistake: In the classroom there is a poster of The Laughing Cavalier in the back wall in the class. In the last shot of that scene you can notice that the poster has disappeared and is replaced with an astronaut poster. (00:09:05)
Cartman Gets an Anal Probe - S1-E2
Cartman: How come everything today has involved things either coming in or going out of my ass?
Question: Forgot the episode and the season, but does Mark, the kid that gets home schooled and ends up beating Kyle, ever show up in later episodes?
Answer: He appears in at least 5 other episodes, but usually just as a background character. He can be seen at Cartman's party in "Immaginationland". He was also one of the kids trying out to replace Butters in the "Professor Chaos" episode.
Bishop73