Revealing mistake: When Cartman walks in on Sally Struthers eating the cake, the cake has holes in it, and part of her hair goes in front, and part of it is visible through the cake. All of the other slices have holes in the same place as well.
Mr. Hankey, the Christmas Poo - S1-E10
Continuity mistake: When Mr. Hankey is dancing around Kyle's bathroom there are some poo marks where Mr. Hankey never even touched.
Mr. Hankey, the Christmas Poo - S1-E10
Character mistake: When the class are practising the nativity, Mrs Broflovski comes in and berates Mr Garrison for casting Kyle in the part of Joseph of Arimathea, but Joseph of Arimathea wasn't the husband of Mary, Jesus' mother, but a disciple of Jesus who helped in the burial of Jesus after his crucifixion.
Mr. Hankey, the Christmas Poo - S1-E10
Continuity mistake: In the scene where Mr. Garrison is telling the students to to get in place for the play, Kenny is seen in the group. Despite the fact that he is supposed to be taking the star or the ceiling at that point. He is then seen seconds later climbing down the ladder with the star.
Mr. Hankey, the Christmas Poo - S1-E10
Continuity mistake: When the town are protesting outside the Mayor's office, the woman at the front of the Nativity protesting group is wearing a purple shirt. A few seconds later, she is with the group against the cutting-down of Christmas trees wearing a completely different shirt (white with a Christmas tree in a red circle with a line through it).
Continuity mistake: When opening presents, the blue mega man disappears instantly. (00:18:20)
Continuity mistake: Halfway through the episode, Green Mega-Man turns into Blue Mega-Man.
Continuity mistake: When Mr. Garrison returns to the classroom with his new face and does the posing to "Shadow Dancing," it flashes back to the students and Wendy is dressed in her normal clothes instead of the black leather she wore to impress Stan. Next time it shows her, she's back to normal.
Continuity mistake: When Stan pukes on to the desk when Miss Ellen says his name at first, it is pink. Then when the camera cuts back to him, it is brown. Then when he pukes the second time and Kyle says "You had waffles for breakfast huh?" it is pink again.
Continuity mistake: While Kyle is asleep in his bedroom the Triangle of Zinthar is on the dresser beside the framed photo, but in the next shot when the cut ceiling falls onto the floor the Triangle has vanished, then it reappears on the dresser where it is supposed to be. (00:07:40)
Cartman's Mom is a Dirty Slut (1) - S1-E14
Continuity mistake: At first the football team is mentioned as "The 1989 Denver Broncos" but throughout this episode and its sequel, they are "The 1991 Denver Broncos."
Cartman's Mom is a Dirty Slut (1) - S1-E14
Continuity mistake: The video sent in by Stans granddad of Kenny getting hit by the train doesn't match what actually happened.
Cartman's Mom is a Dirty Slut (1) - S1-E14
Plot hole: Stan's grandad submits the video of Kenny being hit by the train. This gets through into the final, which shocks Stan and Kyle. But shortly the clip would have had to get through to the final by another episode, so shortly Stan and Kyle wouldn't have been so surprised. The video couldn't have been submitted before, as Stans video was submitted first.
Cartman's Mom is Still a Dirty Slut (2) - S2-E2
Continuity mistake: Chef's car outside Hells Pass Hospital is almost covered in snow the first time it is seen. However a car seen sitting outside the America's Most Wanted studio in South Park a few minutes later has no snow on it whatsoever.
Continuity mistake: The next day after Ike's bris Kenny is sitting in his seat in class but in the next shots of the class he is not there.
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