
Cartman Gets an Anal Probe - S1-E1
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-E1
Continuity mistake: Mr.Garrison's glasses change throughout shots, from a thin pair to a bold pair.
Cartman Gets an Anal Probe - S1-E1
Continuity mistake: The stars keep changing position (especially the sparkly big one) when Cartman is tied to the tree. (00:18:05)

Cartman Gets an Anal Probe - S1-E1
Continuity mistake: In the classroom scene where Kyle tries to be excused from class to find Ike, Cartman sets Pip on fire as he was sitting just behind him to the the left. However in the previous shots Pip had not been sitting there, some other kid was and wouldn't have had enough time between shots to move. (00:09:05)

Cartman Gets an Anal Probe - S1-E1
Continuity mistake: After Stan vomits from Wendy talking to him at school, the vomit disappears in a few shots. (00:10:55)

Cartman Gets an Anal Probe - S1-E1
Continuity mistake: When the boys are first seen in the cafeteria, Stan is in front of Cartman. When Kyle says, "Hey look, there's Wendy Testeburger." in the next shot, Stan is now behind Cartman. (00:10:05)
Continuity mistake: When we see Kenny from the front, the hole in his head exposing his brain appears on his left side, but when we see the top of his head when he is biting people, the hole is in the back of his head.
An Elephant Makes Love to a Pig - S1-E5
Continuity mistake: When the boys are standing in a group, Kenny disappears after a while, then Stan disappears, but then a second later, they are all back together.
Continuity mistake: After Mr Garrison announces Kathie-Lee will be presenting an award for Cartman, you see the next scene in the Mayors office. There we can see cleary the curtains are red, then she looks out the window and looking in the office from outside, they are pink, but it goes in the office again and now they are back to red.
Cartman Gets an Anal Probe - S1-E1
Audio problem: After the scene where Mr. Garrison says, "You can say that again, Mr. Hat," Kyle shouts, "Give me back my brother you stupid aliens" in Stan's voice.
Revealing mistake: When Jimbo asks the children if they want beer, the campfire stays still for two shots.

Cartman Gets an Anal Probe - S1-E1
Revealing mistake: When Cartman finishes talking about his nightmare in the beginning, Chef comes and you can see his hat poking out of the roof of the car. They couldn't really fix this because this episode was done out of construction paper. (00:04:10)
Continuity mistake: When Ned, Jimbo and Kenny are out on the fishing boat they have a rocket attached to a rack. After firing the rocket the rack still remains, but in the next shot when they head for shore the rack is gone.
Deliberate mistake: When the boys are hunting in the forest, then they start to crawl after the rabbit, however, the background behind them is static as if they were crawling in place.
Continuity mistake: The clock behind the geologist shows different times between scenes.
Mr. Hankey, the Christmas Poo - S1-E9
Continuity mistake: When Mr. Hankey is dancing around Kyle's bathroom there are some poo marks where Mr. Hankey never even touched.
Continuity mistake: Just before Warsog emerges from the network building for the first time, Mrs. Marsh is shown to be stood next to a couple of random townspeople. In the very next shot Mrs. Cartman, Mrs. Broflovski and a third nondescript have appeared.
Continuity mistake: In one shot, the security guards are on the ground surrounding Kathie Lee, and in the next shot, they are on the truck.
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