Other mistake: After Lisa has made Bart leave the baseball team, Lisa and the rest of the baseball team are having pepperoni pizza at Luigi's. Lisa is also eating the pepperoni pizza. However, Lisa is a vegetarian, so why would she eat pizza with meat on it?
Other mistake: In the credits, Kristen Schaal is misspelled Kristen Schall. (00:20:40)
Other mistake: When Bart is looking at space through his telescope, Earth can be seen through the telescope despite him being on Earth.
Who Shot Mr. Burns? (1) - S6-E25
Other mistake: In the very first scene, when Principal Skinner is opening the door to the school, there is no name on the school. (00:00:25)
Other mistake: In this episode, Smithers' skin is brown, however in future episodes, his skin is yellow. (00:05:00)
Brother Can You Spare Two Dimes? - S3-E24
Other mistake: On the DVD, when Homer is sitting on the Spinemelter, he says at one point "I've tried to fill it with family, religion, community service, but those were dead ends. This card is the answer." However the subtitles say "I've tried to fill it with family, religion, but those things were dead ends. This card is the answer", leaving "community service" out.
Suggested correction: It is very common to shorten the subtitles so viewers don't have to read much.
Other mistake: When everyone is eating the boar at the end, the boar is completely intact, yet everyone except for Lisa is seen with a piece of it. (00:20:30)
Tree House of Horror IV: The Simpson's Halloween Special IV - S5-E5
Other mistake: When Bart says the picture of the school bus is actually called The Ghoul Bus, Lisa points out the name tag says The School Bus. If you closely at the name tag, you can see nothing is written on it.
Other mistake: When Moe is rolling his eyes after saying it was the first time he poured beer into the water supply, Herman's face is drawn incorrectly.
Other mistake: When Homer throws his beer bottle in the air and puts the gun in his mouth, the beer bottle never lands. (00:15:30)
Other mistake: When Ned Flanders is calling Marge and Reverend Lovejoy from the Leftorium, he says that the three hooligans are in the shop on their motorbikes. But a few minutes before when Ned goes outside the shop to tell the boys to clear off, their bikes are nowhere in sight.
Other mistake: When Sideshow Bob leaves Selma to watch MacGyver, the room opposite is 350. Later when he is being taken away by the police there is a room 44. It's unlikely these two numbers would be on the same floor.
Tree House of Horror II: A Simpsons Halloween - S3-E7
Other mistake: As Kang and Kodos fly away from Earth in their spaceship, you can see that the Earth has been coloured wrong. The continents are blue, and the sea is green.
Other mistake: When Nelson puts the intestine into the model's mouth, the size of the gut should not increase. It is the same amount of stuff going in a cycle, so where does all the stuff come from? (00:03:15)
Other mistake: The amount of gunk that come from Bart's model at the start is not proportionate to the size of the model. In other words, there couldn't be enough gunk to cover the entire inside of the bus.
Other mistake: At the finish line, the crowd are missing all their appearance features such as faces, hair etc. (00:13:50)
The Day the Violence Died - S7-E18
Other mistake: At the end of the episode Lisa and Bart watch Itchy and Scratchy in the TV room, which is beside the kitchen at the back of their house. The TV room has a window that faces the backyard, with the record player on a shelf in front of that window. The problem is when Bart looks out the back window and sees Lester skateboarding past the house, the view outside is actually the street in front of the Simpson house, not their backyard as it should be.
Other mistake: At the concert when Bart throws the Frisbee into the dude sat next to him, the crowd in the background are all missing their eyes. (00:03:50)
Other mistake: In the scene set in the future after Lisa, as the US President, held a conference with some journalists, just before the scene changes they show a black journalist with eyes not drawn among the crowd.
Other mistake: When Homer pretends to read the newspaper, the back page is very noticeably blank and missing any print. (00:08:00)