Tree House of Horror XII - S13-E1
Continuity mistake: In "Wiz Kids", Bart stabs Montymort in his shin which is open (i.e. not covered by what he's wearing). Only a little blood pours out. Then Monty raises his shin into shot and there is not only a puncture in the leg of his clothing, but the wound is covered in blood. When he falls, and Slithers eats him moments later, there is no damage at all. (00:19:55)
Continuity mistake: When Skinner is addressing the class before the meat video we first see him with black trays on the desk to the far right. In the next shot they're much closer to him.
The City of New York vs. Homer Simpson - S9-E1
Continuity mistake: When the camera pans down the Trade Center, there is no washing line there. But a few shots later, a washing line appears.
Factual error: When you see Ned Flanders put the earth back inside the hole, he puts it back in much faster than is possible. In one shot, he is only just starting to put it back in, then you see Bart who talks to himself for a few seconds, then back to Flanders, who has finished burying what is later to be revealed as the plant that he (Ned) drowned.
Continuity mistake: At the beginning, when there is an overhead shot of the Simpsons' lawn, the broken lawn mower has disappeared. (00:01:20)
Continuity mistake: When Homer is in his mansion watching Weird Al's parody of his song, the trash on his floor (frappuccino cups, pizza boxes, etc.) keeps switching places.
Continuity mistake: While Homer is sleeping, the fire burns off the hair on his head. But when he wakes up and jumps up off the couch, his hair is back again. (00:17:00)
Continuity mistake: All of the cigarettes that Moe has smoked disappear from the floor after Marge has spoken to him.
Fat Man and Little Boy - S16-E5
Continuity mistake: When Homer goes to see Mr. Gladwell, in one shot, there is no plastic vomit, then a few shots later there is. (00:19:45)
Treehouse of Horror XV - S16-E1
Continuity mistake: When Professor Frink is showing everyone the giant capsule, in nearly every different shot the colours of the balls change. (00:14:50)
Continuity mistake: After the "sponge incident," Bart is standing in the drive with the sponge packet in his hand. In the next shot he says "everything about me must go," but the packet has vanished from his hand.
Realty Bites - S9-E9
Continuity mistake: When Marge finds out the Mr Hutz does real estate, the 'For Sale' sign changes from black to red and then back again.
Skinner's Sense of Snow - S12-E8
Continuity mistake: When the hamster Nibbles has rolled back to Skinner, it takes the lid of the ball off, and the lid lands on the ground. When the hamster is rolling away from Skinner it doesn't put the lid back on, it just leaves it on the ground, but in the next shot the lid is suddenly gone.
Other mistake: Apu already knew Homer because in the flashback episode, Homer's Barbershop Quartet, they were in a band. However, in the scene where Homer enters the Quick-E-Mart, Apu refers to Homer as steady customer as if he didn't know him.
Continuity mistake: Just after Homer has used the proton accelerator, Dean talks to him. In this scene he is writing something on a piece of paper, but he writes on the same line every time. He finishes writing on that line, then starts on it again.
Tree House of Horror XII - S13-E1
Continuity mistake: At the end of 'Wiz Kids', when Lord Montymort is defeated, he falls to the floor, breaking all the floorboards. Then when Lisa takes off the headset, all the floor is intact. In the next shot, the floorboards are all broken again. (00:20:05)
Treehouse of Horror XV - S16-E1
Continuity mistake: When Bart and Lisa go into Mao's, we see above Moe there is a guy wearing a red jacket, then when they're walking past him, he is wearing a light brown jacket. (00:11:00)
Continuity mistake: While Bart is watching wrestling as Marge and Homer are struggling to do the dishes, the buzz cola can he is holding suddenly switches hands between two shots as Lisa is talking to him.
Continuity mistake: In the Itchy and Scratchy cartoon 'A Briss Before Dying', Itchy throws Scratchy's eyes out of the window, but after putting the rest of his body through the grinder the eyes are back.
