The Mook, the Chef, the Wife, and Her Homer - S18-E1
Continuity mistake: Just as Otto is about to put in the grand funk tape you can briefly see an different tape in the recorder. Slow motion is not needed but a sharp eye is.
The Mook, the Chef, the Wife, and Her Homer - S18-E1
Continuity mistake: When Bart and Fat Tony's accomplices are going to meet Krusty, Krusty's nose can briefly be seen as white when it should be red.
The Mook, the Chef, the Wife, and Her Homer - S18-E1
Continuity mistake: When Lisa grabs Ottos tape recorder her necklace is orange but when she gets off the bus it is white.
Please Homer, Don't Hammer 'Em - S18-E3
Continuity mistake: It is revealed that Bart is very allergic to shrimp. However, in "The Frying Game" (where Marge and Homer get "framed" for a murder and end up on "Frame Up"), Bart says he was in the green room and that he "ate so much shrimp."
Please Homer, Don't Hammer 'Em - S18-E3
Continuity mistake: As the workmen begin to leave site after hearing that Homer is unable to pay them, a couple of tools are dropped on the ground; however, in the following shot, facing back towards the cabinet where Homer is hiding, the tools have disappeared.
Please Homer, Don't Hammer 'Em - S18-E3
Continuity mistake: In this episode Principal Skinner breaks into Bart's doctors office to find out if Bart has a 'kryptonite'. Bart discovered Skinner was allergic to peanuts. On Bart's medical history form under 'known allergies' it has shrimp ticked (they later battle with shrimp and peanut on a stick). However in a previous episode (The Heartbroke Kid, season 16 episode 17) it was discovered that he was allergic to cauliflower, so that should have been on the list as well.
Continuity mistake: When Homer is eating donuts while everyone is doing push-ups, his donut stays the same size every time he bites it.
Continuity mistake: When Marge enters "Your home from space" the address is still http://www.google.com, then the shot changes to Marge outside and then shows the computer again where the address is now http://yourhomefromspace.com.
Stop Or My Dog Will Shoot - S18-E20
Continuity mistake: In the scene where the dog chases Snake into a playground, Santa's little helper starts pulling the ropes off the top of the climbing frame, in one shot the dog has two ropes left but when we see Snake the dog chews through one rope and the whole thing falls.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.