Continuity mistake: When it's Nibbler's birthday, in a far away shot of Nibbler in his chair, the three balls on it are pink, but in the close up they are green. (00:04:20)
Continuity mistake: At the beginning of the episode there is tape on the armrest of the couch, but later in the episode there is no tape anywhere on the couch.
Continuity mistake: When Leela is feeding Nibbler there are two drawers and two knobs right behind Nibbler. When it cuts their positions and appearance change. (00:00:55)
Continuity mistake: When talking about El Chupakneebra with the Sewer People, the characters are standing in front of a building with a blue sign reading "Cleaners". But in the shot where Leela explains how Nibbler loves fresh crocodile, the writing on the sign changes to a completely different, much narrower, style.
Continuity mistake: Down in the sewer when Leela and Bender are calling for Nibbler, the patch on their boat changes position between the shots. (00:13:40)
Continuity mistake: When Bender takes the eggs out of the egg box he doesn't close the box. When it cuts the box is closed. (00:05:20)
Continuity mistake: Right at the beginning when Leela is opening Nibbler's food, there is no pipe connecting to the microwave, yet when Bender is attacked there is a pipe. (00:00:55)
Continuity mistake: When the vet is examining Nibbler, there is a table next to the operating table right in the first shot, but when the shot changes it is no longer there. (00:02:15)
Continuity mistake: When Fry, Leela and Bender are in the mutant village they walk past a building which has the sign on it "Dry Cleaners." However, when the shot cuts to the close up, it has suddenly changes to just "Cleaners." (00:15:40)
Continuity mistake: When the mutant with the big head first mentions El Chupakneebra, in the background you can see the blue sign reading "Cleaners". It is then attached to the building next to the one the characters are standing by. However, in the next shot, when Leela asks what El Chupakneebra is, you can see the blue sign on the building they are in front of.
Continuity mistake: Leela's shirt gets fixed when she picks up Nibbler after they defeat the Chupeneabrea. (00:25:45)
Continuity mistake: When it cuts to the bar and Leela is watching Amy dancing with a guy, Amy is resting her head against the man's left shoulder. When it cuts she is resting her head on his right shoulder. (00:10:15)
Continuity mistake: When we see Nibbler sitting on the floor with all the unwrapped papers around him, a purple box is lying on some blue paper right in front of him. When it cuts the box is grey and the paper is green. (00:03:20)
Continuity mistake: When El Chupeneabrea rips off Bender's arms you see Bender standing right next to a metal plate on the ground. When it cuts the plate is gone. (00:19:15)
Continuity mistake: When Leela is at the pub and starts crying, it cuts to Bender who also starts crying. The darts on the wall behind Bender change position between the shots. (00:10:00)
Continuity mistake: When Bender is making the cake, when he gets the ingredients from the fridge, there are a lot fewer items when the shot changes. (00:05:20)
Continuity mistake: When Fry, Leela and Bender goto the vets, when the veterinarian comes out the door is open but when the shot changes it is closed. (00:02:05)
Continuity mistake: When Bender is done baking the cake there is a yellow tissue by the sink. When it cuts the tissue is white. (00:05:50)
Continuity mistake: When Bender is watching television with Fry, in the background you can see the dart in the background is on the top half of the board in the wall, but when the shot changes it is in the bottom half of the wall. (00:10:00)
Continuity mistake: When the professor puts the empathy chip to Bender's head, his grip on the pincers change between the shots. (00:08:30)
Answer: You are thinking about episode 20 of series 2 - "Anthology of Interest I". She technically never kills anyone, but in the episode she ask a "What if machine" (one of the Professor's inventions) what would happen if she was more impulsive. The machine then shows the more impulsive Leela killing off the Professor to get the money from his will and thereafter killing Hermes, Bender, Scruffy, Cubert, Nibler, Amy and Zoidberg to cover it up. Finally she does something really impulsive with Fry.
Andreas[DK]