Continuity mistake: When Dr. Zoidberg walks out of the bathroom, he zips up his shirt, and the zipper is just visible above his buttoned up jacket.After that, it's not seen in this episode or ever again. (00:01:45)
Continuity mistake: When Bender starts talking about Clem Johnson at the baseball game, his bottle is empty, but in the next shot it is half full. (00:03:05)
Continuity mistake: When Hermes first brings in the package of lugnuts the address is on two lines, the "To:" and "Chapek 9", but after that shot the address is all on one single line, - "To: Chapek 9". (00:04:35)
Other mistake: When the robots are building a Tetris wall, there is a section on the left made up of two red 'L' bricks. However, the upright L block is not the same as the other red blocks, because it is flipped laterally. (00:09:05)
Continuity mistake: In the scenes with the robot elders, the colour of the Elder's eyes change frequently between shots.
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]