Lrr: I am Lrr. Ruler of the planet Omicron Persei 8.
Bender: Bite my shiny metal ass!
Zapp Brannigan: If we hit that bullseye, the rest of the dominos will fall like a house of cards. Checkmate.
Fry: That's the saltiest thing I ever tasted, and I once ate a big heaping bowl of salt.
Fry: You named your boil Susan?
Bender: What do you mean "we", flesh-tube?
Fry: You can't give up hope just because it's hopeless! You gotta hope even more, and cover your ears and go blah blah blah blah blah blah!
Zapp Brannigan: Brannigan's law is like Brannigan's love - hard and fast.
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]