Farnsworth: I can't live forever and I need an heir. Someone to spend my vast riches and take care of my man-eating anteaters when I'm gone. The others simply aren't level-headed enough. They're too impulsive. Not like you. Not like old, predictable, dull-as-dishwater Leela.
Leela: Hello? New boots!
Farnsworth: That's why I've made you my sole heir. The day I die, you'll be a very wealthy woman. Oh, my, yes. Incredibly wealthy. The day I die. Because you're so unimpulsive.