In this episode, Stewie finally meets his match: a little girl named Penelope (voiced by Cate Blanchett) who is really, truly a homicidal maniac.
This reminded me of: the South Park episode where Cartman wins a game of "Who's More Hardcore?" with Bart Simpson.
Cartman: What's the worst thing you've ever done?
Bart: I stole the head off a statue once.
Cartman: Wow, that's pretty hardcore. Geez. That's like this one time, when I didn't like this kid? So I ground his parents up into chili and fed it to him.