A Very Special Family Guy Freakin' Christmas - S3-E16
Corrected entry: At the beginning of the episode, Chris gives Stewie a candy cane, which Stewie immediately begins sharpening with a knife, with the intent to stab Lois with it. But if Stewie had a knife the entire time, why didn't he just stab Lois with that?
Correction: Because stabbing someone with a candy cane at Christmas had more poetic flare.
Xofer