S19, EP4 "La Famiglia Guy"
When Joe asks Peter to be the godfather to his daughter, Peter commits to his mistaken interpretation of the role so much that he becomes a real gangster.
S19, EP3 "Boys & Squirrels"
Peter injures himself and a family of squirrels in a chainsaw accident; Chris and Stewie try to nurse one of the injured rodents back to health; a chiropractor fixes Peter's injury by realigning his spine -- and restoring him to his "true height."
S19, EP2 "The Talented Mr. Stewie"
Stewie breaks up with Rupert after learning that he used to belong to Chris; unable to get over his feelings of betrayal, Stewie decides to take action.