From the old Abbott and Costello radio show:
Bud Abbott: Costello, do you know anything about lions?
Lou Costello: Do I know anything about lions? ‘Course I know lots of things about lions! One time I went lion hunting in Africa with my brother, and brought back a stuffed lion.
Bud Abbott: What was the lion stuffed with?
Lou Costello: My brother. (pause) You’re not getting me into that cage with that lion, brother!
Bud Abbott: Oh, you’ve nothing to worry about. That lion was raised on milk.
Lou Costello: So was I, but I eat meat now!