In The Simpsons episode "Treehouse of Horror II", there is a short clip of Johnny Carson doing his Carnac the Magnificent bit. For those unfamiliar with this bit, Johnny (Carnac the Magnificent) holds an envelope up to his head as if he's reading it through ESP and says the answer to a question inside the envelope.
In the Simpsons version, we hear the first part of the bit but then the camera pans away and we never hear the punchline.
The portion we hear Carnac read is:
Geraldo Rivera, Madonna, and a diseased yak.
My question is, what is the punchline? Or maybe there isn't one?