This is a perfect thread for something that's been hurting my poor brain for a while.
I heard a joke once, and I remember a bit about it, but the punchline is the killer (and what makes this thread bring it to mind):
"..and THAT, Your Honor, is how a 15-year old girl wound up in my hotel room." Anybody know which one I'm talking about? It involves something turning into a girl suddenly right before that line, but I can't remember how it sets up.