The complete alternate playground lyrics to "Jingle Bells"

Jingle Bells, Batman smells
Robin laid an egg
The Batmobile lost a wheel
And the Joker got away

Batman's in the kitchen
Robin's in the hall
Joker's in the bathroom
Peeing on the wall

This is the song that got Bart Simpson thrown out of the Springfield Elementary Christmas choir in "Simpsons Roasting On An Open Fire" A.k.a. The Simpsons Christmas Special.