Jingle Bells. Batman Smells.
Robin's flown away.
The batmobile has lost a wheel
and Alfreds eating hay...

Was our version. Last line never quite made sense to me but what the hell!

We also did

While shepherds washed there socks by night and
God rest ye Gerry Mentlemen.

Ahhh. Happy days;-)

Cheers

Dave the Gnome