The simplest and most widely known Monty Python image I can think of is a dead parrot. So maybe an upside-down parrot? Could be nice and colorful too, not to mention memorable.
It is true that many won't make the connection between some kind of Monty Python image and the Python language, as they wouldn't even recognize the image. Outside the UK Monty Python isn't quite so popular as some may think. -- http://mail.python.org/mailman/listinfo/python-list
