Haha, they are clearly SS attack rabbits.
A little known last ditch attack weapon (BTW they failed because a mad scientist misunderstood the 'last ditch' bit and put them in a dug out ditch below the Seelow Heights the day before soldiers clashed there.
Soviet troops discovered them, BBQ them with flame throwers and ate them).
Clearly, Monty Python discovered some info about these obscure SS attack rabbits and latched onto the idea.
Sorry guys, I clearly have low blood sugar ;-)