Crisler's Law 

The law of averages that states that sooner or later in a reason-minded discussion about the Teenage Mutant Ninja Turtles, someone will attempt to refute the entire discussion or argument with a statement equivalent to "But we're talking about four mutant ninja turtles living in a sewer!"

With no leg to stand on in the ninja turtle debate, Jerry invoked Crisler's Law.

Crisler's Law by Kevin Laird December 27, 2011