Math Concepts With Funny Names

(Some of this came from a Reddit post I read, and some of the comments on it.) Here are theorems with names that I think are funny--- or at least unusual. The names are also pointers to the Wikipedia entry on them or some other source.The Chicken McNugget TheoremThe Ham Sandwitch TheoremThe Hairy Ball TheoremFreshman DreamThe law of the unconscience statisticianThe Homicidal Chauffeur ProblemThe Pigeonhole Principle (We are so used to this we no longer find it funny, but it is.) Eventown and Oddtown I am sure there are more and I invite you to comment BUT there are some issues1) What is funny?2) I want math concepts that are known. As a counterexample, if Lance proved a theorem and called it the Funkytown Theorem just to get on this list then I'd be surprised. It also would not count. 3) The name has to be some relevant to the concept. And I now list two titles of papers that I find funny Note that what I write IS the title, even though the first one is an odd title and the second one…