Knock knock!
Who’s there?
Queen
Queen who?
Queen yourself, I can smell you through the door.

Explanation:  This knock-knock joke comes from GRIN:) at http://goodriddlesnow.com/jokes/by/knock-knock-jokes.

It is funny because it plays on the similar sounding words “queen” and “clean.”  The listener expects something related to a queen knocking at the door.  Instead, the listener hears an order to get “queen,” rather “clean.”  It is as if the speaker does not speak clearly, like the cartoon character Elmer Fudd who is always outwitted by Bugs Bunny.