Mass Bradley asked: Why was Beaver Cleaver called "Beaver" or (my favorite) "The Beav"?
Thank you for the question, Bradley. There are two explanations.
First, the real one: The show's writer, Joe Connelly, served during the war with a shipmate called "The Beaver." When looking for a name for the television character, he chose that.
Second, the television one: The name was explained in the last episode, "Family Scrapbook." Wally could not pronounce his younger brother's name "Theodore." He pronounced it odd, and the parents switched it a little to make "Beaver."
Almost makes you wish you didn't know, doesn't it?