Mad As a Hatter
A mad as a hatter is a person who is super good at something, usually a team name, and looks like a giant, angry, bald guy with a mustache.
My team is called the Mad Hatter because we're all angry and bald.
My uncle joined the Mad Hatter team because he thought he was a superhero.
My brother's team is the Mad Hatter because they all wear hats and yell a lot.