1. A person who is a twat to everything and anything that moves into their line of sight.
2. someone who has been defined as a twat, but goes above and beyond the duties of a regular twat.
Mayor McTwat usually resides in doucheville population him.
"Man, Zach needs to go be Mayor McTwat somewhere else..."
"Why don't you go back to your cushy desk job as Mayor McTwat of doucheville, population you."