Whether you're the Master, the Brat, or the Mouth of the table; earning a nickname is part of the hazing ritual of the poker fraternity. We all probably know a "Mr. Conservative," but some nicknames are a little more outside the box. I like "Slot Machine" (a name we gave to a player who seemingly plays hands at random.)
With Internet play it is a given that you need to give youself a new name, but the titles to be proud of are those given to you by others. I've been named "Grundy" after the brute who battles Superman, Solomon Grundy. Another name that stuck for me is "Castro," possibly inspired by the untamed beard I sported when I first attended a new game.
What nicknames do you have at the tables? What nicknames have you given others?