Fanmuffin
A combination of a Fangirl (or fanboy) and a twatmuffin. Generally close minded overzealous fans who - upon realizing they can't win an argument - result to insults and general asshattery.
Guy one: Did you see that guy's rant on how 'awesome' Sephiroth is?
Guy two: Yeah he's a complete fanmuffin.
Guy two: Yeah he's a complete fanmuffin.