attack navel 

n.

A term describing someone who is cool overall, but occasionally can be incredibly frustrating. Usually the frustration is caused by the person beating someone else at a game (Scrabble, for example) or something else competitive. Originated on the GameFAQs.com message boards years ago, and while it has maintained a presence since then, it has gone largely unnoticed.

Damn! In the last four out of six games of Scrabble, that attack navel used all seven of her letters within the first two turns!

attack navel by M.M. April 29, 2005