One who seems to fluke an unbeatable poker hand from two terrible starting cards regardless of the quality of his/her apponents hand.
You are sitting on pocket aces and go all in. He/she has seven-two off suit and calls for the hell of it. They somehow manage to spawn an unbeatable full house, trips or quads, usually on fourth street and the river. They then make out it was skill and they knew it would happen all along. He/she has played a Lucky Wilson.