In the world of gaming, particularly massive online battle arenas (MOBAs), an experienced player who plays on a low-level account. This type of person is typically an egocentric and unsympathetic piece of human filth who ruins the gaming experience of actually inexperienced players by making them completely unable to play the game.
Being a smurf stems from deep-seated insecurity about one's value in life, in response to which the smurf seeks to confirm to himself his self-worth by proving that he is better than someone at something.
Gamer's friend: Dude, you're getting destroyed.
Gamer: Yeah, this fucking bag-o-dicks smurf gets off on ruining other people's games.