Gaming Vampire

Someone who is awake all night gaming, then sleeps in the morning or later that day. In competitive games the average night time player is usually more dedicated and of a higher skill level than the average during the day, making ranked play at night a more risky and difficult prospect.

"Jim: Yea, we had like 10 ranked games, but we played in the middle of the night when all the vampires were out so it was pretty rough going.
Jimbo: Yea man, gaming vampires can be pretty sweaty."