Someone who comments on a video, blog post, or another piece of internet media before anyone else with the word "First!!!" or some variation of the phrase. Most of the time, the person is very excited for this pointless achievement and is looked down on by the population of the internet with brain cells.
Collegehumor has posted a new video.
Person One: "FIRST! F@$K YEAH!"
Person Two: "Congrats, you win the Dumb Ass Award Firstfag."