It's Usopp, one of the main characters from One Piece.
I got super into One Piece a few months back, and usually have an avatar to reflect whatever I'm infatuated with at the moment, so generally changes every four or five months.
I might stick with this one for some time though. On top of Usopp being my favourite character in the series, he's kind of like a summary of traits my favourite characters tend to have. He's the main source of comic relief, generally makes everything more light-hearted, but is fully aware of how abundantly useless he is compared to everyone else, which I can relate to.
I also think it looks kinda cool. That helps.