Aggro is a term from massively multiplayer games that is, in essence, a measurement of how much monsters hate you. I always had a feeling they were pretty mad, but I didn't know who they were mad at or exactly how much. It's nice to know we can actually determine that kind of thing. 100% cotton heavyweight t-shirt in black. 'Aggro' on the front in white and the Penny Arcade logo on the back.