Leeroy Jenkins
The video which made Leeroy so famous shows him and his friends, doing a friendly activity known as a Raid in World of Warcraft, but this activity is hard to do, so the leader of the group that Leeroy is with has to explain what to do. But Leeroy is not around for the explanation, preparing some chicken, and when he comes back, he ends up running in the area, shouting his own name as he goes, which begins the activity, and ruining the plan which his friends made. This causes everyone to panic, and no-one knows what to do, and so, everyone dies. Everyone blames Leeroy for this, and he says "At least I got chicken."