Your skin erupts in swollen, pus-filled bumps that burst open if you are struck. Any creature that strikes you with its body or a handheld weapon deals normal damage, but at the same time the attacker takes 1d6 points of acid damage and must save or be sickened for 1 round. If the attack against you is a critical hit, the attacker must save or be nauseated instead of sickened. This damage can harm a swarm.