Corrosive blood turns your blood into a powerful dissolving agent. This does not cause you any harm, but if a slashing or piercing weapon deals damage to you, a small amount of this potent acidic blood sprays forth, dealing 1d6 points of acid damage +1 point/2 levels (maximum +10) to the weapon in question. If a slashing or piercing natural weapon injures you, the acid affects the creature directly. Either way, the weapon or the creature may reduce the damage by half with a successful Reflex save.