Rancid Black Tooth

(Stolen from item of same name in the Dark Age of Camelot MMORPG)
The Rancid Black Tooth is a black, +2 short sword. It adds +2 to the wielder's armor class in melee. On a natural 18-20, the target takes 2 additional points of damage for 5 rounds. The effect can stack. It does not give off light.