In Wolf's Clothing [A] by aka "Jake" (32K)
"A manitou overtakes a man by night, not by full moon. But when its blood lust builds to an uncontrollable level, a man changes to a sickening creature. It kills, releasing the savage energy. The man returns to his true self, unaware of what has happened. The cycle begins anew the next day." -- Ish in "Shapes"