In Bloodmoon quest, at the very end, you will be entered in Hircine's hunt. If you are a werewolf, change back into human, nomatter how long it takes. Once human, you must get to the second arera of the maze. Find Heart-Fang (leader of the Skall). Hew will give you the option to join forces. Refuse and kill him. He will not only reveal he's a werewolf, but after you kill him, you recieve Hircine's Ring. When worn, you become a werewolf. You get it from him even if you're a werewolf.