You know i dont think there are many games which have werewolves in them, a pity since they are very agressive creatures.
Just for reference, in Dungeons & Dragons, you can create werewolf characters, but you have to sacrifice 5 character levels due to their extreme bonuses. This means you have to start the game along side level 6 characters as a level 1 werewolf. Given that the basic game only has 20 levels, this is quite a big sacrifice.
Perhaps there could be a quest that causes you to become a werewolf, but at the expense of 50 attribute points (10 levels worth). When you transform, however, your stats increase greatly.