How would you make a Werewolf gamepack unique ?

I'd like it if they were normally a sim but became a werewolf at night. There could be other times though like maybe they could chose to transform or if under extreme stress like low needs or explosive anger they would also become one. Not sure what they could do though as they are pretty against killing in this game. The fight animations have gotten good though... sparring and even the magical animations during dueling so maybe they could bat someone around pretty good... Maybe if they bite a sim would have to find an antidote within a certain time frame to avoid becoming one.
Otherwise I'm not up on current werewolf stuff.