This should answer your question

There are questions and answers scattered all over this board.. best to try to put em all in the same place.
2.) Once a sim is a werewolf, is he or she always a werewolf or does he or she turn at certain times?
a.) The cursed sim will go through the transformation every night between the hours of 20:00 and 6:00. At 6:00 the sim will transform back, sometimes. Once in awhile there's a glitch and the transformation back doesn't happen. Your sim won't be able to savage, howl, or call other wolves but the sim will still look like the werewolf. This seems to be merely a bug, it eventually fixes it self the next morning..