How do I become a werewolf in the sims three supernatural game?

You can buy or make a poison, or make out with a werewolf and have a werewolf-child (however this is harder than the poison). Or you can chose to 'change the village' or something like that (I don't exactly know because I play it in dutch, but you have to click on 'options' and you will see it) make an extra 'family' with the werewolf you want and combine it with your family. You can also use the cheat 'testingcheatsenabled true', press ctrl and you will see the option to change your sim.
I gave a lot of possibilities so you can pick the one you want...
Have fun!
(sorry for the bad english)

Well in CAS you can select what type of specie you want your person to be, you can choose fairy, witch, vampire, ghost, human, genie(Only if you have showtime) or in your case a werwolf. You can also get a witch to whip up a potion or you can go to the alchemy store and see if they have any potions to turn you into a werewolf. For me my sims are werewolves but at the lunar cycle or when I force them to become a werewolf they don't transform for some reason they don't allow them selves to transform help plez

I`m wanting to know the same thing

You could click control, shift, and c at the same time and put testingcheatsenabled true.Then you shift and click on the sim you want to be a werewolf, and there will be an edit the sim option. There in the edit the sim option you could change your sim into a with, fairy, werewolf, etc. Hope this helped!