Occasionally in the middle of the night a black wolf-looking dog with glowing yellow eyes will come to your house and bark at the front door. If your Sim builds up a good relationship with it, the dog will nibble on your Sim's hand. In a bright orange flash, your Sim will turn into a werewolf. Every morning at 6 your Sim will turn back into a person and at night at 8 your Sim will turn back into a werewolf. To cure the werewolf curse call the pet trainer, or the fortune teller if you have The Sims 2: Nightlife.