Transformation: When the moon is full, werewolves change from human form to a human-wolf hybrid. This form is taller and stronger than the human form.
Creating more werewolves: Werewolves can create more of their kind, either by biting a human or by sexual intercourse. Lycanthropic pregnancy is only three months. Werewolves prefer to mate with each other, though some have formed relationships with humans.
Strength: In wolf form, a werewolf can toss around a Volkswagen Beetle, or knock an armored car on its side. In human form, a werewolf is about 20% stronger than the strongest person of their gender in the world (although they probably won't draw attention to themselves by showing off in the gym).
Speed: In wolf form, a werewolf can run up to 40 mph. In human form, a werewolf could run a mile in under 4 minutes (again, they probably wouldn't draw attention this way).
Stamina: In wolf form, a werewolf doesn't get tired until it has eaten its fill; then, after tending to bodily waste, it will sleep until morning. In human form, a werewolf can do hard, physical labor for hours, or run the equivalent of a marathon without breathing heavily or breaking a sweat.
Agility: In wolf form, a werewolf rarely, if ever, loses footing. In human form, a werewolf could be an amazing gymnast.
Vision: In wolf form, a werewolf can see perfectly in the dark. In human form, a werewolf could be a sniper in the military.
Hearing: In wolf form, a werewolf can hear the heartbeat of its prey. In human form, a werewolf can hear a whispered conversation from 100 feet away in a crowded room.
Smell: In wolf form, a werewolf can track prey for miles with barely a whiff of scent. In human form, a werewolf can tell from one sniff if the cleaning staff have been less than diligent.
Healing: In wolf form, a werewolf can heal almost instantaneously. In human form, a werewolf can heal seven times faster than a normal human. The metamorphosis can heal broken bones immediately. Werewolves are immune to all diseases, though they can transmit them for a period of 24 hours after exposure.