Werewolfs are a race of people with a congenital disease that causes them to experience periodic temporary metamorphoses into an animalistic state. They are the creation of a very special virus. The werewolf virus is a rare strain of rabies that mutated into a non-fatal form but kept some of the most ferocious side-effects. Although this strain of rabies may not or may kill a person, it does take them over. In normal rabies, the virus tunnels through the nerves directly to the brain, avoiding the immune system. However, this is not the case with the werewolf rabies virus. Werewolfs have the virus in every cell of their body, including the cells of the gonads; which means the werewolf condition is passed onto the children of werewolfs. The werewolf bloodline is complex. It is recessive, not every child gets it. It depends whether the father, mother, or both are werewolfs. Although most werewolfs are born with the condition, there are a few who have contracted it by being bitten by a werewolf. Such a werewolf is known as a "bite-in."
A biochemical malady caused by the werewolf virus is a porphyric condition. There is a slow cyclical build-up of toxins in the werewolf's body that every two or three months reaches a critical level and forces major endocrine system changes that initiate a temporary transformation. During this transformed state, the werewolf exhibits some of the usual symptoms of rabies; such as anxiety, hallucinations, delirium. Those symptoms together with a cerebral dysfunction and an insatiable hunger, induce a frenzy that causes the werewolf to behave like a rabid animal. A swelling of the adrenal glands causes a massive surge of adrenaline that gives them augmented strength and speed. In addition, the body-wide biochemical modifications induce a few physical changes as well. From head to toe, the body experiences a super-acceleration of hair growth in a matter of hours, giving the werewolf a very hirsute appearance. A highly increased metabolic rate allows this rapid hair growth and is also responsible for the increased hunger. Along with the hair growth, the skin tightens, making the nails and teeth appear to grow. The tightening of the skin added with a distortion of the muscles of the face, causes the facial features to change, taking on an animalistic look. In addition, there is an inflammation of the sclera, making the whites of the eyes appear red.
A particular alignment of the body's circadian rhythm causes the transformation to only occur at night and to end at dawn. The legend that werewolves turn during the full moon arose from the fact that that's simply when it's easiest to see them. When the transformed state is over, the only physical change that remains is the excess body hair; it must be shaved off. These episodes of physical transformation will leave a werewolf exhausted and vulnerable. This is where the pack comes in. Werewolfs live in packs in order to protect their own and make sure the secret stays safe. That's how they've kept their existence hidden for so long. When they are at their most dangerous, their fellow pack members take them away to a secluded area so they do not prey on humans during the transformed state.
Throughout history, the werewolves' craving for prey during their transformed state has brought them into conflict with mankind. In the middle ages, the werewolfs thrived in the wild forested regions of Europe. However, when farm land ate into their territory, the troubles began. Cattle meant easy prey, it was too tempting; that's when the war started. In one century, thirty thousand werewolfs were tortured and executed. The few dark survivors retreated into the shadows and that's where they've been ever since. Tortured to edge of extinction in medieval Europe, the survivors eventually saw a chance to start out fresh and they took it in America. Here their kind has once again sought the wilderness free from the scrutiny of neighbors. Again they can live an ordinary life, or at least a life that looks ordinary from the outside. Over the passing of history, werewolfs have learned the hard way that being different is a curse.