Werewolves are human beings who transform into a humanoid wolf or a facsimile of a wolf, usually during the night of the full moon. The supernatural phenomenon that causes this transformation is called lycanthropy and is known to occur to various extents throughout the world, most notably in Eastern Europe. Although the origins of the phenomenon are varied, it is known that several practitioners of magic have the ability to shapeshift themselves into animal forms and that they used a variation of this spell as a curse upon those who they considered their enemies, linking the curse to the monthly phases of the moon. In Ancient Greece, Zeus, the ruler of the Olympian Gods, inflicted a werewolf curse on King Lycaon of Arcadia, but the legends behind the phenomenon became most prevalent in Eastern Europe during the Dark Ages. Most variations of the curse are carried on through the descendants of those inflicted with lycanthropy, usually the male heirs of the family line. Women have been known to turn into werewolves but are not as common. It should be known that in regions of the world where wolves are not common, human beings have transformed into such creatures as were-bears, were-leopards, were-jaguars, were-tigers and were-hyenas, but the physical attributes, limitations and weaknesses of these creatures they became remained constant. However, it should be known that several individuals who called themselves werewolves were actually ordinary shape-shifters or practitioners of black magic who gained the power to change form due to pacts with dark gods.

The transformation for true werewolves is a painful metamorphosis mystically triggered by the ascent of the moon during the three nights of the monthly full moon. It was once believed that the light of the moon or its gravitational proximity to the Earth had some factor, but those claims are erroneous. Occurring only at night, the mystical process causes a body-wide process that enhances and augments the human musculature and physiology to perform incredible but not superhuman feats of strength; a typical werewolf can lift (press) over 300 pounds, enough to hurl a full-sized human being several feet. It also causes the brain to secret large amounts of adrenaline in times of fear, rage or stress, which hormonally stimulates the heartbeat rate, raises blood-sugar levels and inhibits sensations of fatigue, heightening normal physical abilities in normal human beings. Werewolves possesses superhuman strength, agility, reflexes, stamina, and senses, all derived from the combination of their adrenaline-powered stamina and their partly wolf-like supernatural form. A typical werewolf can spring from a crouch about 18 feet straight into the air, and their reflexes are about twice as fast as human. Most werewolves can run at a peak speed of 35 miles per hour for up to a half hour before tiring.

The transformation also causes extraordinary hair growth all over the body, transforming victims of lycanthropy into the humanoid equivalent of a typical North American wolf (Canis lupus) or in some rare cases into a nearly exact but larger form of a wolf itself. In these cases, the transformation can be more aggressive and even more painful whereas in shape-shifters its just part of a mystical spell. In full form, werewolf senses of sight, smell, and hearing are as acute as a real wolf. Werewolves can see into the infrared portion of the spectrum, allowing them to see the heat emissions of objects or people in total darkness. They can smell the approach of other organisms within 100 feet and trail the spoor of their quarry across almost any terrain. Werewolf hearing is sensitive enough to detect the sound of a heartbeat in a cave at a distance of 30 feet.

Werewolves have claws and teeth that are particularly sharp and tough, enabling them to rend through a variety of substances, such as fabric, wood, even soft metals and cinderblock. With their consciousness suppressed by the transformation, werewolves are entirely instinctive and cannot think or rationalize, but like dogs and wolves, they have fundamental problem-solving abilities. Driven by an all-consuming urge to kill for food, werewolves are driven to eat any live prey they can capture and mutilate, anything from small animals to human beings. Upon consuming fresh meat, they often retreat into a submissive state during which time they revert to human form.

As a supernatural creature, werewolves are immune to conventional injury including but not limited to penetration wounds, exposure, burning, drowning and suffocation, electrocution, etc. Such phenomena as these can cause physical injury depending on its severity. However, recovery rate is over ten times that of a human being. The adrenaline rate of werewolves prevents them from feeling pain, but upon reverting to human form, they often fall prey to their injuries. The metal silver is necessary to weaken or kill a werewolf, due to its mystical properties of purity, which are anathema to many supernatural creatures, such as werewolves and vampires. If a werewolf is shot or stabbed and mortally wounded by a silver bullet or blade, he or she will die within minutes, returning to human form after death. Contrary to some accounts, werewolves are not immortal and are subject to age and frailty.

The causes of lycanthropy are typically mystical in origin. Several ancient practitioners of magic have claimed to have created the first werewolves with little differences in their spells or curses. Werewolves carry the affliction to death, and in several cases have transferred it through a bite or unhealed wound to another person. In this case, some werewolves extend their curse to others who can then absolve themselves of the curse by killing the werewolf who transferred it, but this is not always the case. Several werewolves have contacted lycanthropy by becoming afflicted by it immediately after slaying a werewolf. It is conceivable this variance is subjective to the origin of the lycanthropy. Known werewolves subject to lycanthropy due to familial curses are Jack Russell, Chris Jennings and possibly Mason Greyback, although the latter is generally suspected to be a mere shape-changer due to his unusual control over his transformations. Known werewolves to have contacted lycanthropy due to contact with other werewolves are Lawrence Talbot, Eric Cord and David Kessler. It should be noted that there are several individuals who have erroneously called themselves werewolves but were actually normal human beings with genetic aberrations, such as teenager Scott Howard.