Werewolf

Werewolves are able to change from human to wolf forms at will, though frequent transformations will leave the subject exhausted for a time.
A pure-blooded wolf is one that was born as a werewolf. Pure-bloods can turn humans into werewolves by biting them, though this change is quite harsh on the victim as the first transformations are quite painful (especially growing a tail).
A bitten wolf cannot turn others nor can they transform at will. They automatically transform into wolves during the full moon and can only change back the following morning. 
As per their nature as wolves, Werewolves possesses excellent smell and hearing. These abilities are even stronger in their wolf form. They are also adept at reading body language.

Basic Information

Anatomy

In their human forms, werewolves have slightly pointed ears, pronounced canine teeth, and furry tails (which may be hidden beneath their clothing).
In their wolf forms, werewolves are large wolves with fur matching the color of their human hair.
In their hybrid forms, werewolves remain largely bipedal with thick fur covering their bodies, tow and finger nails lengthening into claws, and canine features to their face.

Biological Traits

Werewolves cannot perform magic like other races. 
However, they do possess accelerated healing for wounds inflicted by non-silver, non-magical weapons.

Genetics and Reproduction

Outside of basic procreation, werewolves can turn other beings by biting them. This is rare, though, as doing so can only be done by mature, pure-blooded wolves. The change is also frowned upon on by most packs as it caused the victim considerable pain during initial transformations.
The efficacy of pure-blooded Wolf's bite varies greatly depending on the phase of the moon. During a full moon, a bite will successfully turn its victim about 75% of the time. Outside of a full moon, however, the odds of transmitting Lycanthropy drop off considerably with a bite occurring during a new moon having less than a 5% chance of transmission.

Ecology and Habitats

Werewolves live in packs in forested areas. They have been known to enter human villages and towns to trade, though are careful with often concealing signs of their species given that many humans are distrusting of werewolves.

Dietary Needs and Habits

Werewolves are carnivores, hunting their meals (and using leftover materials like furs as supplies and trade). They also eat herbs and plants.

Biological Cycle

How much a werewolf leans towards their human or animal sides can be greatly influenced by the phases of the moon, with their animal instincts being strongest during a full moon and weakest at new moon. Whichever form they are in, wolves retain their memories, personality, and intelligence, though these can be addled by strong animal instincts.

Additional Information

Social Structure

Werewolves typically live in small, semi-nomadic communities referred to as packs.

Average Intelligence

Werewolves maintain most of their intelligence and personality when transformed into wolves. However, there is brief period of disorientation during/following the initial transformation as the senses shift from those of a human to a wolf's. This experience tends to be minimal for pure-blooded wolves, but can be severe for bitten wolves as the transformation itself is much less natural for them.

Perception and Sensory Capabilities

Strong hearing and smell
Strong body language skills
(D&D terms: Werewolves have advantage on Wisdom/Perception rolls that deal with hearing and smell and Wisdom/Insight rolls when haivng line of sight on whoever they are talking to)

Civilization and Culture

Major Language Groups and Dialects

Wolves, while able to communicate verbally when in their human forms, don't have a unique language so much as a keen sense for physical/body language given how much time they spend as animals. This tends to mean that they're more accustomed to simpler communication as opposed to complex dialogue.

Common Dress Code

Werewolves tend to wear clothing woven from the fur they shed when they transform from wolf to human. These garments transform with them when they change back to their wolf or hybrid forms, blending in with their fur.  The one caviate is that if they wear another wolf's clothing when they transform, their fur will reflect the different color of the garments over the areas that were covered in their human form.

Common Taboos

For most packs, the biting and transmitting of Lycanthropy is very much frowned upon on. One of the main reasons for this is concerns over relations with humans.

Interspecies Relations and Assumptions

Human: Humans and Werewolves tend to treat each other with caution, so much so that wolves tends to hide their features when trading to avoid issues.

Related Organizations

• The Hound's Fang

Related Myths

• Tirmac, The Great White Wolf