Scott McCall, the main protagonist, becomes a werewolf after being bitten by an alpha in Wolf Moon. Derek Hale is a werewolf by birth, his lycanthropy passed down through his family line. Peter Hale is the werewolf responsible for biting Scott and a major antagonist. In later seasons, Liam Dunbar and Hayden Romero become new werewolves after both being bitten by Scott himself.
Afterwards, Lycaon and his sons sought out druids with the hopes that the priests could cure them of their curse. Though this wasn't possible the druids were instead able to teach them to shift back and forth between human and wolf form. Subsequently, the werewolf species was born. Because of this earlier relationship between the older wolves and the druids, an alliance formed between the two people which persisted throughout time. Traditionally, druids served the packs as advisors.
From then on particularly, werewolves came to be vilified as monsters of legend. Marie-Jeanne became the progenitor of the Argent family line of werewolf hunters, whom then became the first organized group of hunters and a history of animosity and vendetta between the prominent clans of hunters and the werewolves occurred up to the present day.
Culture & Temperment
Like everyday humans, werewolves are a social race. They have an instinctive camaraderie and kinship towards their fellows. The majority of the canine shapeshifter community belong to a pack. All members of the international community of the shapeshifters, even the lone wolves, respect this hierarchy. To some werewolves, the triskele symbol represents the three categories of their people: alpha, beta and omega.
"We're stronger in numbers. A pack makes the individual more powerful." - Derek Hale
There is a strong cultural belief among the international werewolf families that their lycanthropy and canine abilities bind them together in a strong sense of familial unity.
"We all know a pack is strongest due to its individual parts. The stronger the individual parts, the greater the whole." - Deucalion, the Demon Wolf
Those who are born werewolves or the more relatively experienced of them have been shown to go out of their way to come to the aid of those who are former humans bitten by an alpha to help them learn control of their abilities and inherent aggression so as not to draw attention to themselves, whether from the general human population and by extension, hunters. This is exemplified by Derek's actions and words towards Scott explaining that the two of them were now brothers. Werewolves also demonstrate immense protective streaks towards those close and dear to them, and alliances between packs when fending off a common enemy also occur. Scott's pack and Satomi's pack immediately formed an solid alliance against a squad of hunters who were out for payment from the deadpool and remain on good terms. In a higher priority example, delegations from the packs lead by Talia Hale, Deucalion, Kali and Ennis all converged together to discuss the threat of the Argent hunter family operating in the region.
It is also not unusual for lone wolves to seek out packs to join for refuge, for help in learning control of their animalistic aggression and blend in with human society more efficiently. In other cases, visitors could offer their aid to packs in need, though the primary reason will mostly be because of this instinctive need for companionship. It is uncommon for a werewolf to live and operate alone by choice but still an occurrence.
Despite this code of loyalty and protection, werewolves are still a predatory species. They are shown to be not just competitive but violent by nature.
In the earlier times, due to the active threat of the hunters, werewolves have sought to survive by loosening their ties to humanity and embracing, and indulging in their animalistic bloodlust to hone their abilities, evolve and become stronger. This survival-of-the-fittest mentality is steadfastly believed in by the more corrupt and depraved of them, like Peter Hale or the Alpha Pack. To evolve, the pack would carry out a rite of passage. The lead alpha would bite a human, then have the new beta progeny participate in a kill alongside the alpha as an initiation into the pack. This ritual was carried out by Peter Hale when he'd bitten Scott McCall so to have Scott "reach (his) full potential" whilst on his murder spree. The twins relayed they learned control of their lycanthropy simply by "giving in and letting go." Likewise, when Scott let his anger take over whilst about to savage an assassin that was about to execute preteen Lori Talbot out of injustice and anger. His violent action triggered a transformation into a more monstrous form but regressed when he regained control of himself and spared the man's life.
Werewolves can also be drawn towards and aroused by the concept of having power. Specifically of having alpha rank, so killing an alpha to usurp his alpha spark is a common crime in the international community of werewolves. More to the point of gaining power, the three senior members of the Alpha Pack, Deucalion, Kali and Ennis eagerly indulged in the concept of wielding supreme power, augmenting their alpha powers by killing all of their pack members then forming a pack of alphas. Conflict and skirmishes between rival packs in the manner of a war between gangs for political reasons and survival also occur. This is displayed by the behavior of Deucalion's Alpha Pack when they took notice of responding to Derek's rise to alpha rank and their feud with the members of the Hale and McCall packs.
"Hide and heal. That's what we're taught to do when the hunters find us. - Cora Hale
The majority of werewolves generally do not get along with hunters of the supernatural as they are a prime target for hunters especially since the bloodbath by the Beast of Gévaudan. Most of them are erstwhile enemies of the hunters. Vendetta is also common occurrence amongst the werewolf population mostly due to the hunters' warning and threats and they will symbolize this with the spiral symbol.
Later this initial transformation will be followed by their finger or toenails lengthening into claws and their teeth lengthening into fangs. This default transformation will appear when a werewolf will defend himself or activate his powers.
As werewolves grow in experience or if they were to undergo an evolution, they can develop the ability to shapeshift further. An alpha is supplemented in this talent due to his or her inherent spark of power, a beta most likely by the strength of his pack. Depending on their power and character, a werewolf's transformation could manifest as either an quadrupedal beast, or an bipedal demon.
A unique transformation is the case of twin siblings. Werewolf twins, whether born or bitten, have the ability to merge their bodies into a single larger and stronger werewolf shape. This is symbolic that identical twins are both halves of the same zygote from birth.
One benefit of this talent is that when one of the twins feels pain, the other will feel the other's pain.
Full Wolf Shift
To be able to shapeshift into this form, a werewolf must find the balance between their humanity and their werewolf nature. This form can also be achieved after evolving. Initially, the only two werewolves known to shapeshift into a full wolf were Talia Hale and her elder daughter Laura, both of whom had alpha status.
In Season 4, Derek Hale, most likely as a result of surviving, learning and moving forward from the multiple trials in his turbulent life, underwent an evolution necessary for this shapeshifting ability.
The evolution manifested first as Derek's werewolf eyes changing back to gold. Thereafter he began to lose all his abilities, his senses, strength, speed, healing, and even shapeshifting over a matter of weeks. He was completely brought down to his human guise. Later on he died after being stabbed by a berserker. Minutes later, Derek revived as a fully transformed wolf, all his powers returned and increased. Then he was able to completely intimidate and overpower both Kate, a werejaguar and her berserker. Derek realized losing his powers and dying were because "(he) was evolving."
Because a werewolf's senses are immensely attuned to his own kind, particularly with those who are of the same Pack, they're able to communicate with their fellow members very effectively and over immense distances.
They're able to use their voices to snap fellow Pack members out of non-responsive states such as a purely animalistic bloodlust or a health-related unconsciousness. In Unleashed, Scott McCall growled Isaac Lahey's name at the latter. Isaac then snapped out of a state of bloodlust. In Required Reading, Liam Dunbar, using the same technique, enthralled Scott out of a psychosomatic-enabled asthma attack.
The most particularly common werewolf voice is the roar of an Alpha, with is used to restrain, or force the shift upon, other lesser canine shifters.
The extension of fangs, is one of the first steps in a shapeshift for a werewolf. The fangs can be used as a werewolf's last resort defense mechanism as in Raving, Derek Hale bites Victoria Argent to disarm her during his faceoff with her when saving Scott's life.
Claws, along with fangs, are one of the first shifts in morphology to take place when a werewolf shapeshifts.
The fingernails thicken and become hooked and pointed. The claws can become detached from the werewolf, as in Lunatic one of Scott's claws became lodged in Jackson's car (though they can apparently grow back in later transformations) and a particular set of claws from Talia Hale were stored in the Triskele urn after her death.
A werewolf's claws are their primary instinctive offensive tools, like how fists are for human beings. Alphas, using their claws, can hinder the healing factor of other beings.
An Alpha's claws can also be used to transform a human into a were-creature with a scratch, similar to the Bite, though it is less effective.
Werewolf claws are also used in the process of mind melding.
The hearing of a supernatural creature is far more acute than that of a human's both in frequency range and distance.
A werecreature will be able to listen to conversations, and pick up sounds several yards away from their position, they can hear through walls, and track movement. Beings seen to possess hearing include the werewolf, the werecoyote and the kanima.
Normally when a newly-turned werecreature discovers this ability, one will feel uncomfortable, just picking up the most random sounds in their vicinity and in some cases be overwhelmed by all the different noises.
Eventually when they learn to control and mask this talent, they can simply hone in and listen to one single sound they'd like. Using their hearing, one will be able to search an area, or a crowd of voices to discern a particular object of their interest. One downside of this concentration is that one will be harmed by a loud sound just close to the individual.
Because they can hear someone's heart, an individual with supernatural hearing will be able to discern when one could be lying because of the jump in said person's heartbeat that bolsters the deception.
Another supernatural with a related sense of enhanced hearing is the banshee, which ''hears'' on a frequency only they can receive.
A supernatural sense of smell seems to be as more keen by an order of magnitude, similar to a dog. Canine shapeshifters can track individuals via their scent, much like a bloodhound, and so they are effective trackers. They can also smell illness.
Their sense of smell can be so refined they are able to detect emotions - anger or fear. They do this by picking up chemosignals - chemical signals that communicate emotion, which an individual can give off via their scent, allowing them to identify the hormonal changes that person exhibits, or has exhibited at specific locations in the past.
There are both internal and external changes to the eyes of a supernatural creature. Initially, the eyes will glow in response to emotion. Supernaturals will often identify themselves by flashing their eye color.
A supernatural creature with enhanced vision will more acute than a human's, and in more ways than one, including binocular vision or infrared. Said beings with a supernatural eyesight will possess glowing eyes that is reflective of their species.
Also, supernatural eyesight will reflect the light like eyeshine. Because of this, photographing, or filming such a person with an enhanced eyesight will be rather difficult, unless the being knows how to mask their vision.
Shapeshifters, or were-creatures such as canines, the werewolf, or the feline werejaguar will have night vision like most predators, being able to see well in low light as well as binocular vision. While provoked into a state of aggression, or in a state of bloodlust, a were-creature's vision will be internally depicted as red.
It's an ancient ritual used mostly by alphas, since it's a skill that requires quite a bit of practice. One slip, and you could paralyze someone. Or kill them. - Peter Hale
Werewolves can meld their minds with those of others by inserting their claws into the recipients at the base of their skull.
Mind melding is used exclusively by the most experienced of shapeshifters, or alphas, as it is a dangerous act to perform. If not performed properly, the ritual could kill the recipient, paralyze them, or render them catatonic. If the process, the bond was broken by an outsider, it could kill both the user and recipient.
In 1x10 - Co-Captain, Peter Hale shared his memories of the Hale Fire and his coma with his werewolf progeny Scott McCall. Later in 3x02 - Chaos Rising he was able to partially uncover some of Isaac Lahey's memories that had been wiped by the Alpha Pack.
In 3x22 - De-Void, Scott McCall, with Peter's instruction, performed this ritual with his claws in both Stiles and Lydia, and so he and Lydia were able to both enter Stiles' subconscious, with the intention of splitting Stiles from the Nogitsune. In 5x08 - Ouroboros, Scott tapped into Corey's memories in an attempt to find the Dread Doctors' lair.
A technique a werewolf can also learn is a mastery over their physical bodies. This capability allows them to completely blend in with human society in every way.
In Orphaned, Derek outlines this mastery in the sense that werewolves can actually inhibit their own scent so they can avoid detection.
In The Girl Who Knew Too Much, Scott tries to locate Lydia with his internal werewolf vision, yet externally his eyes looked completely normal, supposedly because he'd had the necessary control to mask his vision.
It is commonly believed by these shapeshifters, particularly werewolves, that the full moon bestows them their power that their abilities are at their peak, but at the cost of heightened aggression.
"There's a price you pay for this kind of power. You get the ability to heal, but tonight, you're gonna want to kill anything you can find." - Derek Hale
Born werewolves can learn to control their animal instincts and aggression on the full moon as it's part of their nature. Recently bitten wolves however, have a harder time controlling their transformations and bloodlust during their early full moons, making it a particularly dangerous time to be around people. With time, training, practice and concentration on an anchor, the new shapeshifter can learn to control himself.
Full moons are also a source of power for werewolves. On the full moon in March, the Worm Moon, Peter Hale, in a ritual conducted by Lydia, came back to life.
During the lunar eclipse, werewolves completely lose all their supernatural talents and abilities, simply rendering them to their human guise.
Fueled by anger, werewolves can enter a violent, animalistic state of bloodlust. They are unable to control their desire to kill and seem largely beyond rational thought. Scott is unable to remember anything from the fugue state.
A werewolf's vision is shown to be red to indicate this state, and their field of vision fairly narrow and concentrated on movement.
Real world mythology
In actual mythology, werewolves are susceptible to silver.