A werewolf, also known as a lycanthrope, is a human being who, upon the complete rising of the full moon, becomes an uncontrollable, fearsome and deadly wolf. This condition is caused by infection with lycanthropy, also known as werewolfry. Werewolves appear in the form of a wolf but, there are distinctions between them and regular wolves.

A mixture of powdered silver and dittany applied to a fresh bite will seal the wound and allow the victim to live on as a werewolf, although tragic tales are told of knowing victims begging for death rather than becoming werewolves. The Wolfsbane Potion, invented by Damocles, allows the werewolf to keep their human mind during transformation.

A werewolf cannot choose whether to transform and will no longer remember who they are and would kill even their best friend given the opportunity once transformed. Despite this, they are able to recall everything they have experienced throughout their transformation upon reverting to their human form.

Eye colour
Varies
Skin colour
Varies
Hair colour
Varies
Related to

Wolf
Human

Native to
World-wide
Mortality
Mortal
Affiliation

Lord Voldemort
Order of the Phoenix
Werewolf army

Ministry of Magic Classification

Being
Beast

XXXXX
Status
Extant

Lycanthropy is a magical illness known to be spread by contact between saliva and blood; thus, when a transformed werewolf bites a human, the bitten will become a werewolf themselves. Most Muggles, however, will die from the extent of their injuries in the instance of a werewolf attack as noted by Professor Marlowe Forfang, though some do survive to become werewolves themselves. If a werewolf is in human form and bites the victim, they will merely gain lupine tendencies such as a fondness for rare meat. Any bite or scratch obtained from a werewolf, whether in human or animal form, will leave permanent scars. However, the fresh wound can be sealed with a mixture of powdered silver and dittany.

The only known human born to at least one werewolf parent (untransformed at the time of conception) was Teddy Lupin, son of werewolf Remus and human metamorphmagus Nymphadora Tonks. Teddy did not inherit his father's condition, however it is unknown if it definitively cannot be passed on in this manner or if Teddy did not inherit the condition from pure chance as other than Teddy, there was no documentation of a werewolf having a child in human form. In Teddy's case it was his father who was a werewolf, not his mother, therefore it is unknown if a pregnant female werewolf's transformations would affect the ability to carry the pregnancy to term.

Greyback's appearance when in human form has a wolf like quality

If two werewolves mate at the full moon, in their animal forms, something very strange happens. The result of their mating, which has only ever occurred twice throughout history, has been a pack of wolf cubs — actual wolf cubs — who grow to become very beautiful wolves and can only be distinguished from true wolves by their near-human intelligence.

Thus, rumours of werewolves living in the Forbidden Forest in the grounds of Hogwarts Castle are actually about a pack of lupine werewolf offspring that was released into the woods with the kind permission of Albus Dumbledore, Headmaster of the School, and has lived there ever since. Teachers have never tried to dispel these rumours because they felt that keeping students out of the forest was highly desirable.
Treatments

Unfortunately, there is currently no cure for lycanthropy. However, some of the worst effects can be mitigated by consuming Wolfsbane Potion, which allows a werewolf to retain his or her human mind while transformed, thus freeing him or her from the worry of harming other humans or themselves. It is a very difficult potion to make, with many complicated ingredients. According to Remus Lupin, it tastes disgusting, but sugar makes it useless. The high cost of the ingredients makes it virtually impossible for werewolves to brew the potion for themselves, as most are reduced to poverty and cannot taste the potion without revealing their statuses. Because werewolves only pose a danger to humans, companionship with animals whilst transformed has been known to make the experience more bearable as the werewolf has no-one to harm and will be less willing to harm themselves.

According to Gilderoy Lockhart, the Homorphus Charm can force a werewolf back into human shape. However, due to Lockhart's reputation as a liar, and the many falsehoods he told to inflate his popularity, his information is highly suspect — as is the very existence of a Homorphus Charm in the first place. However, as many of Lockhart's claims are also based on the accounts of more trustworthy wizards (accomplishments he would claim for himself, following the disposal of the originating witch or wizard), there is a chance that the charm does, in fact, exist.

In the 1980s Cecil Lee, a wizard working for the Ministry of Magic's Werewolf Capture Unit, told Jacob's Sibling that he had used the Homorphus Charm during his job. However, for him, the charm "only" forced the werewolf to temporarily revert to human form rather than permanently curing them as Lockhart claimed. Though as Lee was a fan of Lockheart's, he believed that this was due to his own inability to perfectly cast the charm.

Contrary to what the Muggle world believes, werewolves are not affected by silver, except in that it can be used in the mixture of powdered silver and dittany to prevent death and merely closes their wounds to prevent bleeding in a severe werewolf attack. There may certainly be several other ways and solutions to prevent and heal werewolf injuries, as Quirinus Quirrell taught about the topic in first year Defence against the Dark Arts class. None of them, of course, could completely cure an afflicted person once they are bitten, but can merely prevent and close the physical wounds on the skin.
Description
Monthly transformations

The monthly transformation of a werewolf is extremely painful if untreated and is usually preceded and succeeded by a few days of pallor and ill health. The werewolf may display irritation towards friends. While in his or her wolfish form, the werewolf loses entirely its human sense of right or wrong. However, it is incorrect to state (as some authorities have, notably Professor Emerett Picardy in his book Lupine Lawlessness: Why Lycanthropes Don’t Deserve to Live) that they suffer from a permanent loss of moral sense.

While human, the werewolf may be as good or kind as the next person. Alternatively, they may be dangerous even while human, as in the case of Fenrir Greyback, who attempts to bite and maim as a man and keeps his nails sharpened into claw-like points for the purpose. Though werewolves usually only infect their victims through biting, they sometimes take it too far and kill their victims.

Without any humans nearby to attack, or other animals to occupy it, the werewolf will attack itself out of frustration. This leaves many werewolves such as Remus Lupin with self-inflicted scars and premature ageing from the difficult transformations.
Appearance and traits

Werewolves can be easily distinguished from regular wolves by their shorter snout, more human-like eyes, the tufted tail, and their mindless hunting of humans whilst in wolf form. At all other times, they appear as normal humans, although they will age prematurely, and will gain a pallor as the moon approaches and then wanes.

The real difference between a wolf and a werewolf is in behaviour. Genuine wolves are not very aggressive, and the vast number of folk tales representing them as mindless predators are now believed by wizarding authorities to refer to werewolves, not true wolves. A wolf is unlikely to attack a human except under exceptional circumstances. The werewolf, however, targets humans almost exclusively and poses very little danger to any other creature.

At one point, the Werewolf Registry and Werewolf Capture Unit were both in the Beast Division, while at the same time the office for Werewolf Support Services was in the Being Division. These regulations and services were ultimately a failure, as no one would be prepared to walk into the Ministry to admit themselves as werewolves, and thus none took the prescribed responsibilities of the Werewolf Code of Conduct.

The Werewolf Code of Conduct of 1637 was meant to give Werewolves a framework for coexisting safely and legally within the wizarding world. Werewolves were required to sign a copy of the Code and promise to refrain from attacking and biting non-werewolves. They were also supposed to lock themselves away during their wolf transformation periods. As no werewolf was willing to sign it, the Ministry had huge difficulty in hunting down culprits of these attacks, such that Fenrir Greyback was able to act innocent in regard to him murdering two Muggle children.

Werewolves are classified as a XXXXX creature in their transformed state. Dolores Umbridge herself incorrectly referred to werewolves as half-breeds, and has drafted an anti-werewolf legislation that made it almost impossible for werewolves to find a job.