Within shapeshifting lore, there are various ways that one might become a werewolf or other shapeshifter. These include:
Natural and Hereditary Shapeshifters – These are folks who are born as shapeshifters. Their entire family might be shapeshifters, or there may be special cases where certain members of a family acquire animal or shapeshifting traits. In the folklore, many types of animals such as the “selkie” (Celtic and Norse seal people) and the kitsune (Japanese fox spirits) have the ability to shift into human form. Sometimes these animals even marry or copulate with humans while in their human form which often results in children who might take on the traits of the shapeshifter parent. There are also tales of deities copulating with humans while the deity is in the form of an animal. This often creates children with shapeshifting abilities or the traits of an animal. In addition to hereditary werewolves, some people are said to be born werewolves because they were born on a certain day such as Christmas Day or the night of a full moon.
Magickal Shapeshifters – These are folks who become werewolves or other shapeshifters through some kind of artificial or magickal means. Generally, these shapeshifters have chosen their path. They may become shapeshifters through spells and rituals, wearing magickal belts or talismans, or by anointing themselves with or ingesting hallucinogenic salves and ointments. These types of shapeshifters include those who practiced witchcraft and werewolfery in the Middle Ages, as well as myths and legends of magicians and sorcerers who decided to take on the guise of various animals through magickal means.
Accidental and Cursed Shapeshifters – These folks didn’t set out to become werewolves or other animals, and they are often traumatized by the experience. They may have been bitten or scratched by a werewolf, inadvertently drunk water downstream from wolves, unknowingly eaten human flesh, or been a victim of any number of other possible mishaps. This category also includes those who are cursed by deities or sorcerers to become wolves or other animals. This includes the Greek werewolf myth where King Lycaon is turned into a wolf by Zeus, the Celtic story of Gwydyon and Gilvaethwy[1], and many others.
Shamanic Shapeshifters – These shapeshifters purposefully take the form of wolves, werewolves, or other animals during shamanic journeying, trance states, and astral travel. Some of these folks may be able to project an image of themselves as a wolf or other animal into the real world through astral projection. Others are able to project their consciousness into the body of a real animal as a form of spirit possession and direct its actions. This is called “wolf riding.”
[1] These two characters were cursed to live for one year as deer, another year as pigs, and a third year as wolves for raping the maiden Goewin. The story also included gender shifting.