Shapeshifting[Footnote 1] is the act or power of metamorphosis, of transforming physical shape or form.
The transformation can involve physical changes from a simple alteration of appearance to a full transformation into another bodily form.
Therianthropy is the act or power of shapeshifting into an animal or animal-like form. A person shapeshifting thus is called a therianthrope or theriomorph. The term is derived from Greek theríon (θηρίον, "animal") and anthrōpos (άνθρωπος, "human").
Most well known are the lupine theriomorphs: werewolves, hexenwolves, loup-garous, and lycanthropes. Other theriomorphs mentioned are werebears, weretigers, and werebuffaloes; the last were a form of therianthropy that was archived by some Native American shamans. Most common are predator animals, with wolves again being one of the most common.
Transforming somebody else into an animal is likely to destroy the person's personality and mind completely and irretrievably, leaving nothing but the animal in the end. Persons with strong minds and wills may manage to retain their human selves for a longer time, up to several years. Because of the harmful effects the transformation of unwilling persons is forbidden by the Second Law of Magic of the White Council.
Wizards are also able to shapeshift. The only known shapeshifter is Senior Council member Joseph Listens-to-Wind. He is able to shift in various forms in the blink of an eye. His forms include a bear. He also doesn't have to remove his clothes when shapeshifting.