Shapeshifting

Shapeshifting is a common theme in mythology, folklore, and fairy tales. It is also found in epic poems, science fiction literature, fantasy literature, children's literature, Shakespearean comedy, ballet, film, television, comics, and video games. In its broadest sense, shapeshifting occurs when a being (usually human) either (1) has the ability to change its shape or being into that of another person, creature, gender, species, or other entity or (2) finds its shape involuntarily changed by someone else. If the shape change is voluntary, its cause may be an act of will, a magic word or magic words, a potion, or a magic object. If the change is involuntary, its cause may be a curse or spell, a wizard's or magician's or fairy's help, a deity's will, a temporal change such as a full moon or nightfall, love, or death. The transformation may or may not be purposeful.

Read more about Shapeshifting:  Themes in Shapeshifting, Folklore and Mythology