Almost every culture around the world has some type of shapeshifting myth, and almost every commonly found animal  probably have a shapeshifting myth attached to it. Usually, the animal involved in the transformation is most likely indigenous to or prevalent in the area from which the story derives.

Popular shapeshifting creatures in myths and legends are werewolves and vampires (mostly of European, Canadian, and Native American/early American origin), the kitsune or were-foxes of Japan, and the gods and goddesses of numerous mythologies, such as Loki from Norse mythology or Proteus from Greek mythology. It was also common for deities to transform mortals into animals and plants. Some conspiracy theories even claim that alien reptoids are capable of shapeshifting into humans and are living among us.

Therianthropy is the more general term for human-animal shifts, but it is rarely used in that capacity. Other terms for shapeshifters include metamorph, skin-walker, mimic, animal folk, animal people, animen, weres or therianthropes. The prefix "were," coming from an Old English word meaning "man", is also used to designate shapeshifters. Examples are "werewolf," "weretiger," etc. Although shapeshifting to the form of a wolf is specifically known as lycanthropy, it is commonly used to describe any human-animal transformations and the creatures who undergo them.

Also, it is worthy to note that while the popular idea of a shapeshifter is of a human being who turns into something else, there are numerous myths about animals that can transform themselves as well. This is already true in the real world.

Some animals, particularly octopuses, are able to change their body shape and color to mimic other creatures and objects, for camouflage or to hide in narrow spaces. The Mimic Octopus is noted for its ability to impersonate sea snakes, widely different fish species, and rock formations.

Insects often undergo metamorphosis, in a transformation between their larval and adult stages. While fictional metamorphoses are almost always permanent, these changes are always so.