The Ligahoo or loup-garou is the shapeshifter of Trinidad and Tobago's folklore. In his centuries long life he became successively a stag, a wild boar, a hawk and finally a salmon prior to being eaten and (as in the Wooing of Étaín) reborn as a human. He finally turned into a burning coal and was thrown into a well, whereupon he reappeared in his human form. Examples of shapeshifting in classical literature include many examples in Ovid's Metamorphoses, Circe's transforming of Odysseus' men to pigs in Homer's The Odyssey, and Apuleius's Lucius becoming a donkey in The Golden Ass.
When a form is taken on involuntarily, the thematic effect can be one of confinement and restraint; the person is bound to the new form. Berserkers were held to change into wolves and bears in order to fight more effectively.
Svipdagr angered Odin, who turned him into a dragon. Naturally, its hard to pin down a Shapeshifter’s appearance. In many cases, imposed forms are punitive in nature. His brother, Ótr, enjoyed spending time as an otter, which led to his accidental slaying by Loki.
Again, these characters are almost always up to no good. Despite his monstrous appearance, his lover, the goddess Freyja, refused to leave his side. The Volsunga saga contains many shapeshifting characters. This eventually leads to a form in which the character (or characters) can reveal the truth to someone able to stop the villain.
Shamans believed that, by entering a ritual state, they could send their spirit out of their body, in the shape of an animal, to roam around the world, while warriors known as “beserkers” believed that they could take the shape of a wolf or bear in battle by wearing the animal’s skin. Therianthropyis the more general term for … Alberich, his counterpart in Richard Wagner's Der Ring des Nibelungen, using the Tarnhelm, takes on many forms, including a giant serpent and a toad, in a failed attempt to impress or intimidate Loki and Odin/Wotan. Using their gift with magic, these characters could take on almost any form they wanted, and they frequently placed curses on heroes and princesses as well, trapping them in an ugly form until the curse was broken. Richard M. Dorson, "Foreword", p xxiv, Georgias A. Megas, Scottish Highlanders and Native Americans: indigenous education in the eighteenth-century Atlantic world Margaret Szasz 2007 University of Oklahoma Press. In the Lokasenna, Odin and Loki taunt each other with having taken the form of females and nursing offspring to which they had given birth.
Deucalion and Pyrrha repopulated the world after a flood by throwing stones behind them; they were transformed into people.
Gilfaethwy committed rape with help from his brother Gwydion. Like the Greeks, the Norse people attributed the power of shapeshifting to their gods. , Sometimes the bridegroom removes his animal skin for the wedding night, whereupon it can be burned. The prefix "were-," coming from the Old English word for "man" (masculine rather than generic), is also used to designate shapeshifters; despite its root, it is used to indicate female shapeshifters as well. There are African folk tales of murder victims avenging themselves in the form of crocodiles that can shapeshift into human form.. Cadmus is also often known to have transformed into a dragon or serpent towards the end of his life. While the skinwalkers certainly aren’t friendly to humans, they aren’t particularly dangerous either. In trickster folklore, shapeshifting is the characters’ only magical ability, but they combines so much cunning with their shapeshifting abilities that they are still a powerful force. A similar effect is found in Child ballad 34, Kemp Owyne, where the hero can transform a dragon back into a maiden by kissing her three times. Therianthropy is the more general term for human-animal shifts, but it is rarely used in that capacity.  Artemis transformed Actaeon into a stag for spying on her bathing, and he was later devoured by his own hunting dogs.
If a female at midnight stretches the membrane which envelopes the foal when it is brought forth, between four sticks and creeps through it, naked, she will bear children without pain; but all the boys will be shamans, and all the girls Maras. Likewise, Odin was fond of transforming into the shape of an eagle.
Fafnir was originally a dwarf, a giant or even a human, depending on the exact myth, but in all variants he transformed into a dragon—a symbol of greed—while guarding his ill-gotten hoard. Nereus told Heracles where to find the Apples of the Hesperides for the same reason. Atalanta and Hippomenes were turned into lions after making love in one of Zeus' temples. In one tale, Demeter transformed herself into a mare to escape Poseidon, but Poseidon counter-transformed himself into a stallion to pursue her, and succeeded in the rape. Fafnir was originally a dwarf, a giant or even a human, depending on the exact myth, but in all variants he transformed into a dragon—a symbol of greed—while guarding his ill-gotten hoard. The name of the Nahuel Huapi Lake in Argentina derives from the toponym of its major island in Mapudungun (Mapuche language): "Island of the Jaguar (or Puma)", from nahuel, "puma (or jaguar)", and huapí, "island".  In Tatterhood, Tatterhood is transformed by her asking her bridegroom why he didn't ask her why she rode a goat, why she carried a spoon, and why she was so ugly, and when he asked her, denying it and therefore transforming her goat into a horse, her spoon into a fan, and herself into a beauty. Shapeshifting to the form of a wolf is specifically known as lycanthropy, and such creatures who undergo such change are called lycanthropes. In fairy tales, such transformations are usually temporary, but they commonly appear as the resolution of myths (as in many of the Metamorphoses) or produce origin myths. She later bore the egg in which Helen of Troy was found.
The Titan Metis, the first wife of Zeus and the mother of the goddess Athena, was believed to be able to change her appearance into anything she wanted. Often, this sort of transformation was used as a punishment; the goddess Athena transformed a mortal, Arachne, into a spider because she had challenged Athena’s skill at weaving, and Zeus transformed another mortal, Lycaon, into a wolf because he tried to trick Zeus into eating human flesh. Athena sprang from her father's head, fully grown, and in battle armor.
https://mythology.wikia.org/wiki/Shapeshifting?oldid=110583. In one story, she was so proud, that her husband, Zeus, tricked her into changing into a fly.
 In the Greek tale of Scylla, Scylla's father Nisus turns into an eagle after death and drowns her daughter for betraying her father.  This obstacle chase is literally found worldwide, in many variants in every region. Also, talismans (called "anting-anting" or "birtud" in the local dialect), can give their owners the ability to shapeshift. Beauty and the Beast has been interpreted as a young woman's coming-of-age, in which she changes from being repulsed by sexual activity and regarding a husband therefore bestial, to a mature woman who can marry. Even Shapeshifting, the trait which unifies them, is sometimes more of a curse than an actual magical ability. This makes an example for a voluntary shapeshifting becoming an imprisoning metamorphosis. One motif is a shape change in order to obtain abilities in the new form. The magic happens due to a potion given to her by an old witch.  Another such creature is the Scottish selkie, which needs its sealskin to regain its form.
The most dramatic example of shapeshifting in Irish myth is that of Tuan mac Cairill, the only survivor of Partholón's settlement of Ireland. Sometimes metamorphoses transformed objects into humans. The most common use of this motif, however, is in tales where a man steals the article and forces the shapeshifter, trapped in human form, to become his bride.
Siggeir's mother changed into a wolf to help torture his defeated brothers-in-law with slow and ignominious deaths. Shapeshifting to the form of a wolf is specifically known as lycanthropy, and such creatures who undergo such change are called lycanthropes. Other terms for shapeshifters include metamorph, the Navajo skin-walker, mimic, and therianthrope. Math fab Mathonwy and Gwydion transform flowers into a woman named Blodeuwedd, and when she betrays her husband Lleu Llaw Gyffes, who is transformed into an eagle, they transform her again, into an owl.