In Greek mythology, what is the name of the shape-shifting sea god who can assume the form of any animal or human?

In J.R.R. Tolkien's The Lord of the Rings, what is the name of the shapeshifting creature that can take the form of a wolf?

In the Harry Potter series, what is the name of the magical creature that can transform itself into other people?

In Stephen King's novel The Stand, what is the name of the shapeshifting creature that can assume the form of anyone it kills?

In the television series Supernatural, what is the name of the shapeshifting creature that can take the form of any human it sees?

In the video game The Witcher 3: Wild Hunt, what is the name of the shapeshifting creature that can take the form of a wolf, a bear, or a cat?

In the novel The Shape-Changer's Wife by Thomas Glave, what is the name of the shapeshifting creature that can take the form of any animal?

In the television series Grimm, what is the name of the shapeshifting creature that can take the form of any animal or human?

In the novel The Changeling by Victor LaValle, what is the name of the shapeshifting creature that can take the form of a child?

In the film The Thing, what is the name of the shapeshifting creature that can assimilate and imitate other living organisms?

In the novel The Sparrow by Mary Doria Russell, what is the name of the shapeshifting creature that can take the form of any human it sees?

In the television series The X-Files, what is the name of the shapeshifting creature that can take the form of any human or animal?

In the novel The Prestige by Christopher Priest, what is the name of the shapeshifting creature that can take the form of any human?

In the film Annihilation, what is the name of the shapeshifting creature that can take the form of any living organism?

In the novel The Shape-Shifter by Tony Hillerman, what is the name of the shapeshifting creature that can take the form of any animal?