Shapechanger

Ancient archetype that may be understood in at least three different ways.

1. Any character can wear a different archetype hat at different stages of the story, and when this happens, the character might be said to change shape.
2. In a sense, the False Ally is a shapechanger, though a real Shapechanger doesn’t merely reveal her or his true motivation at some point, but actually alters her or his essence once or several times in the story.
3. Another way of defining the Shapechanger archetype is more literal; for example, all the stories in Ovid’s Metamorphoses feature Shapechangers.

Famous Shapechanger: Proteus. Modern example: most Marvel superheroes. See Archetypes.