shapeshifter

noun2

1. •
   A person or creature capable of changing their appearance or form at will.

   • The shapeshifter Lisa Bowalk, unable to shed the guise of a black panther, had gone onto the plain as a prisoner but was not now to be found among the dead above or the Captured down below. — 2000
2. •
   (figurative) A person who is inconsistent and elusive.

   • She was an alcoholic, very chageable, very deceptive. A shapeshifter. You never knew where you stood with her, […] — 2023