shapeshift

Probably a back-formation from shapeshifter.

shapeshift (third-person singular simple present shapeshifts, present participle shapeshifting, simple past and past participle shapeshifted)

1. (fantasy, mythology, intransitive) To change one's shape or form (into another) through often magical means, normally applied only to living beings.
2. (figuratively, intransitive) To undergo a noticeable change (in character for example), to metamorphosize.
   • 2019, Adam Turner-Heffer, Chelsea Wolfe: Birth of Violence review, The Skinny, September 2019, page 57:

     While Chelsea Wolfe has often shapeshifted in terms of how she presents her music, one thing remains constant: her big mood.

• phaseshift