Magical ones with high tech, I suppose -- that is, blatantly and obviously magic, and not psionics.
But some quirks are hard to match. Unless the metaorigin is the volitional choice of some being, it's hard to see how it could imitate the selkies or other shapeshifters of legend that need some article to change shape. Anything from mutations to infection to radiation. . . .
Shapeshifting itself is fine, but trinkets are not.
