Ah, never had heard of her, but looking into it she's got a really neat hook. If I had managed to ever get into Marvel / DC stuff, I would have probably really liked her. I actually like the fact that she doesn't magically retain / regrow her clothes after her changes - no Hulk Magic Pants with her!
So that's a shapeshifter that shapeshifts by tearing away her old form as a form of mask or shell (or, er, husk) to reveal the new form underneath. Definitely a rare concept. It's also not dissimilar to how the Soap Satyri have been shown to end up in their permanent form - wonder if that's how the Succubi do major shapeshifts that don't include glamours?