Introduced in B83 as part of Shapeshifting, opposite Morph.

This versatile advantage can occur as part of many powers. The most obvious of these are supernatural; for example, a divine power that lets a priest take on the forms associated with his god, or a spirit power that enables a shaman to become a totem animal. A dimension travel power might give the wielder the ability to appear in different bodies, storing unused ones “elsewhere” for the duration. And a body-control power could give the user enough control that he can turn into something else. mentions Disadvantageous Alternate Forms.