24. Shape shifter: N. a common theme in mythology and folklore, as well as in science fiction and fantasy. In its broadest sense, it is a metamorphosis (change in the physical form or shape) of a person or animal. Shapeshifting involves physical changes such as alterations of age, gender, race, or general appearance or changes between human form and that of an animal (therianthropy), plant, or inanimate object.
shift: v. O.E. sciftan "arrange, divide," related to sceadan "divide, separate" (see shed (v.)), from P.Gmc. *skiftanan (cf. O.N. skipta "to divide, change, separate," O.Fris. skifta "to decide, determine, test," Du. schiften "to divide, turn," Ger. schichten "to classify," Schicht "shift"). Sense of "change" appeared c.1250; that of "move, transfer" is c.1375; that of "manage to get along" is first attested 1513, in phrase shift for oneself, and yielded shiftless in the modern sense (1584).
25. Metamorphosis. n. 1533, "change of form or shape, especially by witchcraft," from L., from Gk. metamorphosis "a transforming," from metamorphoun "to transform," from meta- "change" (see meta-) + morphe "form" (see morphine). Metamorphic, in geological sense, is first attested 1833, in Lyell; rocks whose form has been changed by heat or pressure.