Merriam-Webster Collegiate Dictionary - metamorphosis

 noun  (plural metamorphoses)  Etymology: Latin, from Greek metamorphosis, from metamorphoun to transform, from meta- + morphe form  Date: 1533  1.  a. change of physical form, structure, or substance especially by supernatural means  b. a striking alteration in appearance, character, or circumstances  2. a typically marked and more or less abrupt developmental change in the form or structure of an animal (as a butterfly or a frog) occurring subsequent to birth or hatching