metamorphosis

n. change in form or structure; result of a complete change in appearance; change or succession of changes in an organism which enables it to survive in a new environment (Zoology); change in form or function of a plant during its development (Botany)

Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's form or structure through cell growth and differentiation. Some insects, amphibians, molluscs, crustaceans, cnidarians, echinoderms and tunicates undergo metamorphosis, which is usually (but not always) accompanied by a change of habitat or behaviour.
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Metamorphosis /meta·mor·pho·sis/ change of structure or shape, particularly, transition from one developmental stage to another, as from larva to [more]Metamorphosis - Community and Resources

Noun
1. the marked and rapid transformation of a larva into an adult that occurs in some animals
(synonym) metabolism
(hypernym) organic process, biological process
(hyponym) hemimetamorphosis, hemimetabolism, hemimetaboly
2. a striking change in appearance or character or circumstances; "the metamorphosis of the old house into something new and exciting"
(synonym) transfiguration
(hypernym) revision, alteration
3. a complete change of physical form or substance especially as by magic or witchcraft
(hypernym) transformation, translation

(n.)
The change of material of one kind into another through the agency of the living organism; metabolism.
  

(n.)
Change of form, or structure; transformation.
  

(n.)
A change in the form or function of a living organism, by a natural process of growth or development; as, the metamorphosis of the yolk into the embryo, of a tadpole into a frog, or of a bud into a blossom. Especially, that form of sexual reproduction in which an embryo undergoes a series of marked changes of external form, as the chrysalis stage, pupa stage, etc., in insects. In these intermediate stages sexual reproduction is usually impossible, but they ultimately pass into final and sexually developed forms, from the union of which organisms are produced which pass through the same cycle of changes. See Transformation.