To transform from a larval stage such as a tadpole to an adult stage such as an adult frog. First stage and last stage tend to look very different from each other. Found on http://www.conservewildlifenj.org/glossary/
Met`a·mor'phose transitive verb [ imperfect & past participle Metamorphosed ; present participle & verbal noun Metamorphosing .] [ Confer French métamorphoser .] To change into a different form; to transform; to transmute. «... Found on http://www.encyclo.co.uk/webster/M/56