In Volpone, how is the theme of metamorphosis related to Volpone and other characters?

Clearly the shape-changing properties of Volpone and other
characters is something that is a vital part of the play as a whole, and is inextricably
intertwined with the theme of deception. If we examine the various examples in the play,
we can see that disguise is sometimes used to conceal, as in the case of Peregine's
gulling of Sir Politic Would-be. However, metamorphosis can also be used to yield
insights into character that are not apparent at first from the "normal" appearance of a
character. This is of course most relevant in Volpone's case, who reveals more of his
vibrancy in his disguise of Scoto Mantua. Most interestingly however, when we think
about the theme of metamorphosis, is the way that assuming and changing identity so much
seems to have a profound impact on character. Changing character so often is shown to
have a definite impact on identity, as is shown by the way that the various guises of
Volpone and Mosca catch up with them in Act V, when their fake identities threaten to
overwhelm their true identities. One of the most poignant moments in the play comes when
Volpone reveals himself, saying "I am Volpone." However, having seen him change through
so many metamorphoses, we as the audience are left wondering who Volpone actually is any
more, as his repeated transformations appeared to have somewhat distilled his character.
It is important to note that the two characters who remain true to themselves are the
two good characters in the play, Celia and Bonario, suggesting the way in which
metamorphoses and disguise are linked to evil.