Who is Mosca in the novel, Volpone?

Mosca (also called The Gadfly) is Volpone's flatterer, who plots against everyone else. He is malicious but also very witty. It is Mosca's job to convince each gift-giver that he or she will be the honored recipient of Volpone's will. Mosca carries out Volpone's plans, but he also conceives of pranks that take his master's plots just one step further.