Volpone's Diseases
Volpone has successfully convinced the legacy-hunters Voltore, Corvino, and Corbaccio that he is an ailing and sick old man who will die soon, leaving his heir to inherit his fortune. Of course, the audience knows that Volpone is in fine health and is merely conning the legacy-hunters to add even more to his wealth.
Scoto Mantua
Volpone's disguise as Scoto Mantua is ironic in two ways: first, it presents a situation of dramatic irony, as the other characters do not know that Scoto is simply Volpone in disguise. Second, Scoto Mantua allows Volpone to reveal more of his true, healthy self than his performance as Volpone, a sick and dying man.
Corvino's Jealousy
Corvino is jealous to the point of violence when it comes to his wife, Celia. He berates her for tossing her handkerchief at Scoto Mantua, and bizarrely condemns her to a life of doing everything backwards. However, when Mosca tells Corvino that prostituting his wife will help him gain favor with Volpone, he is more than eager to do so. This ironic reaction emphasizes Corvino's self-involved nature and treatment of Celia as a mere object.
Mosca
Mosca's role in the play is ironic because he is associated with the fly and Volpone the fox. Foxes are traditionally used in literature as symbols of cleverness and slyness, while flies are bottom-feeding nuisances. While Volpone is a conman, the audience slowly learns that he has amassed his fortune largely due to the scheming of Mosca, the presumed "parasite."
