The vulture is one of the three birds of prey that circle around the fox, greedy and full of expectation. He is a lawyer and consequently has a weakness for wills. He uses his legal knowledge to advocate injustice in order to possess Volpone's fortune. Mosca wisely fools this gull by employing the advocate's own tactics; that is, he tells Voltore the biggest lie and documents it with elements of well-known facts.
Voltore is tricked by his own folly. He can, he believes, with quick agility, make the wide world believe that a lie is the truth. He fails to observe that he, as part of the wide world, might be cozened himself.