This is the mask of "Brighella", "first zanni" of Bergamo and one of the most disturbing of the Commedia characters.
Brighella is a crafty, quick, unscrupulous servant who was often paired with Arlecchino. He thrives on double dealings, intrigues, and foul play. Having the highest status of the servants, he is sometimes depicted as an innkeeper, shop owner, valet, or soldier--cunningly separating patrons from their cash and possessions. He is a cynical liar who only looks out for himself, and is never repentant when caught in wrongdoing. He is sleazy, seductive, dangerous. He executes his crimes ingeniously. He offers assistance to innocents, scoping opportunities to steal from the unsuspecting. Money for him is worth only the pleasure it provides and he loves nothing but his own pleasure. He is a drunkard and boisterous debaucherer who readily insults anyone weaker. With stronger men, he fawns on them or shrewdly slips away.
Brighella is lazy but can move quickly, almost imperceptively. He slinks without muscular effort, and he stays still, ready to pounce. He might blithely be cleaning his nails with the knife which will soon cut a throat. He is very powerful but conserves his energy. He sleeps with one eye open. He gets very close to people when he speaks. He can sing and dance, and drink with the best of them. His costume is usually trimmed in green.
A comparable animal image for Brighella is a rat, snake, or large cat.