Barbatos

But according to most sources he is Earl and Duke of Hell. Barbatos rules thirty legions of demons and has four kings as his companions to command his legions. He gives the understanding of the voices of the animals, says past and future, conciliates friends and rulers, and he can led men to hidden treasures that have been hid by the enchantment of magicians.

His name seems to derive from Latin 'barbatus', bearded, old man, philosopher.

See also The Lesser Key of Solomon, Ars Goetia.