Faunus was the Roman horned god of the forest, plains and fields. When he made the cattle fertile he was called Inuus. He came to be equated in literature with Pan – the Greek god.
Faunus was one of the oldest Roman deities. According to the epic poet Virgil, he was a legendary king of the Latins who came with his people from Arcadia.
Faunus revealed the future in dreams and voices that were communicated to the people who slept in his precincts, lying on the fleeces of sacrificed lambs.
Faunus was naturally equated with the god Pan, who was a pastoral god of shepherds who was said to reside in Arcadia. Pan had always been depicted with horns and as such many depictions of Faunus also began to display this trait.
However, the two deities were also considered separate by many, for instance, the epic poet Virgil in his Aeneid made mention of both Faunus and Pan independently.