Circe, Ulysses [Odysseus] and Mercury [Hermes]. Etching by P. Aquila after Annibale Carracci.

Painting in the Camerino Farnese, Palazzo Farnese, Rome. In Homer's "Odyssey" (Book 10), Odysseus and his companions land on Circe's island. Circe was a witch, who gave travellers a magic potion which turn them into animals. Some of Odysseus's companions fell into this trap, but not Odysseus who had been forewarned by Hermes