Leucosia was a resident of the village of Parthus. She was beloved by Zeus who gifted her a golden chalice. In jealousy, Hera cursed Parthus and turned Leucosia into a dog. Leucosia lived alone in Parthus as a dog until a group of homeless villagers attempted to settle there. Finding the village cursed, the villagers left, led by Hercules, to re-settle in the charmed city of Calydon. At this point, Leucosia left Parthus as well and became a traveling companion of the blind seer, Tiresias.