Hylas was the son of King Theiodamas of the Dryopians. After Hercules killed Hylas’s father, Hylas became a companion of Hercules. They both became Argonauts, accompanying Jason in his quest on his ship Argo in seeking the Golden Fleece. During the journey, Hylas was sent to find fresh water. He found a pond occupied by Naiads, and they lured Hylas into the water and he disappeared.