Iolaus was Heracles' nephew, constant companion, and eromenos or boy-lover. (This sort of relationship between an older male and a teenage boy was common in ancient Greek culture.) Iolaus is most famous for helping Heracles defeat the Hydra, by cauterizing the neck-stubs of the beast as Heracles chopped off each of its many heads. In the ancient city of Thebes, there was a shrine Iolaus right beside the one for Heracles, and there was a festival named in his honor. He's even a major character in the Hercules: The Legendary Journeys TV series.