Lernaean Hydra
Generation VI · Many-headed serpent of Lerna
The Hydra was a poisonous water serpent reared by Hera in the marshes of Lerna, near a reputed mouth of the underworld, and for every head cut off, more grew in its place. Heracles mastered her in his second labour with his nephew Iolaus searing each stump with fire, and afterward dipped his arrows in her venom — a poison that would echo through his later stories.