The Mythical Greek Hydra was a serpentine water beast that had multiple heads, the guardian of the underworld the Hydra was a formidable foe and deadly in multiple ways. Not only could the Hydra strike with many of its heads, each snake like head contained sharp teeth, and poisonous breath deadly to humans. Worse still, were you to try and defend yourself against the Hydra, with a sword or similar edged weapon, if you cut off one of the Hydras many head, two would grow back in its place.