The Lernaen Hydra depicted in a Roman mosaic (c. 2nd AD).
The Hydra was a fabulous monster of the ancient world, said to have inhabited the marshes of Lernaea, in Argolis, not far from the sea-coast. Accounts vary both as to its origin and appearance. Some make it the issue of Styx and the Titan Pallas, and others, of Echidna and Typhon. It is represented as having several heads, which immediately grew up again as often as they were cut off. The number generally ranged from seven to nine, though Simonides gives it fifty, and some historians a hundred, and even more. Its mouth, which were as numerous as its heads, discharged a subtle and deadly venom. The destruction of this reptile was one of the twelve labors of Hercules.