First seen and where the Hydra lives:
The Hydra is the offspring of Typhon and Echidna. The Hydra was raised by Hera. The Hydra lived in the marsh lands of Lerna. Lerna is a spring filled marsh and scene of a former lake.
The Hydra is know for terrorize small villages.
The Hydra is a serpent like water monster with similar traits to a reptile.
qIf you slay the Hydra, you will be rewarded with full ownership to the Hydra's underwater cave and access to the Under World.