Heracles Labors: The Lernean Hydra.
     Offspring of Echidna and Typhon, the hydra was a poisonous water snake that lived in the marshes at Lerna. It had numerous heads, one of which was immortal; if one of the heads was cut off, two new heads grew in its place. As his second labor, Heracles (Hercules) was sent to destroy the hydra, a task made more difficult when Hera sent a giant crab to fight alongside the monster. Heracles killed the crab but required the assistance of his nephew Iolaus to complete his task. Each time the hero cut off one of the hydra’s heads, Iolaus cauterized the stump with a hot poker so that no new head would grow. Finally, Heracles severed the immortal head and buried it under a large rock. He then dipped his arrows in the hydra’s blood, poisoning them for later use.

Further Reference:
Galinsky, G. Karl. 1972. The Herakles Theme: The Adaptations of the Hero in Literature from Homer to the Twentieth Century. Totowa, N.J., Rowman & Littlefield.


Listings for Heracles' Labors are arranged under the following headings:
Heracles Labors, General List
The Nemean Lion
The Lernean Hydra
The Erymanthian Boar
The Ceryneian Hind
The Stymphalian Birds
The Stables of Augeas
Heracles and Antaeus
The Cretan Bull
The Mares of Diomedes
The Girdle of Hippolyta
The Cattle of Geryon
The Apples of the Hesperides
Cerberus

For Heracles entries generally:
Heracles