The Lernaean Hydra is one of the most iconic monsters of all Greek mythological tales, and was famously encountered by Heracles in his labours.

The Hydra was the monstrous offspring of Typhon and Echidna, but like its sibling, the Nemean Lion, the Hydra was raised to maturity by the goddess Hera. Hera was raising the monster to specifically to do away with Heracles, the illegitimate offspring of her husband Zeus.

Once matured the Hydra was transported to the region of Lerna on the east coast of the Peloponnese. This region was noted for its springs, lakes and swamps, and was originally noted for its water purity. Beneath the largest lake was also one of the entrances to the underworld, which the Hydra was said to guard, but the Hydra was also known to ravage the surrounding area, killing the unwary. Subsequently the Hydra would be known as the Lernaean Hydra.

The Lernaean Hydra was described as a reptilian water serpent, but notably had nine heads that exhaled poisonous fumes. The head in the middle of the nine was also said to be immortal. As well as ravaging the area, the presence of the Hydra in the swamps and lakes of the region, was also said to be poisoning the pure waters.

Eventually the Greek hero Heracles would venture into Lerna; Heracles having been dispatched by King Eurystheus on the seemingly impossible task of killing the monster.

Entering the realm of the Hydra, Heracles protected himself from the poisonous breath, by wrapping his nose and mouth in fabric. Then the Greek hero forced the monster from its den by firing fiery arrows into it. Heracles was then faced with the nine-headed serpent.

Heracles took up his sword and cut off one of the Hydra’s heads; the hero then encountered his next problem, because from the severed neck emerged two new heads.

It was one of Heracles companions, Iolaus, his nephew, who came up with a plan to deal with the problem. When Heracles subsequently cut off a Hydra head, Iolaus would cauterise the neck before new heads could grow. In this way Heracles was eventually left with the single immortal head to deal with.

Hera though observed the fight, and anxious to cause Heracles more problems, sent forth a giant crab, Karkinos, to distract the hero. The giant crab proved no match for the hero though, especially when compared with the Hydra, and Heracles crushed the crustacean.

The final immortal head of the Lernaean Hydra was eventually removed with a special golden sword; a sword that the goddess Athena had presented to the hero. The decapitated head was then buried beneath a massive rock on the road between Lerna and Elaeus.

Hera would place depictions of her monsters amongst the stars so that they could live on forever, and the Lernaean Hydra would become the constellation Hydra, whilst the crab would become Cancer.

On his return to King Eurystheus, Heracles discovered that his efforts were in vain, as the king decreed that because the hero had been assisted in his task, the labour was null and void.

In later Greek mythology the Hydra was transferred from being a guardian of an entrance to the underworld, to a guardian within the underworld. The suggestion being, that even after death it too made its way into the realm of Hades, and would ensure that no one left, just like Cerberus did.

Even after death, the Lernaean Hydra would appear in many stories, or at least its poisonous blood would. Heracles would dip the tips of his arrows into it before returning to Tyrins and the court of Eurystheus. The poison would inflict wounds that were incurable, and Heracles would use those arrows against Geryon and the fighting centaurs, amongst others.

Famously though it was the wisest centaur at all who was killed accidentally by the weapon of Heracles. Chiron was accidentally pricked by an arrow, and though immortal, would give up his immortality because of the pain that the poison inflicted. Heracles himself was also killed by the Hydra’s poison, as his wife, Deianira, was tricked into presenting her husband a robe coated in its poison.

The bow and arrows of Heracles would also see action during the Trojan War, when the weapons of the Greek hero were taken up by Philoctetes, and were then used famously to kill Paris.

Even though it appeared primarily in only one story, the Lernaean Hydra remains one of Greek mythology’s most famous monsters, and is recognisable as Cerberus.