The Hydra: The Multi-Headed Serpent of Greek Myth

A multi-headed snake with the power of regeneration and deadly poison, the Hydra was one of the most fearsome monsters in Greek mythology.

It wasn’t alone in this. The Hydra checked all the boxes for a terrible monster in Greek legend: it had snakes, venom, many heads, and was descended from a long line of sea beasts.

But while many monsters in Greek mythology shared attributes with the Hydra, it could claim something no other monster could. It was responsible for the death of the most famous hero ever born.

From its serpentine symbolism to how it inadvertently brought down a demigod, here’s everything you need to know about the multi-headed Hydra!

The Hydra and the Monsters

According to Hesiod, whose early writings on Greek mythology date to the 7th or 8th century BC, the Hydra was one of the terrifying children of Typhon and Echidna.

Typhon was the child of Gaia and Tartarus, the earth and the underworld, and one of the most fearsome foes of the Olympian gods. Descriptions of him vary, but the ancient sources agreed that he was an enormous monster associated with snakes and fire.

He had once tried to view with Zeus for supremacy over the universe. Defeated, the great giant had been imprisoned in Tartarus.

This god-like being was the partner of Echidna, a monster that was half woman and half snake. Her mother was probably Ceto, the primordial sea goddess who birthed the horrors of the deep.

Echidna lived in a cave on the water’s edge, devouring any unlucky being, man or creature, that happened to pass by.

Together, Typhon and Echidna were the parents of many of the most terrifying monsters in Greek mythology. The Hydra, along with the monstrous dogs Cerberus and Orthus, was agreed to be one of these children by nearly every writer.

Later writers added more terrible siblings to Hydra’s family. The Namean Lion, Sphynx, Ladon, Scylla, and the first Gorgon were all given as children of Typhon and Echidna.

Like many of its siblings, the Hydra was a beast with many heads. The number changed between accounts, with the most ancient depictions showing six and later writers increasing the number to as many as fifty.

Unlike the other monsters, however, the Hydra’s heads had a unique property. Whenever a head was cut off, another would grow in its place.

By the time of the Roman Empire, this regenerative ability had grown even more impressive. To writers like Ovid the Hydra grew back two or even three heads for every single one that was destroyed.

This ability made the Hydra a formidable monster that was almost impossible to kill.

In addition to their number and indestructible nature, the heads of the Hydra presented a further challenge.

It could spit a type of venom so powerful that even the scent of its breath could prove deadly. Even when the monster was sleeping, its breath was enough to make anyone who came close die on the spot.

The monster made its home at Lerna, which at the time was the site of a great lake and swampland. The narrow strip of land on which it sat made avoiding the hazards of such terrain almost impossible for anyone passing through.

The lake was said to be bottomless. A later writer said that although the surface of the water appeared calm and peaceful any swimmer who tried to cross the lake was pulled under or swept away.

Like many monsters in the ancient world, the Hydra represented a very real danger in life. Charybdis, for example, represented a real whirlpool.

The Hydra could have been a massive counterpart of real-world water snakes, many of which have deadly venom. Coming upon a nest of snakes or a favorite feeding site could give the impression of a single multi-headed creature that was almost impossible to kill.

In fact, the creature’s name came from the Greek word for water, hydrea.

The Hydra also could have had a more symbolic meaning. The swamps where it made its home could prove just as deadly as any living creature, with difficult terrain and poisonous miasma in the air that could be as harmful as any snake’s venom.

Such swampland could also prove deadly over a longer period of time. As a favorite breeding grounds for mosquitoes and other insects, wet territory like the land surrounding Lerna encouraged the spread of malaria and other diseases.

The Hydra in Greek mythology is often called the Lernaean Hydra to distinguish it from other, similar monsters. Taking the name of the swamp did more than just give the Hydra a location, it tied it to the dangers of the area.

Snakes and the Underworld

Lerna was more than just a marshy lake region, though. In Greek mythology, it was also a portal to the underworld.

These entrances to the underworld were thought to exist all over the living world, hidden in remote and dangerous locations. In addition to the natural dangers, the Greeks believed that such gateways were guarded by fearsome and hideous monsters who would kill any mortal who came too close.

By making its lair at Lerna, the Hydra served as one of many guardians to the realm of the dead. The monsters who watched over these sites served not only to keep the living from wandering into the lands of the dead, but also to make sure the souls of the dead could never escape.

Like the Hydra, many of these monsters had numerous heads to allow them to always have an eye on the gates to Hades’ realm. And, again like the Hydra, they were often associated with snakes.

Its brother Cerberus, for example, guarded the gates that lay beyond the River Styx. Cerberus was a giant multi-headed dog, but its tail was a snake and it was often shown with snakes’ heads protruding from its body.

When Theseus was bound to the Chair of Forgetfulness as punishment for entering the underworld without permission, its straps were said to be serpents that coiled around his body. Snakes were so closely associated with this realm that they were one of the sacred animals and identifying attributes of Hades himself.

The giant Typhus, who led his kin in a war against the Olympians, also had snakes either as a belt or protruding from his skin. Some said that he had taken the rulership of Tartarus, the darkest part of the underworld, after his demise.

In fact, many of the most deadly monsters in the Greek imagination were associated with snakes.

Lamia, who was responsible for the deaths and disappearances of children, was a serpent-tailed woman. Medusa’s hair was a tangle of snakes and her blood gave birth to a breed of enormous vipers.

Apollo and his oracles were associated with snakes after he and Artemis killed the great Python. The Hydra’s own mother, Echidna, had a split serpent tail.

There are hints in the literature than many of these dreadful serpent creatures lived and hunted near portals to the underworld.

The Greeks were not alone in associating snakes with death and the underworld. Living underground and sometimes lashing out with deadly venom, snakes were linked to death around the world.

Heracles Slays the Hydra

The Hydra is remembered for its part in one of the most well-known stories of ancient Greece. Like many monsters of legend, including several of its siblings from Echidna, the Hydra was the subject of one of the twelve labors of Heracles.

The great hero had been hated from the moment he was born by his jealous stepmother, Hera. As his fame grew, she had caused him to be driven mad in an attempt to stop his popularity from increasing any more.

In a frenzy, the legendarily strong demigod had turned against his own wife and children, killing them in cold blood.

Filled with remorse, Heracles had consulted an oracle to learn how he could do penance and atone for the sin of killing his own family. She told him to enter the service of Eurystheus.

The king of Tiryns was the hero’s cousin through their grandfather Perseus. This didn’t mean he was going to treat the hero gently, however.

The king assigned the penitent Heracles a series of nearly impossible tasks to prove his strength, devotion, and will. If Heracles could complete them, he would earn forgiveness and be closer to gaining a place next to his father on Mount Olympus.

Slaying the Hydra was the second of these labors.

Some sources claimed that the Hydra had not been an issue prior to this. Hera raised the monster just to pit it against Heracles, hoping it would kill him.

In this type of myth, Hera and Eurystheus were working together in an attempt to cause the downfall of Heracles. Unable to kill him outright, they hoped the difficult quests they came up with for him would result in his death instead.

The hero set off for Lerna, accompanied by his nephew Iolaus, and found the monster’s lair. He covered his mouth and nose with a cloth to protect himself from the creature’s venomous breath and threw flaming spears into the Hydra’s den to drive it out.

Soon, however, he realized the fight would be much harder than he anticipated. He had not been prepared for how difficult it would be to defeat the regenerating Hydra.

With Iolaos (Iolaus) driving, Herakles rode a chariot to Lerna, and there, stopping the horses, he found the Hydra on a ridge beside the springs of Amymone where she nested. By throwing flaming spears at her he forced her to emerge, and as she did he was able to catch hold. But she hung on to him by wrapping herself round one of his feet, and he was unable to help matters by striking her with his club, for as soon as one head was pounded off two others would grow in its place. Then a giant crab came along to help the Hydra, and bit Herakles on the foot.

-Pseudo-Apollodorus, Bibliotheca 2. 77 – 80 (trans. Aldrich)

Faced with both the invulnerability of the Hydra and the crab that appeared to help it, Heracles realized he was outmatched. His strength and skill would be nothing against a creature whose heads grew back and multiplied faster than he could dispatch them.

In this narrative, he used his trademark heavy club in an attempt to smash the Hydra’s heads. Other depictions had him using a sword or a handheld sickle to slice through the many coiling necks of the creature he fought.

The crab was easy to defeat, he simply crushed it beneath his foot, and had come, or been sent by Hera, simply as a distraction. The many-headed Hydra could not be overcome alone, though.

Heracles called for his nephew to help him, and the clever young man came up with an ingenious way to stop the beast. Perhaps inspired by Athena, he picked up one of the flaming torches they had used to find their way through the marsh.

As Heracles proceeded to cut off each of the monster’s heads, Iolaus followed behind with the firebrand. As soon as a head was removed, he used the torch to cauterize the wound.

By acting so quickly, the wound was closed before a new set of heads could grow from it. At last, Heracles could get ahead of the monster’s regenerative abilities.

Working together, the hero and his nephew quickly defeated the Hydra’s many heads. Only one remained.

According to some versions of the legend, the center head of the monster provided an additional obstacle. This head, unlike the others, could not be killed.

Heracles used his golden sword, a gift from Athena, to remove this last serpentine head. As it continued to wriggle and lash out at him, he placed it beneath an enormous rock to keep it from being a further threat.

The rock remained as a landmark between the town of Lerna and neighboring Elaius. No one ever dared to move it and risk exposing the deadly, still living, head of the Hydra.

His second task complete, Heracles returned to Eurystheus. Unfortunately, the scheming king decided this victory would not count in the hero’s favor.

By receiving help from his nephew, Heracles had failed to complete the task by himself. Eurysthius would make the same claim over the cleaning of the stables of Augeias, the hero’s fifth task, because Heracles was aided by redirecting the waters of two rivers instead of manually cleaning the mess.

Eurystheus would eventually assign Heracles two additional tasks to replace the ones he had gotten help with, bringing the number of quests to twelve. Although he made the last two jobs particularly dangerous, stealing a golden apple of immortality from the Hesperides and bringing Cerberus out of the underworld, Heracles prevailed in the end.

Hera continued to be disappointed in her inability to get rid of her husband’s mortal son. She plagued him throughout his life but was unable to kill him for many years.

The goddess placed the Hydra into the night sky as a constellation to commemorate it. The crab she placed there, as well, as the constellation Cancer.

Venomous Arrows

While he had defeated the monster through both strength and ingenuity, the story of Heracles and the Hydra didn’t completely end with the creature’s decapitations.

After destroying the great snake creature, Heracles saw a use for its potent venom. Before he left Lerna he dipped his arrows into the Hydra’s blood.

These poisoned arrows would service Heracles well in his later adventures. He used them many times in both the labors assigned by Eurystheus and other fights.

• Defeating the Stymphalian Birds – The hero’s sixth labor was to drive these vicious birds, that were sacred to Ares, out of Arcadia. On Athena’s advice he used a rattle to startle them into the air, shooting as many as he could with his poisoned arrows. The rest fled.
• The death of Geryon – Fetching one of the three-headed giant’s cattle was the tenth labor of Heracles. He shot at the giant with his arrows, firing with such strength that he completely pierced through Geryon’s forehead.
• Killing the dragon – In his eleventh labor, sources vary on whether he encountered the dragon Lakon or not. In those that say he did, he killed the serpent with an arrow.
• Freeing Prometheus – While on his way to the Hesperides’ garden, Heracles killed the eagle that had eternally eaten the Titan’s liver by shooting it down.
• Killing the centaur Nessus – In keeping with the traditional behavior of his race, the centaur tried to abduct Heracles’ wife as he helped her across a river. The hero shot him from the riverbank before he could get away.

The death of Nessus by the Hydra’s poison would eventually lead to the downfall of Heracles himself.

As the centaur lay dying from the toxins on the arrow, he cleverly came up with a way to get his revenge on Heracles. He gave his bloody robe to the hero’s wife, Deianira, telling her that centaur blood acted as a love potion.

The death also left a stain on the earth itself. The river they had tried to cross, the Anigrus, was said to have developed a terrible smell because the Hydra’s poisonous blood had contaminated it.

Deianira held onto the centaur’s robe for years, until the day that a rumor reached her that Heracles had fallen in love with another woman, Iole.

Hoping to rekindle her husband’s love for her and make him forget about his newest mistress, she gave him the blood-stained robe.

What Deianira had not anticipated was that the Hydra’s poison had been released into the centaur’s bloodstream when he was shot. The blood on the robe was tainted with a terrible poison.

When Heracles put on that robe, it began to burn his skin. Searing him to the bone, the poison nearly drove the hero mad with pain.

With death upon him, Heracles began to rip up trees. He used them to build his own funeral pyre.

As the poison ate away at his body, Heracles threw himself onto the pyre. The hero had finally been defeated through a combination of the Hydra’s venom and the centaur’s schemes.

His wife, realizing what she had done, killed herself in despair. Before his death, Heracles had made his son Hyllus vow to marry Iole so she would not be left alone.

This was not the end of Heracles, however. He had achieved redemption and been accepted as the son of Zeus.

The flames that were meant to cremate him burned away only his mortal half. The divine part of him that came from Zeus remained.

The death of mortal Heracles by the Hydra’s poison completed his apotheosis, his transformation into a god. Now fully divine, he ascended to Olympus to take his place among the ruling gods.

Philoctetes, the only one among the hero’s friends who had been willing to light his funeral pyre, received his legendary bow for his service. The last poisoned arrow would be used by him to kill Paris at the height of the Trojan War.

The Hydra in the Near East

Like many myths of ancient Greece, the story of the Hydra has its roots far deeper in history. To trace the origins of the Hydra, one has to look beyond the Mediterranean and to the ancient cultures of Mesopotamia.

The closely-related civilisations of Assyria, Babylon, and Sumer gave rise to many of the legends and deities that were eventually seen in Greece and throughout Europe.

One of the most popular deities in ancient Mesopotamia was Ninurta, a god of hunting, agriculture, war, and law. His strength and exploits made him particularly loved by the Assyrians.

One of Ninurta’s famous stories was his expedition into the mountains, during which he was credited for slaying eleven terrifying monsters. The tale of Ninurta has obvious parallels to that of Heracles.

The Assyrian god was said to have killed wild bulls and the monstrous Anzu bird, and captured a set of prized cows. Compare those to Heracles’ labors of capturing the Cretan bull, driving off the Stymphalian birds and killing the eagle that tormented Prometheus, and stealing Geryon’s cows and the stories have obvious similarities.

The most apparent similarity, however, is in the snakes killed by both Heracles and Ninurta.

While the surviving poems don’t give details of the battle, one of the monsters Ninurta killed was a seven-headed serpent. The snake was later described as one of his weapons, perhaps being used in the same way the Hydra’s venom was used by Heracles.

Like the Hydra, the serpent of Mesopotamian mythology belonged to a family of monsters. The three horned snakes of the Assyrians were connected just as the many snake-like creatures birthed by Echidna were.

Basmu was another of these serpents, also killed on Ninurta’s trek into the mountains. It was described as having seven tongues in six mouths.

The Mesopotamians, like the Greeks, memorialized their great monsters and warriors in the sky. The Akkadians placed Basmu in the stars, creating the same constellation as the Greek Hydra.

The Many-Headed Serpent Today

Today, the word “hydra” lives on more for its association with many limbs and regeneration than the incredible feat of Heracles and his nephew. It is often used in science.

Of course, the constellations of Hydra and Cancer remain today. A later constellation, first presented in the 16th century, was named Hydrus as a male counterpart to the female water snake mapped by the Greeks.

The name was also given in astronomy to one of the moons of the dwarf exoplanet Pluto. The scientists who named it said that one reason they chose the name was because the nine heads of the mythical serpent were a subtle reference to Pluto’s former status as the ninth planet in the solar system.

All the moons of Pluto reference monsters and deities of the Greek underworld, in honor of the planet being named for the Roman equivalent of Hades. Hydra is joined by Charon, Kerberos, Styx, and Nix.

Hydra is also the name given to a genus of freshwater hydrozoa. These microscopic organisms are defined by their branching shape and regenerative capabilities.

Scientists have discovered that these hydrae appear not to age. Their ability to generate, like their namesake, makes them immune from both minor injury and cellular degeneration.

These tiny hydrae even share their namesake’s toxicity. Each of the creature’s tentacles contains a structure called a nematocyst which, when triggered, releases a dart of neurotoxin that paralyzes prey and predators.

The mythical monster’s connection to water and the sea has lived on in the names of many ships and ship classes around the world. The British Royal Navy and the Greek Navy have named ships Hydra since the 18th century.

The most recent Hydra in the British fleet was not a warship, but rather one dedicated to scientific research. The HMS Hydra was launched in 1965 as an oceanic survey vessel and is still in use under a different name in Indonesia.

Its motto was the Latin phrase Ut Herculis Perseverantia – “Like Hercules Persevere.”

In mathematics, the Hydra game was developed as a logic exercise in relation to Goodstein’s theorem. Under the theory’s assumption that every Goodstein sequence eventually terminates in 0, the game posits that with enough time Heracles would eventually be able to chop off more heads than the monster could regrow.

In computing the name has been given to any program or site that branches out. It was both a far-reaching virus and the new name of the Pirate Bay sharing site when it split into six domains.

Of course, the Hydra is not remembered only for its interest to scientists and sailors. The monster remains a popular inspiration in works of fiction and art.

Hydra is both the name of an evil corporation and an individual villainess in the Marvel comic book universe.

In the complex fictional world created by H.P. Lovecraft, Mother Hydra is one of the rulers of the Deep Ones. With the more infamous Cthulu, she is one of the largest and oldest of these mysterious ocean entities.

Like many other Greek monsters, the Hydra has also inspired countless enemies in video and tabletop games as well as cartoons.

Over two thousand years after it appeared in mythology, the Lernaean Hydra continues to inspire with its branching heads and power to regenerate and heal.

The Hydra as the Ultimate Monster

Part of the Hydra’s enduring appeal may be how many of our fears it touches on.

The monsters of Greek mythology often represented very specific dangers or elements. The Hydra was no different, serving as a symbol for both water serpents and the dangerous swamps they inhabited.

As our culture has changed, some of these innate fears have not.

The Hydra is still a frightening creature, even though most people no longer have a reason to be afraid of its specific home.

Snakes are a common motif in horror because they are one of mankind’s most widespread fears. The Greek monsters so often had serpentine attributes because these automatically signalled danger.

Beyond that, the Hydra’s many heads are instantly recognizable as monstrous and unnatural. Bringing to mind a whole nest of snakes instead of a singular threat, they make the monster even more frightening.

Some legendary monsters, like the Chimera or Lamia, are far removed from our modern notions of real danger. They are pure fantasy. The Hydra, however, still strikes a modern audience as abhorrent.

The image of Heracles fighting the Hydra conjures a nightmare that almost anyone can relate to – fighting off a snake only to realize that more and more keep coming.

While the Hydra may have symbolized a very specific fear in the original myth, it remains one of the most frightening monsters in mythology because it reminds us still of a fear we could one day face.