The Lernaean Hydra was monsters of Greek mythology, a serpentine water-monster that lived in the swamp of Lerna, near the city of Argos, in the eastern Peloponnese. The Hydra had many heads, and the number varies in different sources, but most commonly nine. For every head that was cut off, two would grow in its place, making the creature nearly impossible to kill. The Hydra was the offspring of the monsters Typhon and Echidna, and it was the brother of Cerberus, the Chimera, the Nemean Lion, and the Sphinx. It was the second of the Twelve Labors of Heracles.
The Lernaean Hydra is the second of the Twelve Labors of Heracles, the multi-headed serpent of the swamp of Lerna near Argos, and the sister-monster of Cerberus, the Chimera, and the Nemean Lion, the four great monsters of the canonical Greek tradition. The standard source for the Heracles labour is the Bibliotheca of Apollodorus (2.5.2, the second labor); Hesiod’s Theogony (line 313 ff.) makes the Hydra a child of Typhon and Echidna, and gives the nine heads that became the standard number in the later tradition. The myth has had a long afterlife in modern biology, where the Hydra genus (named by Linnaeus in 1758) is a freshwater animal capable of regenerating entire body parts.
The Origins of the Hydra
The Lernaean Hydra was the offspring of two of the most fearsome monsters in Greek myth: Typhon, the last son of Gaia and Tartarus, who challenged Zeus for the rule of the cosmos; and Echidna, half-woman and half-snake, the “mother of all monsters.” The Hydra was thus the brother of Cerberus, the three-headed dog of the underworld; the Chimera, a fire-breathing creature with the head of a lion, the body of a goat, and the tail of a snake; the Nemean Lion, an invulnerable lion; the Sphinx, the riddling creature that terrorized Thebes; the Caucasian Eagle, the bird that ate Prometheus; and many other famous monsters.
The Hydra lived in the swamp of Lerna, a region of caves and fresh-water springs near the city of Argos in the eastern Peloponnese. The swamp was associated with death and the underworld, and it was one of the entrances to the realm of Hades. The Hydra was said to be a guardian of this entrance.
The Second Labor of Heracles
The Hydra was the second of the Twelve Labors of Heracles. After strangling the Nemean Lion, Heracles was sent by King Eurystheus to slay the Lernaean Hydra, which was terrorizing the region of Lerna, killing cattle and ravaging the countryside.
Heracles traveled to Lerna, where he found the Hydra in its cave. He began to club the creature, but every time he cut off a head, two more grew in its place. To defeat the Hydra, Heracles had his nephew Iolaus cauterize each neck with a burning brand as he cut off the head, preventing regrowth. With this method, he was finally able to kill the creature.
According to the most familiar version of the myth, Heracles then cut off the one immortal head of the Hydra and buried it under a great rock beside the road leading from Lerna to Elaeus. He also dipped his arrows in the Hydra’s poisonous blood, which would later become an important weapon in his arsenal. One of these arrows would eventually cause his own death.
The Help of the Crab
In one version of the myth, the goddess Hera, who hated Heracles, sent a giant crab to help the Hydra in its fight against the hero. The crab bit Heracles on the foot, but he crushed it. Hera, grateful for the crab’s help, placed it among the stars as the constellation Cancer. The myth is the supposed origin of the constellation, which was associated with the summer solstice and the hot, dry season that the Greeks believed was caused by the sun’s retreat from the earth.
The Poisonous Blood
The blood of the Hydra was extremely poisonous. After slaying the creature, Heracles dipped his arrows in the blood, and the poison made them deadly. He used these arrows to kill many of his enemies, including the centaur Nessus, who tried to rape his wife Deianira. Before he died, Nessus tricked Deianira into thinking that his blood was a love charm, and she smeared it on a robe. When Heracles wore the robe, the poison burned his flesh, and he eventually died in agony, building a pyre on Mount Oeta and allowing his mortal part to be burned away.
The poison of the Hydra has also been used in modern medicine. The Hydra was the source of inspiration for the genus Hydra, a small freshwater animal that can regenerate body parts and is used in biological research. The Hydra is also the origin of the medical symbol of the Bowl of Hygieia, the cup with a snake, which is the symbol of pharmacy (in contrast to the Caduceus, the staff with two snakes, which is the symbol of medicine, derived from Hermes).
The Hydra in Greek Art
The Hydra was a popular subject in Greek art, particularly in pottery. It is often shown as a serpent with many heads, the heads being snaky and the body coiled. The famous François Vase, dating to around 570 BCE, includes a depiction of Heracles fighting the Hydra. The hydria, a type of Greek water jar, takes its name from the Hydra, since water was traditionally drawn from wells, which were often associated with chthonic monsters.
The Hydra also appears on coins from Lerna, the city near which it lived, and in various reliefs and sculptures. The most famous surviving depiction is the metope from the temple of Zeus at Olympia, which shows Heracles holding up the Hydra while Iolaus cauterizes the necks with torches.
The Hydra in Astrology and Astronomy
The constellation Cancer, the crab, was said to have been placed among the stars by Hera for its help in the fight between Heracles and the Hydra. The constellation is the faintest of the twelve zodiac signs, and it is associated with the summer solstice, the hot season, and the time when the sun was believed to retreat from the earth.
The Hydra is also a constellation in its own right, the largest constellation in the night sky. It winds from the southern sky to the northern sky, and it contains several notable stars and deep-sky objects. The constellation is named for the Lernaean Hydra, and it is often depicted as a multi-headed snake.
The Hydra in Modern Language and Thought
The word “hydra” has come to mean any complex, persistent problem that seems to grow worse as you try to solve it. The phrase “hydra-headed” describes a problem that produces new difficulties as fast as old ones are resolved. The word is widely used in politics, business, and technology, particularly to describe problems that resist simple solutions.
The Hydra has also been used as a symbol of resistance and regeneration. The Warsaw Uprising of 1944 used the Hydra as a symbol, and the coat of arms of Ukraine features a trident, a symbol that has been connected to the Hydra in some interpretations. The hydra is also used in computer science, biology, and engineering to describe systems that can regenerate after damage.
The Legacy of the Hydra
The Hydra is a recurring enemy in the God of War franchise, the source of the biological genus Hydra (named by Linnaeus), and the namesake of the Marvel villain organisation Hydra in the Marvel Cinematic Universe. The phrase ‘cut off one head, two more shall take its place’ has entered English as a description of problems that grow worse as you try to solve them. For the broader modern reception, see our guide to Greek mythology in modern culture.
A Note on Reading This Profile
A note on reading this profile. The Hydra of the Greek sources is one of the most carefully described of the Greek monsters, and the Bibliotheca of Apollodorus (2.5.2) gives the most complete account. The standard scholarly reading is that the labour of the Hydra is a rite-of-passage labour, the labour in which Heracles proves that he can defeat a regenerating monster (the heads grow back two for one cut), and the lesson is the real-world one: that a problem solved may produce two more problems if not solved correctly. The phrase hydra-headed in modern English, meaning a problem that grows worse as you try to solve it, is a direct inheritance.