Hydra is a nine-headed sea serpent who guards the entrance to the Underworld from Earth, called Lerna. Her breath, blood, and saliva are poisonous, and her heads regenerate when they are severed.
The Hydra was the sister of Chimera and Cerberus, another hideous creature forged by the union of parents Typhon and Echidna. She was a nine-headed sea serpent whose breath, blood, and saliva were so poisonous that even her scent can be deadly. She is most well-known in Heracles’ tale of his Twelve Labors. Heracles had to atone for killing his children when he went through a fit of madness sent by the goddess Hera. He served King Eurystheus, who gave him Twelve Labors, or tasks, to complete.
Heracles’ Second Labor was to kill the great serpent. He went to the Lerna swamp, which was said to be an entrance to the Underworld from Earth. He attacked the serpent with clubs, arrows, and finally began cutting off her heads; however, whenever he cut off one head, two heads regenerated in its place. Assisted by his nephew Iolaos, he began a fire with sticks. Then, every time he cut off a head of Hydra, he cauterized the wound with the burning sticks, preventing them from growing back.
Hydra had one immortal head, which Heracles hid under a great mountain. He also kept some of Hydra’s poisonous saliva to tip his arrows with.
Typhon and Echinda
Nine-headed sea serpent with poisonous breath, blood, and saliva.