Lernaean Hydra that Hera placed the Hydra and crab as constellations in the night sky after Heracles slew him. When the sun is in the sign of Cancer (Latin for "The Crab"), the constellation Hydra has its head nearby. In fact, both constellations derived from the earlier Babylonian signs: Bashmu ("The Venomous Snake") and Alluttu ("The Crayfish"). Primary sources Secondary sources Lernaean Hydra The Lernaean Hydra or Hydra of Lerna (, "Lernaîa Hýdra"), more often known simply as the Hydra, is a serpentine water monster in Greek and Roman mythology. Its lair was the lake of Lerna in the Argolid, which was
Lerna Lerna In classical Greece, Lerna () was a region of springs and a former lake near the east coast of the Peloponnesus, south of Argos. Even though much of the area is marshy, Lerna is located on a geographically narrow point between mountains and the ocean, along an ancient route from the Argolid to the southern Peloponnese; this location could have potentially resulted in the importance of the settlement. Its site near the village Mili at the Argolic Gulf is most famous as the lair of the Lernaean Hydra, the chthonic many-headed water snake, a creature of great antiquity when