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
Drakaina (mythology) generally slain only by gods or demigods. Zeus slew Delphyne and Campe, Apollo slew Python, and Argus Panoptes slew Echidna. Echidna was the mother of a huge brood of monsters, including other dragon-like creatures. According to Hesiod, Echidna gave birth to Cerberus, Orthrus, the Chimera, the Nemean lion, the Sphinx and the Hydra. (Other ancient authors, such as Hyginus, attribute even more monsters as children of Echidna such as the Caucasian eagle, the Crommyonian Sow, the Colchian dragon, the Harpies and Scylla.) Drakaina (mythology) In Greek mythology, a drakaina () is a female serpent or dragon, sometimes with humanlike features.