Cancer from the Greek for "the Crab", Karkinos which in Latin is Cancer. One of Hera's pet monsters, whom Hercules crushed in his second labour. Thus, cancer was originally referred to as "the Asses' Crib". In many ways, this star sign hasn't got the most fortunate etymology or the most glowing myth behind it.
Cancer is also associated with the Greco-Roman goddess Selene/Luna and sometimes the goddesses Artemis/Diana and Hecate/Trivia.In Greek mythology the Crab was given its place in heaven by the Mother Deity, Hera. This was gained through the crab's involvement in the second Herculean task of slaying the monstrous Hydra. While this battle was taking place, the Crab bit Hercules in the foot and was then stomped to death by the great giant. Hera, who was antagonistic to Hercules's ventures, was so pleased with the Crab that she promptly granted him immortality and placed in the Zodiac.