Illustrations
The modern symbol for Cancer represents the pincers of a crab, but Cancer has been represented as various types of creatures, usually those living in the water, and always those with an exoskeleton.
In the Egyptian records of about 2000 BC it was described as Scarabaeus (Scarab), the sacred emblem of immortality. In Babylonia the constellation was known as MUL.AL.LUL, a name which can refer to both a crab and a snapping turtle. On boundary stones, the image of a turtle or tortoise appears quite regularly and it is believed that this represent Cancer as a conventional crab has not so far been discovered on any of these monuments. There also appears to be a strong connection between the Babylonian constellation and ideas of death and a passage to the underworld, which may be the origin of these ideas in much later Greek myths associated with Hercules and the Hydra. In the 12th century, an illustrated astronomical manuscript shows it as a water beetle. Albumasar writes of this sign in the work published in 1489 as a large crayfish. Jakob Bartsch and Stanislaus Lubienitzki, in the 17th century, described it as a lobster.
Read more about this topic: Cancer (constellation)