Cerberus, the terror-inspiring offspring of the primordial monsters Typhoeus and Echidna, was the guard dog of the Greek Underworld. In most literary and artistic representations, Cerberus had three heads and a mane of snakes.
Echidna was a primeval female monster, usually represented as a woman from the waist up and a snake from the waist down. She was said to have been the mother of some of the most fearsome monsters of Greek myth, including Cerberus, the Chimera, and the Hydra.
Labor #12: Cerberus Heracles’ final labor was the most daunting: to go down to the Underworld and bring back Cerberus, Hades ’ three-headed guard dog. Against all odds, Heracles was able to cross into the Underworld, wrestle Cerberus, and convince Hades to let him bring the dog to Eurystheus.