Cerberus is the three-headed dog that guards the entrance of Hades and prevents the people who have crossed the River of Styx from escaping. Each of the heads are said to only like eating live meat and that?s why it allows dead spirits to enter, but not leave the underworld. It is the child of Echidna and Typhon and is said to be related to the Lernaean Hydra, the Nemean Lion, the Sphinx, and the Chimera. Some sources say the heads represent the past, present, and future and others say they represent birth, youth, and old age. Cerberus is often showed with as few as one head to fifty heads and a tail and mane made of snakes. Cerberus is also Hades? loyal watchdog. Heracles? Twelfth Labor