The twelfth and final of Heracles' twelve labors was to capture Cerberus. Cerberus was a vicious three-headed hound, with a snake for a tail, who guarded the gates of Hades and the Underworld. It was Cerberus' job to make sure that the dead did not escape the Underworld, and that the living did not enter into it.
After learning how to enter and lave the Underworld alive at Eleusis, Heracles was assisted by Hermes and Athena at the entrance, which included getting by Charon.
Heracles made his way to the throne of Hades, where he asked his permission to take Cerberus. Hades agreed, on the condition that Heracles not hurt the dog.
Heracles wrestled Cerberus to the ground, tiring the hound enough to drag it back to the living world. When Heracles arrived at his destination, Eurystheus was so scared of the fearsome beast that he jumped into a large urn and hid from it.
