Hades’ three-headed dog. Cerberus guards the entrance to the Underworld. Offspring of Typhon and Echidna. Cerberus allowed the spirits of the dead to enter the Underworld but did not permit them to exit. Orpheus was able to get past Cerberus by lulling him to sleep with a lyre. In order to complete the last of his Twelve Labors, Heracles was also able to remove Cerberus from his post by luring him into the land of the living.