Entity
Cerberus
The many-headed hound of Greek myth that guards the entrance to the underworld — fawning on the dead who arrive, savage to any who would leave.
Cerberus is the monstrous dog of Greek myth set to guard the gates of the underworld, the realm of Hades. His task is not to keep the living out but to keep the dead in: the sources describe him fawning on those who enter and turning savage on anyone who tries to leave. He is one of the brood of Typhon and Echidna, the same line that produced the Hydra and the Chimera — the monsters at the edge of the ordered world.
The number of his heads was never fixed. The early poet Hesiod gives him fifty; later writers, and almost all the art, settle on three, often with a mane or tail of writhing serpents. The disagreement is itself characteristic of Greek myth, which had no single authority and tolerated variants that flatly contradicted one another. What stays constant across the versions is the function: a threshold guardian, the embodied difficulty of the boundary between the living and the dead.
The story most often told is his capture. The last and hardest of the twelve labours imposed on Heracles was to descend to the underworld and bring Cerberus up alive — and, in most tellings, to do it without weapons, mastering the creature by main strength before returning it below. The descent of a living hero into the land of the dead and his return is one of the oldest patterns in the literature; Cerberus is the obstacle that makes the crossing a feat. He guards a door that, by the logic of the myth, is supposed to open only one way.
The Greeks did not, on the available evidence, worship Cerberus; he is a figure of story and image rather than of cult. Later readers nonetheless found him useful to think with. Allegorising commentators in antiquity and after took the underworld hound as a figure for the grave, or for the appetites that devour, or simply for death’s refusal to give back what it has taken — readings that say more about the interpreters than about anything the early poets meant. The plainer point survives all of them. Cerberus is the shape Greek imagination gave to the threshold no one was meant to recross: a guardian at a door, recognisable at once, and easier to picture than to pass.