Orthrus was the two-headed hound — the lesser-known but no less monstrous brother of Cerberus — and one more of the great brood of monsters spawned by Typhon and Echidna. Where Cerberus guarded the gates of the dead, Orthrus guarded a herd of cattle at the edge of the world, and like so many monsters, his role in myth was to fall before the might of Heracles.
The Brother of Cerberus
A child of the monster-parents Typhon and Echidna, Orthrus was a fearsome dog with two heads (and, some say, a serpent for a tail). He was brother to Cerberus, the Hydra, the Chimera and the rest of that terrible family — a true monster of the bloodline that produced nearly every great beast the heroes faced.
The Guardian of the Red Cattle
Orthrus belonged to the three-bodied giant Geryon, who lived on the far western island of Erytheia and possessed a magnificent herd of red cattle. Orthrus, together with the herdsman Eurytion, guarded these cattle — and they were exactly what Heracles was sent to capture as the tenth of his Twelve Labours.
The Tenth Labour
When Heracles came for the cattle, Orthrus charged him — and the hero killed the two-headed hound with a single blow of his great club, before going on to slay the herdsman and then Geryon himself. Orthrus' death was swift, a stepping-stone in a greater labour, but it cemented his place among the monstrous family whose destruction defined Greek heroism.
The Shadow of His Brother
Orthrus is forever in the shadow of his more famous three-headed brother, yet he is significant precisely as part of that pattern: the monstrous brood of Typhon and Echidna, set as guardians and obstacles across the world, each in turn falling to a hero. He is also said, in some accounts, to be the father (with Echidna) of the Sphinx and the Nemean Lion — making this two-headed dog a link in the very chain of monsters.
Two heads were not enough to stop Heracles — few things ever were.