Orthrus

In Greek mythology, Orthrus (Ancient Greek: Ὄρθρος, Orthros) or Orthus (Ancient Greek: Ὄρθος, Orthos) was a two-headed dog who guarded the cattle of Geryon and was ultimately slain by Heracles, according to the mythographer Apollodorus. He was the offspring of the monsters Echidna and Typhon and the brother of Cerberus, another multi-headed guard dog.

The dog’s name appears in two forms in ancient sources: Hesiod, the earliest source, calls him “Orthus,” while Apollodorus refers to him as “Orthrus.” Hesiod also claims that Orthrus fathered both the Sphinx and the Nemean Lion, though it is unclear whether the mother was Echidna, the Chimera, or Ceto.

Orthrus, together with his master Eurytion, was tasked with guarding Geryon’s herd of red cattle on the island of Erytheia, located in the far west of the Mediterranean. During Heracles’ tenth labor, he killed Orthrus—using his club according to Apollodorus—and later slew Eurytion and Geryon before driving the cattle back to complete the labor. In artistic depictions, Orthrus is sometimes shown pierced by arrows rather than struck by a club.

The poet Pindar refers to the “hounds of Geryon” trembling before Heracles. His use of the plural may reflect Orthrus’ multiple heads or indicate a tradition in which Geryon had more than one dog.

Orthrus closely resembles Cerberus, the hound of Hades. Classical scholar Arthur Bernard Cook described Orthrus as Cerberus’ “doublet.” Like Orthrus, Cerberus was the child of Echidna and Typhon and often portrayed as multi-headed. Early accounts describe Cerberus as having fifty or even one hundred heads, though later literature standardized him with three. In art, Cerberus is sometimes shown with only two heads, and both dogs are occasionally depicted with snake-like tails. Both Orthrus and Cerberus served as formidable guardians and were overcome by Heracles as part of his heroic labors.