Eurytus and Cteatus

Eurytus and Cteatus were twin brothers in Greek Mythology. Named the Moliones or Molionidai for their mother, Molione, they were the sons of either Actor or Poseidon and nephew of Augeas. Greek legend maintains that the brothers were born conjoined with only one body but two heads, four arms and four legs, though Homer makes no mention of this.

Both brothers went on expeditions of war to the Neleus and the Pylians, and later led an army marching against their uncle Augeas at the behest of Heracles. However after the latter made peace, the brothers attacked Heracles and were subsequently killed by him outside Cleonae.

Eurytus and Cteates married the twin daughters of Dexamenus, Theraephone and Therenice, respectively. Their respective sons, Thalpius and Amphimachus, were counted among the Achaean leaders in the Trojan War.

...
Wikipedia