In the Twelve Labors of Hercules, Hercules killed Eurytion, the herdsman guarding Geryon’s cattle.
The tenth labor required Hercules to travel to the distant island of Erytheia and seize the red cattle owned by Geryon. The herd was protected by more than one figure: Eurytion served as its herdsman, while Orthrus, a two-headed dog, guarded it.
In the standard story, Hercules killed Orthrus first and then killed Eurytion before taking the cattle. He eventually confronted Geryon himself and defeated him as well. These supporting figures are why the labor includes several named opponents rather than a single monster.
Eurytion is easy to confuse with Eurytus, a different mythological king, and with Eurytion in other Greek legends. The herdsman’s name is specifically Eurytion in accounts of Geryon’s cattle.