On pg. 202 of D’Ooge’s book.
THE FLESH-EATING HORSES OF DIOMEDES
After he arrived home from the island of Crete, Hercules was sent to Thrace by Eurystheus. There, a certain Diomedes, (who was) a very fierce man, possessed a kingdom and he kept everyone off from his territory. Hercules had been ordered to take Diomedes’ horses and to lead (them) to Eurystheus. However, these horses devoured the most wretched men on whom the king desired to inflict punishment. When Hercules arrived, first, he demanded for the horses from the king, but the king refused to give them up. Then, being roused with anger, he killed the king and handed his body over to the horses. And so, he who previously had killed many (men), he himself was killed by the same punishment. And the horses, (having) recently (been) very savage animals, had become tamed after they devoured their master’s body.