E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
or Achmon, and his brother Baslas were two Cercps for ever quarrelling. One day they saw Hercules asleep under a tree and insulted him, but Hercules tied them by their feet to his club and walked off with them, heads downwards, like a brace of hares. Everyone laughed at the sight, and it became a proverbial cry among the Greeks, when two men were seen quarrellingLook out for Melampygos! (i.e. Hercules).
Ne insidas in Melampygum.
According to Greek fable, monkeys are degraded men. The Cercps were changed into monkeys for attempting to deceive Zeus.