Surnamed the "All-seeing," a fabulous creature with a hundred eyes, of which one half was always awake, appointed by Hera to watch over Io, but Hermes killed him after lulling him to sleep by the sound of his flute, whereupon Hera transferred his eyes to the tail of the peacock, her favourite bird. Also the dog of Ulysses, immortalised by Homer; he was the only creature that recognised Ulysses under his rags on his return to Ithaca after twenty years' absence, under such excitement, however, that immediately after he dropped down dead.