The Cyclopes were gigantic, one-eyed monsters. Probably the most famous of them is Polypheus, the Cyclops that was blinded by Odysseus.
Based on their description, they were a wild race of gigantic growth, similar in nature to the earth-born Giants, and had a single eye in the middle of their foreheads. They led a lawless life, possessing neither social manners nor fear for the gods, and were the workmen of Hephaestus, whose workshop was supposed to be in the heart of the volcanic mountain Etna.
