Cyclops are thought of as a race of savage one-eyed giants. In Greek mythology, the Cyclops Polyphemus was the son of Poseidon and captured Odysseus/Ulysses and his crew when they trespassed in his home so that they may receive a guest present. He was soon blinded by they when they stabbed his one eye with a large piece of wood ranging in between the size of a mast and a pole.
Generally, Cyclops have one giant eye centered in the middle of their face. Some depictions say that they also have a single horn on their heads while others say that they are simply giants with only one eye. There are also varying descriptions of them having both carnivorous and/or human-like teeth.
From mythology and the varying teeth theories, Cyclops would, under assumption, have a diet of sheep, cattle, humans, and/or plants.