Cyclops

In Greek mythology and later Roman mythology, a cyclops , is a member of a primordial race of giants, each with a single eye in the middle of its forehead. The classical plural is cyclopes , though the conventional plural cyclopses is also used in English. The name is widely thought to mean "circle-eyed".
Hesiod described one group of cyclopes and the epic poet Homer described another, though other accounts have also been written by the playwright Euripides, poet Theocritus and Roman epic poet Virgil. In Hesiod's Theogony, Zeus releases three Cyclopes, the sons of Uranus and Gaia, from the dark pit of Tartarus. They provide Zeus' thunderbolt, Hades' helmet of invisibility, and Poseidon's trident, and the gods use these weapons to defeat the Titans. In a famous episode of Homer's Odyssey, the hero Odysseus encounters the Cyclops Polyphemus, the son of Poseidon and a nereid , who lives with his fellow Cyclopes in a distant country. The connection between the two groups has been debated in antiquity and by modern scholars. It is upon Homer's account that Euripides and Virgil based their accounts of the mythical creatures.
In the Theogony by Hesiod, the Cyclopes – Arges, Brontes, and Steropes; were the primordial sons of Uranus and Gaia and brothers of the Hecatonchires. They were giants with a single eye in the middle of their forehead and a foul disposition. According to Hesiod, they were strong, stubborn, and "abrupt of emotion". Collectively they eventually became synonyms for brute strength and power, and their name was invoked in connection with massive masonry. They were often pictured at their forge. Uranus, fearing their strength, locked them in Tartarus. Cronus, another son of Uranus and Gaia, later freed the Cyclopes, along with the Hecatonchires, after he had overthrown Uranus. Cronus then placed them back in Tartarus, where they remained, guarded by the female dragon Campe, until freed by Zeus. They fashioned thunderbolts for Zeus to use as weapons, and helped him overthrow Cronus and the other Titans. The thunderbolts, which became Zeus's main weapons, were forged by all three Cyclopes, in that Arges added brightness, Brontes added thunder, and Steropes added lightning.
These Cyclopes also created Poseidon's trident, Artemis's bow and arrows of moonlight, Apollo's bow and arrows of sun rays, and Hades's helmet of darkness that was given to Perseus on his quest to kill Medusa. According to a hymn of Callimachus, they were Hephaestus' helpers at the forge. The Cyclopes were said to have built the "cyclopean" fortifications at Tiryns and Mycenae in the Peloponnese. The noises proceeding from the heart of volcanoes were attributed to their operations.
According to Alcestis, Apollo killed the Cyclopes, in retaliation for Asclepius's murder at the hands of Zeus. According to Euripides' play Alkestis, Apollo was then forced into the servitude of Admetus for one year. Zeus later returned Asclepius and the Cyclopes from Hades.