In Greek mythology , the youngest son of Gaea and Tartarus .
A grisly monster with a hundred dragons' heads, he was conquered and cast into the underworld by Zeus but continued to be the source of destructive winds. In other accounts, he was confined in the land of the Arimi in Cilicia or under Mount Etna , where he caused eruptions and was thus the personification of volcanic forces. Among his children were Cerberus , Chimera , and the multiheaded Hydra. Later writers identified him with the Egyptian god Seth .