The cartoon features Hercules, the legendary hero, who dwells on Mount Olympus. Villains threaten the people of ancient Greece, often in the kingdom of Calydon, and Hercules comes to the rescue. When in serious danger, he puts on a magic ring which gives him superpowers. Once he puts the ring on and raises his fist, flashes of lightning (referred to as the Thunder of Zeus in several episodes) strike the ring, and Hercules is then endowed with super-strength. He does battle with such as Daedalus, an evil wizard who is the chief villain (sometimes accompanied by his pet cat Dydo). Other villains include Wilhelmine the Sea Witch (accompanied by her pet bird Elvira) and Murtis, who is invulnerable because he wears an iron helmet known as the Mask of Vulcan.