Hercules and Xena – The Animated Movie: The Battle for Mount Olympus
The movie begins with the Sirens blaring Across The Sea of Time, a song about how Zeus took the Cronus stone from the Titans, had an affair with Alcmena, the wife of Amphitryon (stepfather of Heracles), and had a son named Hercules, who goes on to defeat a Lernaean Hydra at an early age and become a hero.