Somewhere out in deep space - and out of the creative imagination of the animation aces of Hanna-Barbera Studios - live the Herculoids. Humanoid Zandor, along with his wife Tara and son Dorno, lead a group of unique creatures: Zok the flying dragon, powerful simian Igoo (who possesses rock-like skin), rhinoceros hybrid Tundro, and two protoplasmic wonders appropriately named Gloop and Gleep. Together, they use their diverse super strengths to defend their utopian planet against attack from such sinister invaders as the Pod Creatures, the Reptons, and the Mutoids.