ThunderCats 1985 Season 4 Episode 1 Return to Thundera Episode I Episode Title:Return to Thundera Episode I.Episode Description:The Ancient Spirits of Evil give new life to Mumm-Ra and Ma-Mutt, send them to New Thundera, and build a new Pyramid for Mumm-Ra. The ThunderCats say goodbye to Third Earth and depart for Thundera, leaving Tygra and Pumyra behind to watch the Tower of Omens and Cats' Lair. The ThunderCats soon arrive and begin plans to build a new lair. Mumm-Ra, meanwhile, learns that the planet's gravity is controlled by the Gyroscope under the Churning Rocks at the center of the planet. He tries to use this knowledge to destroy the ThunderCats and trick the Gyroscope's guardian, the ancient sorceress Jaguara.