Lynne Lipton

Following up on a rumor, the ThunderCats take the Feliner to ThunDERa where supposedly a piece of the Treasure of ThunDERa lies within the Caverns of Cold. Mumm-Ra watches them in his cauldron and concocts a trap for them.

Vultureman hijacks a space bookmobile to escape Captain Bragg's Circus Train. On board, he learns of the powerful Rosencranz Medallion that once belonged to Mumm-Ra's arch rival Zaxx.

Amortus, an evil tentacled creature banished eons ago by the Thunderians, has returned to the new ThunDERa through Mumm-Ra's cauldron.

A rare lunar eclipse casts an eerie pale over the new ThunDERa. The eclipse opens a portal where the exiled Shadowmaster contacts the Ancient Spirits of Evil.

Mumm-Ra unveils his latest weapon, the Babylonian Barbarian Boiler, to destroy the ThunderCats. The Boiler emits a beam that rapidly melts anything it touches.

Tygra gets caught in a meteor shower while returning from Third Earth. Losing control of the Feliner, he crashes through the atmosphere into the unexplored Mosslands of New ThunDERa, where he awakens the gigantic Monster of the Mosslands.

An astronomical lineup of the five Thundarian moons causes a serious drought on the new ThunDERa. Panthro and Snarf take the ThunderTank to collect the remaining water of Dreary Canal. On the way, they are attacked and the ThunderTank crashes.

The tremors that previously threatens to destroy the new ThunDERa begin again when Jagara loses control of the gyroscope. The ThunderCats bring in a gyroscope specialist robot named Screw-Loose.

As reconstruction of the new ThunDERa continues, the ThunderKittens drill a water well, where they not only hit water but release an amphibian-like creature with green skin.

Mumm-Ra realizes he must destroy the new ThunDERa in order to destroy the ThunderCats, so he travels to the Great Beneath and blasts the gyroscope into rapid decay.

The ThunderCats are determined to stay on the new ThunDERa despite its unstable environment. Meanwhile, Mumm-Ra summons Grune the Destroyer to help him destroy the ThunderCats.

With Mumm-Ra banished form Third Earth, the ThunderCats return to their home planet ThunDERa. The Ancient Spirits decide to give Mumm-Ra one last chance to destroy the ThunderCats.