Air date: 1/23/85

The Thundercats must find a new home after their home planet, Thundera, explodes. Their journey changes when an enemy known as the Mutants attack and leaves their ship severely crippled. And a young boy must learn what it means to become a man and Lord of the Thundercats as he learns to wield the power of the Sword of Omens.

The Unholy Alliance

Air date: 1/23/85

While exploring Third Earth, the Mutants ship is brought down by a mysterious black pyramid which is the home to Mumm-Ra, an evil demon who is willing to form an allegiance to capture the Eye of Thundera. With the young Lord of the Thundercats in sight, Lion-O is about to face his toughest enemy yet.

Berbils

Air date: 9/11/85

While out exploring, Lion-O and Snarf are taken prisoner by a band of small robotic bears named Ro-Bear Berbils. They soon learn that the Berbils are being frequently attacked by the Trolligs who steal their fruit to give to the Giantorrs.

The Slaves of Castle Plun-Darr

Air date: 9/12/85

Cats Lair is nearly complete when an agitated Wilykit and Wilykat rush home to tell the other ThunderCats that the Mutants have enslaved a race of creatures called Brute Men to build their new fortress. Tygra tells the twins to stay behind as the adult ThunderCats rush off to free these peaceful creatures.

Plumm-Ra

Air date: 9/13/85

Mumm-Ra disguises himself as a Thunderian and claims to have rescued Cheetara from the mutants.

The Terror of Hammerhand

Air date: 9/16/85

Snarf frees a unicorn from mechanized Viking berserkers who are out hunting for food.