• Air date: 05 Sep '88 20 episodes
      The inhabitants of the planet Thundera evacuate just before it is destroyed. They were pursued by a band of mutants. All but one of their escape ships was destroyed. Only a small group of Thunderans (Thundercats) remained. With only half engine power, the group, which was led by Jaga, had to set a course for the nearest planet. Jaga commanded their ship while the other seven were in their stasis tubes. Jaga died on their journey to Third Earth and their ship crashed there. Soon they made friends with various groups in the area and they designed a fortress. Mumm-Ra the centuries-old embodiment of evil, along with the mutants that destroyed the rest of the Thunderans are a constant threat. But Lion-O, the new leader of the Thundercats, with his weapon the "Sword of Omens" will help the Thundercats to have a standing chance.
  • List of Episodes (20)
    • 1. ThunderCubs (1)

      05 Sep '88
      Mumm-Ra learns about the Treasure of Thundera and the Sword of Plundarr (Jaga had beaten Ratilla, who owned the Sword, and then buried the sword deep underground), and he and Ma-Mutt ""travel back in time and space"" to explore the debris of Thundera and look for the sword, which causes the planet to reform. The Thundercats find out about this and must make the journey to New Thundera to stop Mumm-Ra. Lynx-O and the Thunderkittens are left at the tower while the other Thundercats at the Lair are
    • 2. ThunderCubs (2)

      06 Sep '88
      Lion-O and the other Thundercats arrive and save Lynx-o and the Thunderkittens from Red Eye and Tug Mug. The Thundercats learn more about New Thundera, especially the dangerous places affected by the moons of Plundarr where the Lunataks come from. The Thundercats must develop special equipment and clothing to counter those dangers. Also, they learn that all the snarfs have been turned into slaves and Snarf and Snarfer want to rescue them no matter what the cost. Vultureman learns of the
    • 3. ThunderCubs (3)

      07 Sep '88
      Mumm-Ra retrieves the Sword of Plundarr and the Thundercats arrive on New Thundera. While the Thundercats want to get the Sword and treasure, Snarf and Snarfer want to free their fellow snarfs. While the Thundercats sleep, Snarf and Snarfer sneak away, but are discovered and captured by Mumm-Ra. He disguises himself as Snarfer and he leads the Thundercats to where the treasure is located, but it can only be freed by the Sword of Omens. Once the treasure is freed, Mumm-Ra reveals himself and
    • 4. ThunderCubs (4)

      08 Sep '88
      Mumm-Ra tries to get away but the Sword of Omens breaks open the casket dropping the treasure all over the planet, and Snarf, Snarfer, and one other snarf escape. Mumm-Ra gives a false Book of Omens to Ma-Mutt, Slithe and Vultureman, who have arrived on New Thundera in the Rat-star, for safe keeping so that he can decipher the real Book of Omens. The Thundercats go after them through the Caverns of Cold. They head toward the Canyons of Youth, but due to the effects of the canyon, Panthro,
    • 5. ThunderCubs (5)

      09 Sep '88
      Lion-O frees the Thundercubs from Mumm-Ra's spell and the Thundercubs safely leave New Thundera. Lion-O and Snarf must confront Mumm-Ra and get the Book of Omens. After they defeat Mumm-Ra, they ask Mu-Mutt (using a magical flute) to use Mumm-Ra's ""device"" to get them back to Third Earth. Meanwhile the Lunataks capture some Berbils and the Thundercubs return to Third Earth and they and the Thunderkittens must go to Sky Tomb to free the other Thundercats and the Berbils. After everyone is freed
    • 6. Totem of Dera

      12 Sep '88
      Mumm-ra finds the Totem of Dera (a part of the T-cat treasure) which has special healing powers and can bring inanimate objects to life. He gives it to Vulture-Man and the Mutants so they can make a device to destroy the T-cats. After making the device, the mutants decide to test it near a swamp. At Cat's Lair, Lion-O sees that there is some mutant activity near the swamp. He, Wilykit, and Snarfer decide to check it out. When going to the swamp, the Hovercat is brought down by a swamp monster
    • 7. The Chain of Loyalty

      13 Sep '88
      After looking at the Book of Omens, and seeing a picture of a necklace, Lion-O discovers that there are pictures of the Thundercats on the necklace. Jaga appears to Lion-O and tells him that he is looking at a picture of the Chain of Loyalty. Jaga tells Lion-O that if the chain gets broken, it would cause the Thundercats to turn against each other. In hearing this, Lion-O and the Thundercats (Panthro, Tygra, Cheetara, and the Thunderkittens) set off to Thundera to find the chain. Mumm-ra,
    • 8. Crystal Canyon

      14 Sep '88
      Lion-O, Lynx-O, Snarf and Tygra go to the Crystal Canyon, thinking the Lunataks somehow got the Treasure of Thundera. While there, they encounter Aluro and Chilla. The two Lunataks trick the Thundercats by confusing them using with their reflections. They knock out the Thunderstrike and cause it to crash. Lynx-O is seriously injured and Lion-O is knocked unconscious. Tygra and Snarf find the Keystone and when Tygra holds the Keystone, he becomes convinced that it is making him more powerful. He
    • 9. The Telepathy Beam

      15 Sep '88
      Vultureman creates a device that plays around with Cheetara's sixth sense. She begins to see images that aren't real, and she soon begins to lose faith in herself. Meanwhile, the Lunataks enslave Panthro with a mind control device, and tell him to make the Sky-Tomb able to fly to Thundera. When the Thundercats are looking for Panthro, Vultureman makes Cheetara see images of him being captured by Mumm-Ra, being stuck on Hook Mt., and being held at Castle Plundarr. Lion-O goes to Mumm-Ra's pyramid
    • 10. Exile Isle

      16 Sep '88
      The Thundercats capture the Lunataks and, tired of dealing with their evil ways, decide to exile the Lunataks to Exile Isle, an island in space far away from Third Earth. When the Lunataks arrive, they meet up with Captain Cracker, a pirate who the Thundercats also exiled. Together, the Lunataks and Capt. Cracker send out a distress signal to a passing ship. When the ship comes near the island, the Lunataks send up a cloud of fog, which makes the ship crash. They use the engines of the ship to
    • 11. Key to Thundera

      19 Sep '88
      While trying to figure out a way to read the Book of Omens, Lion-O tries looking through the sword at the book. He is immediately drawn into the book, where a voice asks him if he has ""the key."" Lion-O says he doesn't, and four dragon heads appear and shoot fire at him. Snarf, who saw Lion-O get sucked into the book, tries to show Cheetara what happened, and he too gets sucked in. Mumm-Ra, who also watched Lion-O get sucked in, goes to cats lair and takes the book so he can destroy it with
    • 12. Return of the ThunderCubs

      20 Sep '88
      Panthro, Tygra, and Cheetara return to New Thundera in the Feliner to find more of the Treasure of Thundera, but Mumm-Ra shoots the Feliner down and, as the Fog of Despair, sends them to the Canyons of Youth, which changes them back into Thundercubs. Then Mumm-Ra disguises himself as Lion-O and tells the Thundercubs to find the treasure for him. Meanwhile, back on Third Earth, Lion-O and Snarf decide to go rescue the Thundercats on New Thundera, but they must ask the Mutants to take them to New
    • 13. The Formula

      21 Sep '88
      Aluro invents a ""booster"" potion in hopes that it can make Sky Tomb able to fly to Thundera. It doesn't work, and he throws the potion into the forest. Then he notices everything in the forest has grown huge. He and Luna give the potion to the Mutants, who sprinkle it around Cats Lair. The Mutants also capture Lynx-O and Snarf. But while the Mutants are preparing to transfer Lynx-O and Snarf from their cell, a mouse in the cell who Snarf had befriended gets some of the potion and attacks the
    • 14. Locket of Lies

      22 Sep '88
      On Thundera, Mumm-Ra creates the Locket of Lies and has Mu-Mutt plant it in the Valley of the Snarfs. Eggbert and Oswald Snarf find the locket and contact the Thundercats about it. When communications break up, the Thundercats (Lion-O, Cheetara, Panthro, Tygra) go to Thundera to see the Locket. When they arrive, the Locket leads them to a place in front of an old building. But the ground they are standing on gives way and they are trapped in a well. Mumm-Ra shows up and tells them not to try to
    • 15. Bracelet of Power

      23 Sep '88
      Tygra, Cheetara, and Bengali bring back a few more pieces of the Treasure of Thundera. Snarf is fascinated by a bracelet and takes it to wear around. He sees that everyone obeys his every command when he has on the bracelet. Mumm-Ra also notices this. He goes to Cats Lair, takes the bracelet, and turns Lion-O, Cheetara, Tygra, and Panthro into his slaves. He takes them to his pyramid and locks them in a cell. Snarf and the Thunderkittens decide to go rescue the Thundercats. At the pyramid, when
    • 16. The Wild Workout

      26 Sep '88
      Lion-O, Panthro, and Snarf set out to look for more pieces of the Treasure of Thundera, and Mumm-Ra sets a trap for them. He freezes them in the caverns of cold on Thundera. Meanwhile, back on third earth, the Luna-tacs, in need of another source of power for their ship, use exercise machines to power it up. They capture the other Thundercats and force them to workout on the machines to power up the ship. The Thundercats manage to overwork the power supply, and escape from Sky Tomb. Back in the
    • 17. The Thunderscope

      27 Sep '88
      Back visiting their old wreckage site, Lion-O and Snarf stumble upon the Thunder-scope, a legendary thunderian telescope that locates lost thunderians, and their belongings. Mumm-Ra, interested in the Thunder-scope so he could find the treasure of thundera, ambushes Lion-O. He actually kills him in this scene. Before Lion-O dies, he manages to take out a lens from the Thunder-scope so Mumm-Ra could not completely use it. Jaga appears to Snarf, and Lion-O's dead body, and revives him. Mumm-Ra
    • 18. The Jade Dragon

      28 Sep '88
      Mumm-Ra discovers the power of one of the pieces of the treasure of Thundera. The Double-Headed Dragon of Doom, or the Jade Dragon possess the power to entrap people in its stomach. The legend says that Haji-Man's ancestor gave the dragon to his wife as a marriage gift, and since her father was so against their marriage, he put a curse on the dragon and it engulfed Haji-man's ancestor. Jaga freed the him, and he gave the dragon to Jaga for safe keeping. Now, the Thundercats have found the Jade
    • 19. The Circus Train

      29 Sep '88
      A bounty hunter known as Captain Bragg comes to Third Earth to help the Thundercats get rid of the Mutants and the Lunatacks. Capt Bragg tricks Wilykat in going with him and they first go after the Mutants. After capturing them, they go to capture the Lunataks. They capture all except Luna and Amuk, who free the other Lunataks, put Bragg in a cage and tie Wilykat to the train's engine. Lion-O and Wilykit arrive to save Wilykat and the Lunataks are defeated. All the Mutants and all the Lunataks
    • 20. The Last Day

      30 Sep '88
      With the Mutants and Lunataks gone, the Ancient Spirits of Evil give Mumm-Ra until sunset to destroy all the Thundercats, and to prove they're not bluffing, they exile Ma-Mutt. Mumm-Ra spreads destruction all over Third Earth, sends Tygra, Cheetara, and Panthro to limbo, and buries Lion-O alive. Then he attacks and destroys the Tower of Omens, and the Thunderkittens barely escape, but Mumm-Ra sends them to limbo too. Snarf must go into the Book of Omens to find out how to defeat Mumm-Ra. Jaga