ThunderCats

With their home planet, Thundera, about to explode, the Thunderians flee to a distant galaxy. Before they can make the long journey the Mutants sweep in and destroy most of the fleet in an attempt to capture the Eye of Thundera. Due to the attack, the Thundercats find themselves on a distant planet. A grown-up Lion-O must save his Thundercats from the Mutants on Third Earth.

The Mutants, who have also reached Third Earth, encounter an old pyramid. It turns out to be the home of Mumm-Ra the Ever-Living, and they join forces to capture the Sword of Omens. Both the Mutants and Mumm-Ra attempt to attack Lion-O to possess the Sword, but miserably fail.

The Ro-Bear Berbils are a friendly group of robot bears that live on Third Earth. Lion-O and Snarf don't know this, and end up getting caught in a Ro-Bear trap. The Berbils free them however, and they form an alliance. Mumm-ra attacks the Berbil village, but the Thundercats save it. In return, the Ro-Bears help the Thundercats to build Cats' Lair, a new base for the Thundercats.

The homeless Mutants also make plans to build their home. They enslave a primitive race of beings called Brute-Men to do their work for them. The Thundercats go to Castle Plunn-Darr to free the Brute-Men from the Mutants.

Mumm-Ra uses his shapeshifting abilities to pass himself off as a Thunderian so he can stage the "rescue" of Cheetara and infiltrate Cats' Lair.

When Snarf and a young unicorn are captured by the pirate Hammerhand and his crew of Berserkers, Lion-O goes to rescue them.

Recurring nightmares of Thunderians killed on Thundera as he fled to safety with Jaga and the other ThunderCats awaken Lion-O. Jaga comes to tell him that they in fact survived and are living on Third Earth. After meeting with the other ThunderCats, they decide to begin searching for them but Mumm-Ra has plans as well.

Lion-O's rescue attempt fails and the captured Thunderians are taken to Fire Rock Mountain after another failed attempt on their part to break free from their captors.

Lion-O loses the Sword of Omens in an avalanche. Panthro battles the Fist-Pounder with the ThunderTank. The Mutants arrive at Fire Rock Mountain to take control of the prisoners.

The Thunderians attempt to escape their prison. Lion-O arrives at Fire Roc Mountain and is confronted by Hachiman who believes Lion-O is causing the suffering of his ancestor.

Lion-O and Hachiman are reconciled and the ThunderCats close in on rescuing the Thunderians from Fire Rock Mountain. But they'll need supernatural help if they are to pass through the Thundranium gasses to reach them.

Mumm-Ra plays deception with the Thundercats when he (disguised as Jaga) tells Lion-O that the Thundercats at the Tower of Omens will rebel and take Third Earth for themselves. Then he disguises himself as a Tuska warrior and asks the Thundercats at the tower for help. Ben-Gali, Pumyra, and Snarfer go to investigate while Lynx-O calls on the others to help, but Lion-O warns the others of their possible treachery, but Panthro, Cheetara, and Snarf go anyway but somewhat cautious. When they meet, the Tuska warrior "accidentally" causes the newer Thundercats to attack. He then disappears and the Thundercats start fighting each other. Meanwhile the Lunataks invade Cats Lair and the Tower of Omens. Lion-O must call on the Thundercats hoping they'll stop fighting each other to defeat the Lunataks and Mumm-Ra, which they do.

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 preparing the Feliner for the trip to New Thundera. Vultureman notices that the tower is only guarded by 3 Thundercats and goes to Sky Tomb and tells Luna. Luna then sends Red Eye and Tug Mug to attack the Tower, and they capture Lynx-O and the Thunderkittens.

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 Thundercats plan, so he abandons the other Mutants and takes the Rat-Star. But Slithe has snuck aboard. Right after the Feliner takes off, the Rat-star ambushes them and it seems all over for the Thundercats aboard the Feliner. Lion-O uses the sword to free everyone and along with Ben-Gali and Wilykit on the HoverCat, go after the Ratstar and it crashes on Hook Mt. The Thundercats leave Third Earth's atmosphere and Lynx-O tells him that Mumm-Ra has already located the Sword of Plundarr.

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 defeats the Thundercats with the Sword of Plundarr. Now Mumm-Ra possesses the Sword of Plundarr and the Treasure of Thundera

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, Cheetara, Tygra, Snarf, and Snarfer are changed into Thundercubs. Lion-O must use the sword to give the Thundercubs Thundercat understanding. Meanwhile on Third Earth, Jackalman, Monkian, and the Lunataks attack Cats Lair and capture Ben-Gali and Wilykit. Lion-O learns that the Thundercats back on Third Earth are being held prisoner in Sky Tomb, so he decides to send the Thundercubs to Third Earth to rescue them while he tries to get the Book of Omens from Mumm-Ra. Snarf decides to stay with Lion-O an

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, they are all cornered by the Lunataks, but Lion-O and Snarf arrive to save the day. The Thundercubs must then go in the Cave of Time to become Thundercats again and Mumm-Ra is abandoned on New Thundera and the Ancient Spirits bring him back to Third Earth.

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 made by the device. The Hovercat crashes in the swamp, and Lion-O gets intoxicated by the deadly swamp water. Jaga appears and tells Snarfer that he must get the Totem of Dera to heal Lion-O. Snarfer gets the Totem and succeeds in healing Lion-O. Lion-O calls on the T-cats to try to kill the swamp monster. When all their weapons prove ineffective against the monster, the T-Cats come up with the idea to dissolve the monster in water and they succeed in defeating it.

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 Cat's Lair and the Tower of Omens. The Thundercats soon arrive and begin plans to build a new lair. Mumm-Ra meanwhile learns that the planet's gravity is controled by the Gyroscope under the Churning Rocks at the center of the planet. The Gyroscope is guarded by Jaguara, an ancient Thundercat sorceress. Mumm-Ra disguises himself as Jaga and puts Jaguara under a spell, making her change the rotation of the Gyroscope to throw the Thundercats clear off the planet. As the Thundercats are floating away, Lion-O calls on the Eye of Thundera to help him, and it breaks Mumm-Ra's spell... but not before Mumm-Ra takes part of the Gyroscope's regulator. Without those controls, the planet will be destroyed within 2 hours...

More and more earthquakes are ocurring because of the malfunctioning Gyroscope. Meanwhile Lion-O recieves a distress signal from Thunderian refugees, and he, Cheetara, and Snarf go to find them. Mumm-Ra resurrects Grune the Destroyer, and Grune seeks out Lion-O and Cheetara. Grune finds and fights them, breaks the Sword of Omens, and then he chains them up on the Churning Rocks. Snarf, who was hiding, gathers the pieces of the Sword to take back to Bengali to be fixed. Snarf gets captured by Char, a theif who wants the Sword for himself. Snarf tricks him into reforging the Sword, and when it is as good as new, Lion-O begins to sense it, and so he calls it. The Sword goes to him, he escapes, and then he defeats Grune. But Mumm-Ra still has the Gyroscope's regulator...

Lion-O, Panthro, and the Thunderkittens take the Whisker, a new flying vehicle, to the Churning Rocks to rescue the Thunderian refugees who had called from there. The Thundercats get captured by Two-Time, a robot with 2 heads. Two-Time takes them aboard his spaceship, Dome-Down, and the Thundercats see that he has also captured the refugees. Lion-O defeats Two-Time and the refugees are freed. Meanwhile, Lynx-O, Cheetara, and Bengali spot Mumm-Ra near the Churning Rocks, and inform Lion-O of this. Lion-O, Panthro, and the Thundekittens head to the Churning Rocks and confront Mumm-Ra, who is in the form of Jaga again. They break Mumm-Ra's spell (again) over Jaguara, who had temporarily repaired the Gyroscope. Lion-O defeats Mumm-Ra, but Mumm-Ra reminds them all that eventually the planet will be destroyed without the real controls, which he still has...

Mumm-Ra sends Ma-Mutt disguised as Mandora to free the Mutants from Capt. Bragg's circus train and sends Bragg and Crowman falling into deep space. The Mutants are then ordered by Mumm-Ra to get rid of Tygra and Pumyra. The Mutants attack Snowman on Hook Mt. and Snowmeyow gets Pumyra for help and Tygra contacts the real Mandora to save Bragg and Crowman. Then together, they recapture the Mutants. Meanwhile on New Thundera, the earthquake tremors grow worse and the new Cats Lair collapses trapping Snarf in the ruins. Lion-O uses the sword to contact the other Thundercats and they rush to the Lair to save Snarf. Afterwards, Mumm-Ra destroys the Gyroscope's regulator...

After another earthquake caused by Mumm-Ra ruins the new Cats Lair construction site, the Thundercats go to see Jaguara and confront Mumm-Ra. Unfortunately, Mumm-Ra puts up a force field over entrance. Jaga appears to Lion-O and tells him to use the Eye of Thundera to get to Jaguara and the Gyroscope. Lion-O does so and battles Mumm-Ra, who throws him into the bottomless pit underneath the Gyroscope. Lion-O however, manages to throw his grappling hook to the top, which pulls him back up. Lion-O then shines the signal, which goes through the force field. All the Thundercats leap through the signal which takes them through the force field. Together, they fire all their weapons at Mumm-Ra and he is defeated. But before he leaves, he breaks the cord that holds the Gyroscope above the pit and it falls through. Now, New Thundera is literally falling apart. But Lion-O throws the sword in the spot where the Gyroscope used to be and calls upon the Thundercat Ancestors for help. The sword starts

The Ancient Spirits of Evil bring the Mirror Wraith to Mumm-Ra, and he disguises it as a child's toy. Mumm-Ra then intercepts a thunderian escape pod which carries in it a little girl. He gives the toy to the child (Leah), and leaves. She is rescued by the Thundercats, and goes into New Cat's Lair with the doll. The doll turns into the Mirror Wraith when left alone, and begins to destroy Cat's Lair, and the Thundercats have no clue where the evil Mirror Wraith came from.