#1 - The Trouble with ThunderKittens 8.38
Season 1 - Episode 62
The Thunderkittens steal the Thundercats' weapons so they can prove they can use them, but the Mutants steal the weapons! Lion-O and the kittens must get the weapons back from the Mutants.
#2 - Fond Memories 8.22
Season 1 - Episode 65
Mumm-Ra pretending to be one of the ThunderCats friends takes Lion-O to a gallery of the ThunderCats accomplishments. However, the pictures can come to life and Lion-O must battle Rataro, Safari Joe, and others. ONce the other ThunderCats arrive they end up in trouble and Lion-O is confronted by Mumm-Ra who has made himself into a carbon copy of Lion-O. It's Lion-O VS Lion-O and is a draw, until Lion-O shows Mumm-Ra his reflection.
#3 - Berbils 8.10
Season 1 - Episode 3
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.
#4 - Return to Thundera (2)
Season 4 - Episode 2
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...
#5 - Exodus 8.05
Season 1 - Episode 1
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.
#6 - ThunderCubs (3)
Season 3 - Episode 3
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
#7 - The Slaves of Castle Plun-Darr
Season 1 - Episode 4
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.
#8 - ThunderCubs (4)
Season 3 - Episode 4
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
#9 - ThunderCubs (2)
Season 3 - Episode 2
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.
#10 - Mumm-Ra Lives (5)
Season 2 - Episode 5
Lion-O, Panthro, Tygra, and Pumyra set out to Darkside to free the slaves the Luna-tacks have imprisoned. In doing so, they get captured. Cheetara and Lynxo set out to Sky Tomb to save them. The Thundercats see Mumm-Ra for the first after his ""death"" time at Sky Tomb, and discover that he cannot be harmed by his own reflection anymore. The ancient spirits of evil have made him more powerful when they revived him. They Thundercats manage to escape, and leave the Luna-tacks fighting amongst themselves.
#11 - The Terror of Hammerhand
Season 1 - Episode 6
When Snarf and a young unicorn are captured by the pirate Hammerhand and his crew of Berserkers, Lion-O goes to rescue them.
#12 - Leah
Season 4 - Episode 6
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.
#13 - Psych Out
Season 2 - Episode 7
Mumm-Ra tells Aluro that the Egora Talisman will give whoever possesses it the power of extreme self-confidence. Aluro finds the talisman and uses it, along with his own powers of hypnotism, to "take away" the Thundercats' self-confidence, leaving them hopeless and confused. Only Snarf remains and it is up to him to defeat Aluro and restore the Thundercats.
#14 - Frogman
Season 4 - Episode 7
Wily Kit and Kat are constructing a well for the New Cat's Lair on New Thundera. The Thundercats on New Thundera receive a distress signal from Thunderian refugees trying to find their way to New Thundera. The Kittens are left alone with Snarf on at the New Cat's Lair, and Lion-O and Snarfer are out constructing an early warning device (I guess for weather purposes). The rest of the Thundercats seek out the refugees in space. When Wily Kit and Kat strike water, they accidentally unleash a monster that Jaga trapped in the underground lake centuries ago. Frogman, with aquatic powers, tries to sink the New Cats Lair. Lion-O however re-traps Frogman in his watery prison.
#15 - The Mask of Gorgon
Season 2 - Episode 8
Mumm-Ra plans on using the legendary Mask of Gargon to free a sleeping child in the hills of Elfshima to use against the Thundercats. When Chilla and Tug Mug fail to get the mask because it turned them to stone, Mumm-Ra summons it and decides he needs the Eye of Thundera so that the mask can use sight beyond sight to awaken the giant child. Lynx-O warns the Thundercats of the mask and the sleeping child, but Lion-O, Panthro, and Willa still go to the pyramid, but are turned to stone by the mask. Mumm-Ra then uses the Eye of Thundera and the mask to awaken the giant. But Lynx-O and Ben-Gali in the Thunderstrike defeat the giant and the mask gets smashed apart restoring everyone who had been turned to stone, and the Eye of Thundera burns the book that contained the mask's terrible secrets.
#16 - ThunderCubs (5)
Season 3 - Episode 5
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.
#17 - The Garden of Delights
Season 1 - Episode 9
While investigating an earthquake, Tygra stumbles across the Garden of Delights and meets a talking plant named Silky, who offers him her fruit. But it turns out that "Silky" is another of Mumm-Ra's disguises and eating the fruit seems to have affected Tygra's mind.
#18 - The Telepathy Beam
Season 3 - Episode 9
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, and is ambushed by Luna and Amok, who capture him. Tygra goes to Plundarr and is captured by Red Eye. The Thunderkittens also get captured on Hook Mountain. Cheetara is about to go crazy, but Lynx-O tells her to listen to her heart instead of her mind. She turns into a huge ball of energy that shoots out and destroys Vultureman's device and frees Panthro and the other Thundercats.
#19 - Mandora: The Evil Chaser
Season 1 - Episode 10
Lion-O and Snarf stumble upon a portable jail cell, and mistakenly open it up. Three of the galaxy's worst villains escape. One of them, a slick thief, manages to steal Lion-O's sword. Lion-O helps Mandora, the inter-stellar police officer that imprisoned the villains, recapture them, and return them to their cells.
#20 - The Unholy Alliance
Season 1 - Episode 2
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.
#21 - The Ghost Warrior
Season 1 - Episode 11
Two Bolkins (sheep-like beings from Third Earth) unleash the ghost of Grune the Destroyer, a renegade Thundercat who once terrorised Third Earth and now turns his attention to the Thundercats.
#22 - Helpless Laughter
Season 4 - Episode 11
A convergence of the Moons of Plun-Darr causes a drought on Thundera. Panthro and Snarf go looking for water, then Ezuka, the flying Serpent of Dreary Canal wanting to get water itself, attacks Panthro and Snarf and causes them to fall into the Swamp of the Laughing Lilypads, making them laugh out of control. Ezuka attacks the Lair, still looking for water. Lion-O uses the Sword to make some rain, then he and Ben-Gali use the Thunderstrike to melt some ice, but Mumm-Ra comes along and causes a flood. Lion-O calls for the others, which also free Panthro and Snarf from the laughter and they use some of the Swamps water to cause Mumm-Ra to laugh uncontrolably, and he falls in the flood waters and is washed away.
#23 - Time Switch
Season 2 - Episode 12
While burying one of the time capsules that transported the Thundercats to Third Earth, it smashes apart and Lion-O gets caught in its gases, making him younger and younger by the minute. The other Thundercats must find a way to reverse the process and realize the Cave of Time is the only way, but they must get Lion-O there before he "vanishes" from existence. Things get worse when the young Lion-O and Snarf are captured by the Lunataks.
#24 - Return of the ThunderCubs
Season 3 - Episode 12
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 Thundera in the Rat-Star. The Mutants agree, secretly planning to attack Lion-O once they're in space. They do attack and imprison him and Snarf on the way to Thundera, but they manage to break out. Cheetara meanwhile, using her sixth sense, locates part of the treasure, the Mirror of Truth. The real Lion-O shows up, and uses the Sword of Omens with the Mirror of Truth to restore the cubs to their proper age, and Mumm-Ra reveals himself and turns into Mumm-Ra the everliving. Cheetara uses the mi
#25 - Malcar
Season 4 - Episode 10
Mumm-Ra summons Malcar, an ancient alchemist, to return from the dead. The alchemist returns old and weak, as he was when he died. Mumm-Ra takes him to the forest of youth to restore his youth and power. Malcar regains his powers, and uses them against the Thundercats. He transforms all the Thunderillium on the planet into Thundrainium.