Fleeing the destruction of their home planet Thundera, Lion-O and the ThunderCats land on the world of Third Earth. But their enemies, the Mutants of Plun-Darr have followed them and it turns out Third Earth already has a Mumm-Ra problem.

Fleeing the destruction of their home planet Thundera, Lion-O and the ThunderCats land on the mysterious, dangerous, all-around awesome world of Third Earth! But their enemies, the Mutants of Plun-Darr have followed them and it turns out Third Earth already has a Mumm-Ra problem - can Lion-O learn the ropes of being a leader in time?

Lion-O has gotten ahold of the last jar of Thundersnaps - the best cookies Thundera had to offer! But a difficult to open cookie jar sends Lion-O and Cheetara chasing down the legend of Boggy Ben.

Lion-O wants to prove to the ThunderKittens that he's not just some boring old adult like Tygra, even if it means ignoring his instincts and messing with an obviously evil crystal.

Panthro becomes fed up with having to constantly fix things around the Cats' Lair, which proves to be a problem when an unstoppable drilling robot plans an attack.

A crying unicorn appears at the Cats' Lair and tells the ThunderCats that all of her unicorn friends have been captured; Tygra thinks he's just the unicorn expert to help the last of the unicorns.

Vultureman has got a brand new invention but there's one big problem: he stole the idea from Panthro! Oh, also Vultureman is using his invention to take over Third Earth. So, there are two big problems.

Third Earth is being overrun by super tough, super buff Warrior Maidens and it looks like the ThunderCats are next on their hit list! It's gonna be up to the ThunderKittens to save the day even though the kittens are so small and the Warrior Maidens are so big.

Barely escaping the sudden destruction of their home world, Thundera, Lion-O and the ThunderCats crash land on the mysterious and exotic planet of Third Earth, home to the evil Mumm-Ra and a bizarre host of other creatures and villains.

Barely escaping the sudden destruction of their home world, Thundera, Lion-O and the ThunderCats crash land on the mysterious and exotic planet of Third Earth, home to the evil Mumm-Ra and a bizarre host of other creatures and villains.

Feeling underappreciated by the other ThunderCats, Tygra starts hanging out with Mumm-Ra and cleaning his black pyramid. Whaaaat?

Cheetara is the fastest living being in the universe, until Monkian beats her in a race! Now Cheetara has to find something else to be the best at, while the rest of the ThunderCats find out how Monkian got so darn fast!

Lion-O "accidentally" releases a whole space prison-full of space criminals and winds up on the wrong side of the law. On the right side of the law is Mandora the Evil Chaser, a no nonsense space cop. Lion-O's gonna have to work real hard to prove he's not a criminal, just a little bit of an oaf.

Lion-O is tasked with mapping the beaches of Third Earth, which leads to him somehow draining the oceans of all water entirely. Woops. But a mysterious scientist with a robotic frog says they can fix everything by traveling under the earth, which is just the kinda crazy adventure Lion-O is all about.

Lion-O never pays attention during Tygra's training sessions so when he's asked to do a pop quiz on "sword magic" he accidentally opens a portal to the Astral Plane and releases the Nether Witch. The Witch imprisons Lion-O and Tygra in her nightmare realm and it's gonna take a lot of studying to figure out a way home. Wonder if the Astral Plane has any great teachers lying around.

Every time Mumm-Ra gets a hold of a magic artifact to restore his powers, the ThunderCats just smash it and turn him into a dinky skeleton again. Until today that is, because Mumm-Ra just remembered he's got the Ancient Spirits of Evil, and now he can get swole whenever he wants.

The Cats' Lair is attacked by gold-loving robot pirates, the Berserkers. This is a good thing, really, since it means Lion-O and the ThunderKittens can ditch their chores and fight robo-pirates instead. Just don't tell Tygra!!!

Freed from the Astral Plane, Jaga, ghost of the ThunderCats mentor, is now free to visit the Cats' Lair. Which means he can finally tell them why Thundera, their home world, exploded. It's story time.

While flying with his new invention, Panthro hits it off with a new friend, Barbastella, the Queen of the Bats. Now Panthro needs help getting ready for his big date with her, because it turns out Panthro is terrified of bats. Lion-O and Cheetara are happy to help but, wow, that is a lot to unpack.

After a battle with the Mutants, Jackalman gets confused and accidentally returns to the Cats' Lair with the Thundercats, he is the dumbest mutant. Jackalman pretends to be a Thundercat so his enemies won't catch him and the Thundercats pretend to play along because they feel bad for him.

The Thundercats are exhausted from fighting bad guys all the time so Lion-O suggests they spend a relaxing summer fun day at the beach, with no fighting. Unfortunately the beach is home to the Crabmen, giant, clawed humanoids that fight anyone who steps on their sand. Looks like summer fun day might involve some fighting.

While minding her own business, Cheetara is caught in a trap set by Safari Joe, the famously annoying hunter. After escaping, she rallies the other ThunderCats to help her stop Joe once and for all, by turning the tables and capturing him.

The ThunderCats have gotten so good at defeating the Mutants of Plun-Darr that it's basically become routine. That all changes with the arrival of the Mutants' old leader: Ratar-O, wielder of the Sword of Plun-Darr. Uh-oh.

Lion-O is happily playing with Snarf in their "Frolicking Field" and doesn't have a care in the world, unfortunately he's accidentally stomping all over the miniature village of the Micrits. The tiny people want to defeat the "giant orange monster" but such a quest would require a brave hero. Luckily, the Micrits have such a hero: Prince Starling. Now, let us the tell you the epic tale of Prince Starling as he journeys to find the fountain of growth and defeat the wicked Lion-O, who has no idea any of this is going on.

Lion-O and the other ThunderCats are thrilled to meet a brand new Thunderian: Lion-S. She's cool, good at fighting robots and, most importantly, thinks Lion-O and his Sword of Omens are really neat and interesting. Looks like the ThunderCats have a new best friend. Maybe even, a new ThunderCat?????