ThunderCats is an American/Japanese animated television series, produced by Ethan Spaulding and Michael Jelenic. A reboot of the original 1980s TV series of the same name (which ran from 1985 to 1988), ThunderCats was developed by Warner Bros. Animation and Studio 4°C, and combined elements of western animation, with Japanese anime. The series began with an hour-long premiere on Cartoon Network on July 29, 2011.
Following the destruction of their home, the kingdom of Thundera, the ThunderCats (a group of humanoid cats) are forced to roam the planet Third Earth, in order to find a way to defeat the evil sorcerer Mumm-Ra, who plans on taking over the universe. Story-wise the series attempts to take a much darker and more cinematic approach than the original show, featuring a lot more focus on characterization and more sophisticated themes.
Initially planned for 52 episodes, it was confirmed by ThunderCats art-director Dan Norton in early 2013 that the show had been canceled after only one season. Reruns of the show later aired on Adult Swim's Toonami block along with Sym-Bionic Titan.
On the planet known as Third Earth, the Cats have lived and thrived for generations in the kingdom of Thundera. The Cats are led by Claudus, with his son and heir Lion-O. However, one night the kingdom is attacked by the Lizard army led by the evil sorcerer Mumm-Ra. With them, the Lizards bring technology (a concept unfamiliar to the Cats). Because of this, Thundera is destroyed, Claudus is killed by Mumm-Ra, and the rest of the Cats are enslaved. A small band of surviving Thunderians led by Lion-O (who wields the powerful Sword of Omens) flee the destroyed city in order to seek out the Book of Omens which is said to have the knowledge needed to defeat Mumm-Ra. Once they find it, the ThunderCats realize that in order for them to defeat Mumm-Ra, they must unite all the different species living on Third Earth. The ThunderCats also discover that they have to find three stones of power which if found by Mumm-Ra will give him power to become the most powerful being in the universe.