The series follows the journey of a group of cat-like humanoids from the planet Thundera, who are on a mission to protect their home planet and the universe from evil forces. Led by Lion-O, a young and powerful leader, the ThunderCats team consists of Tygra, Panthro, Cheetara, Snarf, and Jaga (in later seasons). Their arch-nemesis, Mumm-Ra, a powerful and evil sorcerer, seeks to conquer Thundera and rule over the universe.