Plot Summary: Following the destruction of their home planet Thundera, the surviving Thunderans (a cat-human race) hope to find a new home, only to be attacked by mutant pirates. All but one Thunderan ship are destroyed by the mutant attacks. Aboard that ship, Jaga instructs seven other Thunderans to board their stasis pods while he directs the ship to the nearest planet Third Earth. The ship crashes, Jaga dies and the other Thunderans call Third Earth their new home. Gifted with the ability to use the coveted Sword of Omens, the young Lion-O takes leadership of the Thundercats to battle the mutants and their new leader Mumm-ra, who has awakened from his eternal sleep on the planet.