Third Earth’s depraved ruler will stop at nothing to prevent the end of his reign, including battling the ThunderCats.
The ThunderCats eventually crash land on Third Earth, a puzzling and alien plant.
Having been declared Lord of the ThunderCats, Lion-O leads the team as they adjust to their new surroundings and work towards making Third Earth their permanent home.
There would not be a story without a villain though, and that’s where the diabolical Mumm-Ra comes in.