Lion-O faces Mumm-Ra in a final showdown on Third Earth...and triumphs! As punishment for failing their task to eliminate the TunderCats, the Ancient Spirits of Evil exile Mumm-Ra to the edge of the universe. With Mumm-Ra gone, the ThunderCats can safely rebuild their home planet New Thundera. But new dangers threaten the fledgling civilization, forcing these brave pioneers to push their powers to their limits. And then the unthinkable occurs: Mumm-Ra returns more determined than ever to destroy them! Pounce on more than 11 hours of action-packed animated adventure.