Thundercats S02E06 Mumm-Ra Lives! Part I

Mumm-Ra is weak and faces the threat of three new ThunderCats; he sends the Mutants to release his old enemies, the Lunatacs, imprisoned in Dark Side in order to bolster the forces of evil. The ThunderCats' celebration of their victory over Mumm-Ra and the welcoming of three new ThunderCats is cut short when Snarf overhears plans at Castle Plun-darr after he chased Ma-Mutt there from the Berbil village