Synopsis

Weakened, Mumm-Ra now confronts the challenge of three newly arrived ThunderCats; to strengthen his dark legions, he dispatches his Mutants to unleash the Lunatacs – ancient foes imprisoned within Dark Side. The ThunderCats' joyous celebration of their triumph over Mumm-Ra and the welcoming of these new allies is abruptly halted when Snarf, pursuing Ma-Mutt from Berbil village, overhears a sinister plot at Castle Plun-darr.