ThunderCats 1985 Season 3 Episode 20 The Last Day Episode Title:The Last Day.Episode Description:Impatient with Mumm-Ra failing them time and time again, the Ancient Spirits of Evil give him one final chance: destroy the ThunderCats within twenty-four hours, or face exile. To this end, he is granted extraordinary power, and grows to a gigantic size. Mumm-Ra spreads destruction all over Third Earth, sends Tygra, Cheetara, and Panthro to limbo, and buries Lion-O alive. He then attacks and destroys the Tower of Omens, and eventually sends the Thunderkittens to limbo too. Snarf goes into the Book of Omens to learn how to defeat Mumm-Ra. Jaga and the other ThunderCats in limbo help free Lion-O and he learns from Snarf that Mumm-Ra only has until sunset to defeat the ThunderCats. Mumm-Ra fails and the Ancient Spirits of Evil banish him from Third Earth.