The Ancient Spirits of Evil are four malevolent spectral entities from the Thundercats universe. These beings are pure manifestations of evil and they constantly scheme against the inhabitants of the mortal plane, manipulating others to carry out their wishes. The Ancient Spirits' primary instrument for for carrying out their will is the undead sorcerer Mumm-Ra, whom they imbue with incredible magical power so that he may perform acts of terror and destruction in their name. The Spirits have come to recognize the Thundercats as the greatest threat to their plans, their code going against everything that the Spirits stand for. They have charged Mumm-Ra with destroying the Thundercats and the Eye of Thundera, but Mumm-Ra has failed them time and again.