In Thundercats Origins: Heroes and Villains, a story is told about a loyal Egyptian Vizier named Wahankh.
In truth, his loyalty was a mere guise as he was plotting to overthrow the royal line, seeking for assistance from the Ancient Spirits of Evil. The Spirits consented to his wish and empowered him with their dark magic, turning him into an immortal sorcerer but trapped in his mutated, cadaverous grey body. The Spirits gave Wahankh a new name: Mumm-Ra.
Confident wielding his newfound powers, Mumm-Ra confronted the pharaoh and ordered him to kneel before his grotesque figure. The pharaoh's son, however, having discovered Mumm-Ra's plot earlier, attacked Mumm-Ra nonetheless and outmaneuvered him.
Following his defeat, the pharaoh decided to spare him his death sentence and locked him as a mummy in a pyramid instead. Still unable to die, Mumm-Ra begged the Spirits for help but was denied more power for his incompetence. Instead, the Spirits commanded Mumm-Ra to build giant statues of them within his burial chamber, a task which required six centuries to complete.
Finally, the Spirits broke him free and turned him into "Mumm-Ra, the Ever-Living".
Mumm-Ra is a native to the planet Third-Earth where the Thundercats land after their home planet explodes. Mumm-Ra is defined as the very essence of evil. He is the main antagonist of the show and his original goal was to steal the Eye of Thundera to harness its powers, but this quickly changes to out right destroying the Thundercats. Mumm-Ra prefers to use others for his bidding either through deception, trickery or fear. Most of the time he uses the Mutants of Plun-Darr for his schemes though they usually fail. In the instances Mumm-Ra does decide to take matters into his own hands he calls upon the power of the Ancient Spirits of Evil which transforms him into Mumm-Ra the Everliving which is his hulked form. In order to do this Mumm-Ra must recite "Ancient spirits of evil, transform this decayed form to Mumm-Ra, the Ever-Living!". Mumm-Ra in this form is much more powerful physically and mystically . It grants him super-strength, super durability flight, shape-shifting into different forms, firing energy bolts and casting spells. Mumm-Ra also knows other mystical capabilities such as telepathy, telekinesis, levitation, alchemy, temporal manipulation, and astral projection. Mumm-Ra has a super form in which he becomes much larger and more powerful than his ever living form. Mumm-Ra also wields the powerful Sword of Plun-Darr, which is very nearly a match for the sword of Omens and caused the disruption that destroyed Thundera.
Although, Mumm-Ra is not without his weaknesses. Mumm-Ra acts a conduit for the spirits of evil and once he reaches a certain limit of power expenditure, he must return to his sarcophagus to restore his power. Mumm-Ra's powers are connected to his sarcophagus and his statues, so if any are damaged or destroyed Mumm-Ra becomes severely weakened. One weakness Mumm-Ra used to have was that he could not stand to see his own reflection,although the ancient spirits cured him of this affliction in the end. It is stated that "Wherever evil exists, Mumm-Ra lives!"
Mumm-Ra is back in the Thundercats cartoon series remake as the main antagonist. Like in the original series, Mumm-Ra is empowered by the Ancient Spirits of Evil, and appears in a mummified corpse-like form until he recites a spell which turns him into his hulked and winged "Everliving" form.
Many centuries prior to the series, Mumm-Ra is an interstellar conqueror travelling aboard a spaceship, who commands an army of animal slaves, with the Thundercats as his enforcers. He has collected three out of four power stones representing the Ancient Spirits of Evil and uses them to empower his Sword of Plun-Darr. During his conquest of the planet Third Earth, his most trusted lieutenant Leo, ancestor to the Thundercat monarchs, plants the newfound Eye of Thundera, then called the War Stone, into a sword to create the Sword of Omens and defeats Mumm-Ra in sword combat. Stripped of his sword and trapped in his weak form, Mumm-Ra escapes death by sealing himself in a pod to regenerate his powers, meanwhile his ship crashlands on Third Earth. His plan backfires when the Thundercat Panthera, another of his lieutenants, smashes the control panel to his pod, trapping him inside for the many years to come.
After centuries of being trapped inside his pod, Mumm-Ra telepathically contacts nearby Thundercat warrior Grune, then sent by King Claudus on a mission to find the Book of Omens alongside Panthro. Mumm-Ra offers power to the paranoid and disillusioned Grune should he free and serve him. Grune accepts, much to Panthro's anger and disappointment. Mumm-Ra is once again free and unchallenged in his search for the power stones.
At the beginning of the series, Mumm-Ra amasses and arms an army of Lizardmen with technology to conquer Thundera and retrieve the Sword of Omens from the Thundercats' king, Claudus, in order to extract the Eye of Thundera. He appoints Grune and the Lizardman Slythe as his generals. He succeeds in destroying the Thundercats' army, killing Claudus, and enslaving most of the Thundercats. The Sword of Omens, however, eludes his grasp as Lion-O, Claudus' heir, has escaped with it.
The majority of the first season involves Mumm-Ra and the Lizard Army pursuing Lion-O's company. After Slythe fails to capture the Thundercats and Panthro joins the company, Mumm-Ra goes after them personally and by enslaving the cleric Jaga's spirit, arrives at the Tower of Omens just in time to confront the company. It was here where, for the first time in the series, Mumm-Ra recites his spell and transforms into his hulking Ever-living form.
He easily defeated Panthro and Tygra, then outraces them to the top of the Tower where the Book of Omens is kept. Before he can gain control of it, however, Lion-O attacks him with magic from the Sword of Omens, forcing him to abandon his Ever-living form and flee the scene in the form of a raven.
Mumm-Ra is not seen again until the season nears its finale. When Lion-O's company has located the second power stone, the Spirit Stone, in an Elephant village, Mumm-Ra orders Grune and Slythe to commandeer an assault on the village. The company join with the Elephants to stall the attack while Lion-O and Tygra enter the Astral Plane in search of the Spirit Stone, closely followed by a raven.
Mumm-Ra manipulates the Astral Plane's environment to remind Tygra and Lion-O of a fearful childhood experience in an attempt to make them kill each other, but fails. Mumm-Ra uses his Ever-living form once more to fight the Thundercat brothers, but Lion-O gains control of the Spirit Stone first. As the Astral Plane collapses in a massive explosion, Mumm-Ra is forced to flee for the second time.
At the beginning of Season 2, Mumm-Ra berates Slythe for his incompetence as the Lizard Army are crumbling apart and tasks him with recruiting criminals Addicus and Kaynar to serve as generals in replacement of Grune, who was trapped in the Astral Plane following its explosion.
When the Thundercats close on a third power stone, Mumm-Ra and his Lizard Army laid pursuit meanwhile Pumyra, an embittered undead Thundercat Mumm-Ra had raised during the invasion of Thundera now acting as a mole, feigns affection to Lion-O and goodwill to the Thundercat company.
Powers and Abilities
Immortality: Mumm-Ra is ageless and is unable to die from natural causes.
Intellect: Mumm-Ra, with the help of his army, has built technology vastly more advanced than even contemporary real world technology. These include laser-based assault rifles, heavy grenade launchers, battle mechs, hovercraft, and spaceships.
Shapeshifting: Mumm-Ra can transform himself into various different forms. His most common transformations are his "Ever-Living" form which is used for heavy combat, and his raven form which he uses to travel quickly. He also has a Thundercat form dubbed Pumm-Ra.
Necromancy: Mumm-Ra has the ability to raise creatures from the dead, shown when he resurrected the Thundercat Pumyra.
Healing: After sustaining major attacks in his Ever-Living form, Mumm-Ra reverts to his mummified form to heal all his wounds and regenerate his energy.
Telepathy: Mumm-Ra can contact others mentally, although telepathic contact is limited by distance.
Flight: His Ever-Living and raven forms possess wings, granting flight.
Fire and Ice Control: Mumm-Ra's array of spells include both flames and freezing attacks.
Hypnosis and Possession: Mumm-Ra has been shown to force other beings to do his bidding, either through hypnosis or taking over their bodies.
Swordsmanship: Mumm-Ra has been shown to be proficient using his Sword of Plun-Darr.
Unarmed Combat: While unarmed in his Ever-Living form, Mumm-Ra has overpowered the likes of Panthro, armed with nunchucks, in an all-out combat and countered a sneak attack from Tygra.