|This article is about a/an villain in Power Rangers S.P.D.|
- "I shall crush puny, so-called warriors in the name of the Magnificence. We shall not rest! We shall not show mercy! We shall be VICTORIOUS!!"
- ―Emperor Gruumm[src]
Emperor Gruumm, played by Rene Naufahu, is a figurehead who serves as the de jure leader of the Troobians, an alien empire whose ultimate goal is to conquer other worlds. Gruumm is relentless and nothing will stand in his way to conquer the universe. He previously destroyed the planet Sirius (home world of Anubis Cruger), and in 2025 he launched an assault on Earth. He was defeated by Anubis Cruger and captured in front of SPD Headquarters after Omni was destroyed by the S.W.A.T. Megazord.
All that's known of his backstory is that he works for Omni, a malevolent disembodied brain that Gruumm fears and worships as "the Magnificence"/"Your Magnificence".
Gruumm's main strategy is to overwhelm and devastate a planet with constant, large-scale assaults and then drain the planet of its resources, as shown in the flashbacks to the Sirian invasion, and used such tactics on the Helix Nebula simply to draw the A-Squad into an ambush. It's briefly shown that his ship can even destroy a planet from orbit.
Gruumm had conquered and slaughtered a large number of planets, with the Rangers once exaggerating to say he'd conquered everywhere but Earth. Kat Manx said that her own homeworld had fallen to the Empire.In the DVD "Meet The Ranger" features,
His highly destructive tactics show life means little to him. It was initially unclear why he wasn't using such tactics to conquer Earth, except on rare occasions where he simply lost his temper and struck in force or attacked personally; in each case, he would have won if not for outside intervention (new weaponry for Cruger, the Omega Ranger, and Dino Thunder Rangers respectively).It became clear later on that Gruumm had been working off a long term plan, intending not to leech and destroy Earth but instead to use its resources - which he looted over the course of the season - diamonds, gold, Iridium, and Hemotech Synthetic Plasma (which is used as a synthesizing agent) - to construct a body for Omni.
Emperor Gruumm has two aides, Mora/Morgana and Broodwing. He has a bitter hatred for Cruger, who cut off his right horn in the battle for Sirius. He is also the most powerful warrior among the Troobian empire, as proved in his victories over the B-Squad Rangers and Supreme Commander Fowler "Birdie". His main weapon is a staff that shoots, and he also rides a motorcycle with lighting laser cannons. Gruumm has the ability to use telepathy and shapeshift into a selected human form. In battle, he has shown the ability to decimate the Rangers, defeat Commander Birdie and also harm Zeltrax, though Cruger has shown the ability to defeat him.
During "Endings", Gruumm captures Cruger with help from the renegade A-Squad and then later B-Squad with Piggy's help. As Omni's body begins to take shape, B-Squad and Cruger escape and Cruger confronts Gruumm after capturing Mora. Gruumm threatens the life of Cruger's long-lost wife Isinia to try to force Cruger to surrender, but is instead thrown into the lava at the heart of Omni and apparently killed. After Omni is destroyed by the S.W.A.T. Megazord, Gruumm emerges from the wreckage in front of SPD Headquarters amidst the celebrations to face Cruger one last time. Unmorphed, Cruger battles Gruumm who proves no match for Cruger. After Cruger smashes Gruumm's staff, Gruumm orders Cruger to show him no mercy. Instead of killing Gruumm, Cruger cuts off the top of his remaining horn and contains Gruumm. As Gruumm yells threats from his card, Cruger shows it to the assembled forces of SPD and declares that "justice is served!" as everyone celebrates.
He appears in the Nintendo DS version of Power Rangers: Super Legends as the main villain who has set his sights upon the myth of the Hall of Legends, the resting place of the collected energies of Power Rangers across time. In his twisted mind he envisioned a world where his enemy's power is not only stolen, but used to make him a living god over all creation. In the console version of the same game, he is merely mentioned.
- Emperor Gruumm is the fourth final main Power Ranger villain who does not die, instead he is contained and trapped in an SPD card by Cruger. The first is Divatox, the second is Astronema, the third is Ransik and the fifth(possibly) is Venjix.
- Rene Naufahu would later play Mentor Ji of Power Rangers: Samurai.
- In Omega Ranger's original timeline, Gruumm did conquer Earth in 2025 and the planet was still calling for help in 2040.
- Omni was off-screen and communicating with Gruumm remotely. This meant that early in the show, it appeared that Gruumm was mad and talking to himself. Later, it became clear that another entity was in charge.
- Gruumm's history with Omni was not completely clear in the show.
- In an interview (9:26 in), co-producer Greg Aronowitz clarified that "Gruumm has always been Omni's puppet... [Gruumm] has power, but he has issues and he has weakness, and Omni has taken advantage of that for as long as time can remember." RangerCast interviews with Greg Aronowitz
- In a May 2014 interview Greg Aronowitz has stated that Gruumm's original concept was intended to be a homage to Sleeping Beauty's Maleficent as a power hungry and deranged villain. The skull and partially exposed brain was due to Aronowitz's fondness for such things, as well as to show that Gruumm was hiding his true nature and was also both intelligent and had a weak point.
- Gruumm has no Super Sentai counterpart, the main villain of Tokusou Sentai Dekaranger is Rainian Agent Abrella, though he is the counterpart of Broodwing
- Rainian Agent Abrella - Super Sentai counterpart in Tokusou Sentai Dekaranger. See comparison page. (in terms of main antagonist)