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.