Rocketron (voiced by Glen McDougal) is a robotic rocket monster under the command of Barbarax. Aided by the Swabbies, he was sent to stop the Galaxy Rangers from leaving Captain Mutiny's planet and reporting the true nature of the Machine that would help the Terra Venture escape The Lost Galaxy. After the Rangers defeated his Swabbies, Rocketron engaged the Rangers himself. Finally, Leo summoned the Red Capsular Cycle and attacked Rocketron with Fireball Mode, shattering his body. Rocketron reformed and grew giant, causing the Rangers to summon the Galaxy Megazord. Rocketron was unable to defeat the Galaxy Megazord and activated his self-destruct, holding the Megazord to himself so that his self-destruct would destroy it as well. In response, Leo summons the Stratoforce Megazord which attacked Rocketron, forcing the monster to release the Galaxy Megazord. The Stratoforce Megazord restrained Rocketron and the Galaxy Megazord struck him down with a charged strike from the Galaxy Megazord Saber, apparently destroying Rocketron.
After the Rangers left, it was revealed that Rocketron survived once again and had reformed in his usual size. However, Deviot grabbed Rocketron and drained his energy to restore himself to his normal form. Deviot walked away as Rocketron begged for his energy back before exploding from the loss of his life energy.