Following Unicron's consumption of Cybertron's two moons, Galvatron obtains the Matrix from Ultra Magnus, believing he can use it to bring Unicron under his control. Attempting to open the Matrix to intimidate Unicron, Galvatron only prompts his transformation into robot mode and is swallowed by the planet-eater. Unicron lays waste to Cybertron, halted briefly when the young Autobot rookie, Hot Rod, crashes a Quintesson spacecraft through his eye. Finding Hot Rod inside Unicron's body, Galvatron suggests an alliance against their common enemy. However, Unicron inflicts his mental torture upon Galvatron, forcing him to fight Hot Rod. Hot Rod seizes the Matrix from Galvatron during the fight and becomes Rodimus Prime. Rodimus throws Galvatron into space, freeing him from Unicron's mind-control. Rodimus opens the Matrix within Unicron, destroying his body, leaving only his head, which becomes a moon of Cybertron. As Unicron's head drifts around in space the movie ends, with the credits shown in a background of his head floating in space.