The character Unicron first appeared in the opening scene of 1986's The
Transformers: The Movie, immediately making clear his driving goal by consuming
the small world of Lithone in the year 2005. Subsequently, when the battered
bodies of Decepticon leader Megatron and several of his troops were set adrift
in space by Starscream following a furious battle with the Autobots, Unicron
appeared before them and offered Megatron a deal: in exchange for a new body,
and new troops, Megatron would destroy the Autobot Matrix of Leadership, the
only thing that could stand in Unicron's way. Thus, Megatron became Galvatron,
and began to carry out his assigned task, although he was loath to do so. When
Galvatron showed any signs of opposition to Unicron's will, Unicron inflicted
agonizing torture on his servant, even from a great distance, to coerce into
obedience. Following Unicron's consumption of Cybertron's two moons, Galvatron
successfully obtained the Matrix, believing he could use it to bring Unicron under
his control. Attempting to open the Matrix to intimidate Unicron, Galvatron only
prompted his transformation into robot mode, and was swallowed by the planet-eater.
Unicron proceeded to lay waste to Cybertron, halted briefly when the young Autobot,
Hot Rod crashed a Quintesson spacecraft through his eye. Finding Hot Rod inside
Unicron's body, Galvatron suggested an alliance against their common enemy. However,
Unicron inflicted his mental torture upon Galvatron, forcing him to fight Hot Rod.
Hot Rod took the Matrix from Galvatron during the battle, and became Rodimus Prime.
Rodimus threw Galvatron into space, and opened the Matrix within Unicron, destroying
his body, leaving only his head drifting in space.