Unicron is a character from the Transformers universe and toyline. Created by Floro Dery, he was introduced in the 1986 animated film The Transformers: The Movie as the film's main antagonist. Neither Autobot nor Decepticon, Unicron is a prodigiously large robot whose scale reaches planetary proportions, and he is also able to transform into a mechanical planet.
Transformers: Generation 1
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 him 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, freeing the Decepticon from Unicron's mind-control, and opened the Matrix within Unicron, destroying his body, leaving only his head, which became a moon of Cybertron.
Controversy surrounded the revelation of Unicron's cartoon origin, with many fans taking a dim view of his origin as the creation of a primate. The wildly different origin for Unicron presented in Marvel Comics proved to be overwhelmingly more popular, and has shaped Unicron in fiction twenty years hence.
Far more than a mere product of science, as in the cartoon, Unicron was a fallen god from before the universe existed, who sought the ultimate peace that would be granted by the destruction of all life. Amazingly, Unicron accomplished this task, wiping out all life, planets, stars and nebulae, even "the stuff of space itself" in the universe and leaving only nothingness and void. His lust for destruction finally sated, Unicron entered a deep sleep - but he had not been thorough enough. Tiny fragments of the old universe reacted with each other, and a new universe was born. As Unicron slept, the core of this new universe - somehow a sentient being - became aware of Unicron's threat and created a defender to battle his evil - Primus, the lord of light. Unicron awoke to find himself surrounded by another universe, and simply began to destroy it again.
He and Primus clashed many times, the force of their battles wiping out the very life Primus had been created to protect. To stop this physical destruction, Primus shifted the battle to the astral plane, where he fared little better, forcing himself into what seemed to be a sacrifice play - in shifting the battle back to the physical universe without time to properly generate their energy forms, Primus entrapped both himself and Unicron in two barren asteroids. But this was not the end of Unicron - over the eons, he learned to psionically shape his asteroid, and transformed it into a metallic planet, and then again into a gargantuan robot. Primus, fearing that to follow suit by forming himself in a similar manner would simply pick up the conflict where it had left off, sought an alternative way to defend the universe against the threat of Unicron by turning his asteroid into the planet Cybertron; a planet that he populated with robotic beings that, like Unicron, could alter their forms. And thus were born the Transformers.
The origin in American Marvel Comics was not revealed immediately, however. Unicron's slightly convoluted comic tenure began in the United Kingdom's exclusive Transformers comic series, which interspliced its own original stories with reprinted American material. Jumping at the chance to work with a new cast of characters not involved in the American comics, writer Simon Furman decided to cannibalise the best elements of the movie and work them into his stories, creating a future universe based on the movie's events, but different from the cartoon. In the first use of this timeline, in the mega-serial, Target: 2006, Galvatron travelled back in time in an attempt to escape the control of Unicron, but Unicron was able to ensnare the minds of three Autobots - Hot Rod, Kup and Blurr - and send them back in time after him to foil his plot. Though Unicron's role in the story itself was suitably minor, it offered the first glimpse of his greater mental power.
In the comics' version of post-movie events, Unicron's head did not enter Cybertron's orbit, and instead crash-landed on the Planet of Junk. Still active, Unicron used his vast mental powers to enslave the minds of the Junkion natives, who set about rebuilding his body. Cyclonus, Scourge and the bounty hunter, Death's Head, also fell prey to him, and he used them to exacerbate the stalemated war on Cybertron to keep the Autobots busy, so that they would not learn of his impending resurrection. When Death's Head fought back against Unicron's mental control, however, Unicron rewarded his temerity by revealing the comic book version of his origin. Death's Head then aided Rodimus Prime, projecting his mind into Unicron's where they battle, until Unicron's head was destroyed by explosives, and his essence was sealed within the Matrix. Rodimus and several other future Autobots subsequently travelled back in time to 1989 and participated in the "Time Wars", but when they attempted to return to their own time afterward, they discovered that disruptions to the timestream had erased their future, and replaced it with one where the Decepticons ruled Cybertron. In this dark future, Unicron's essence emerged from the Matrix and briefly took over Rodimus Prime, before he was thwarted by the removal of the Matrix from Rodimus's body. In 2010, however, Unicron attempted this again and succeeded, controlling Rodimus's body and reshaping it into his own image, before being defeated by Rodimus's own force of will.
In 1987, Simon Furman began writing the U.S. Transformers series in addition to the UK comics, and immediately set in motion an epic Unicron-themed story. The alterations made to the timeline by time-travel and disruptions to the fabric of reality in the UK comic set the comic book universe on a path that would not lead into the movie/post-movie timeline originally depicted as its future, and Unicron soon made his presence known to the Transformers much earlier than 2005.
A battle between the Autobot Classic Pretenders and the Decepticons' Mayhem Attack Squad at the centre of Cybertron had the unfortunate side effect of waking the slumbering Primus, who was struck by a stray laser blast and awoke with a scream. Although he immediately sank back into slumber, Primus's scream echoed throughout the universe, to the fringes of known space where Unicron heard it. Now aware of his old enemy's location, Unicron immediately headed towards Cybertron, but, seeking a herald to sow chaos in his name ahead of his coming, used his formidable powers to send three agents - Hook, Line and Sinker, forward in time to an alternate future version of 2009. In this timeline, Unicron had succeeded in consuming Cybertron in the year 2005, and Galvatron and the Decepticons ruled Earth. This timeline's version of Galvatron was pulled back to 1990 by Hook, Line and Sinker and press-ganged into Unicron's service, but, like his predecessors, turned on his master by forcing Emirate Xaaron to awaken Primus in hopes of destroying Unicron. Primus possessed Xaaron's form and attempted to hold off Unicron, but he was weak, and his attack was a ruse, leading to his own destruction, which in turn (along with a direct attack by Galvatron) succeeded in galvanising the Autobots and Decepticons to attack Unicron together. Ultimately, they did little damage, and many Transformers died (including Waverider) before Optimus Prime was able to use the Matrix to destroy Unicron, exploding his body from within.
In The Transformers: The Movie, Unicron (whose lips never moved when he spoke) was voiced by Orson Welles. Unicron proved to be Welles' final role, as he died a few days after completing work on the project; rumors persist that Welles did not complete recording of all his lines, and that Leonard Nimoy filled in for him, but director Wally Burr and actress Susan Blu refute the claim. There were two early attempts to produce Unicron toys for the Transformers toyline, featuring voice clips from Welles himself, but the results never made it to production. It was not until 2003 that a production Unicron toy was finally issued. For the 20th anniversary of the original movie, Diamond Select released an eight and a half inch tall statue of Unicron and Rodimus Prime.
The third season of the Transformers animated series continued Unicron's story from where the movie left off, as the planet-eater's deactivated head settled into orbit around Cybertron, a grisly monument to the moons he had destroyed. His head was soon visited by Cyclonus, who accessed the memory bank to discern the fate of Galvatron, who had been hurled from Unicron through space by Rodimus Prime. Some time later (Episode 81: "Ghost in the Machine"), the ghost of deceased Decepticon Starscream reactivated Unicron's head and entered into a bargain with him, performing three labors in exchange for the restoration of his body. Starscream (inhabiting and controlling Scourge's body) gathered for Unicron Metroplex's eyes (breaking one and replacing it with one from Trypticon) and Trypticon's transformation cog, and then began connecting his head to Cybertron, which would become Unicron's new body. Starscream demanded that Unicron restore his own body so that he could complete the required connections; but once Unicron had done so, Starscream, somewhat predictably, double-crossed him and refused to finish the job. Unicron's head was subsequently blown off into space by an explosion instigated by the Autobots.
Later, when searching for a new supply of positrons (anti-electrons), the Decepticons ventured to Unicron's head, where Cyclonus and Scourge accidentally awoke the slumbering demi-god. At the same time, Grimlock - who had gained super-intelligence through an infusion of anti-electrons - had constructed from pieces of Unicron's head the Technobots, and one of their number, Strafe, severed enough of Unicron's neural connections to shut him back down.
Although Unicron himself did not appear again, his origin in the animated series was later revealed. Unicron was created near the beginning of the universe by the diminutive genius known as Primacron, who intended for him to devour all life in the universe, leaving a blank slate that Primacron could use as he saw fit. However, Unicron turned upon Primacron, deciding that he would rule the universe and subsequently setting out to achieve that goal.
Unicron's head was seen one last time as Primacron's new creation had crippled Cybertron. This time the head looked very old and almost stone-like, underlining that Unicron was finally dead.
When the Generation 2 animated series was aired, animated bits of the film with Unicron in it were edited into the episode "More Than Meets The Eye Part 1." 
In contrast to his major roles in the Marvel comics, the cancellation of the Dreamwave Transformers comics meant that Unicron would play a much lesser role in events. His presence was first hinted at in the second "War Within" arc, where the Fallen enlisted the Chaos Trinity (Bludgeon, Bugly and Mindwipe) to capture a number of Transformers (Grimlock, Blitzwing, Jetfire and Hot Spot) for an arcane ritual to summon the Fallen's Master. It failed, due to a combined strike by Prowl's Autobots and Shockwave's Decepticons, with the Fallen being killed by Primus himself.
He would make his first mainstream appearance in volume 3, issue 1 of the main Generation One series, seemingly summoned by Shockwave at the end of the previous volume. Here it is revealed that he had dispatched Scourge at the head of a huge armada of Sweeps to search the galaxy for Cybertron. Scourge located it, but was shot in the back and deactivated by Shockwave, who used analysis of his body to create the Triple Changers. Unicron then destroyed Lithone, before beginning to journey to Earth. Dreamwave went bankrupt and the next issue was never released. Writer Chris Sarracini has indicated that he would have followed through on the Unicron storyline, and also would have had the Dreamwave version of Cyclonus rescue Scourge from US government study.
Devil's Due Publishing
Unicron made a cameo appearance in the second G.I Joe vs the Transformers crossover produced by Devil's Due. At the end of the arc Cobra operative Doctor Mindbender would meet with the cult Cobra-La and discover they had allied themselves with Unicron. One of Optimus Prime's visions of the future showed Mindbender and Unicron as a coming threat - a prophecy that came to pass in the fourth crossover "Black Horizon".
Apparently banished from his world thousands of years ago, Unicron travelled the galaxy, devouring planets to quench his hunger and taking their populations as slaves to maintain his inner body works. However, when attacking the seemingly primitive and defenseless Earth, Unicron ran into trouble. A strange set of non-human creatures opposed Unicron, threatening to attack him with a metal devouring organic spore. Before the two sides could annihilate each other, an agreement was reached favouring both parties. The creatures would go into hiding, allowing humanity to develop. Then, when they had reached a sufficient technological level to serve as slaves for Unicron's inner workings, the creatures would call Unicron. He would destroy humanity and they would inherit the human-free world he left behind. Thousands of years later the pact would be kept and the creatures, now calling themselves Cobra-La, would summon Unicron via a beacon. Attacking a pirate vessel on the outskirts of a solar system, Unicron then journeyed to Earth. Hailed as the "Doom Star" by terrified humans, Unicron transformed to robot mode and prepared to destroy humanity. However, he was thwarted when Cosmos and Flint traveled through his mouth into his body bearing the metal-eating spores of Cobra-La. Despite the best efforts of his "anti-bodies" (the Beastformers), they delivered the spores directly to his brain. Although he was not shown to be destroyed, he was last seen entering convulsions, indicating he would no longer be a threat. It was later mentioned his body was floating around Earth.
In this continuity, Unicron is thought of as the Transformers' equivalent of the "boogeyman". The revelation that Unicron had been banished from his home planet indicates a different origin from ones used for previous incarnations of Unicron.
Although the real Unicron did not make any appearances in 1996's CGI animated series, Beast Wars, his legend held strong. Starscream's ghost spun a lie that claimed Unicron had destroyed him (Unicron's planet mode was seen in Starscream's fabricated flashback), and when the mysterious alien race known as the Vok directly communicated with Maximal leader Optimus Primal, they searched his mind for an image that he would fear and respect, found Unicron and took his form. Later, in Season 3 of Beast Wars, it was revealed that Tarantulas had attempted to destroy both Autobots and Decepticons in the Ark, as he and the Tripredacus Council were descended from a different lineage than Autobot or Decepticon, and would hence inherit Cybertron all to themselves. Although never directly stated, it is implied that the ancestor of Tarantulas and the Council is in fact Unicron; Megatron refers to Tarantulas as "Unicron's spawn" in the Beast Wars episode "Nemesis Part 1". In Episode 16 of Beast Machines, Rattrap compares Megatron's floating head fortress to Unicron's head floating around Cybertron.
Beast Wars II and Beast Wars Neo
Conversely, Unicron played a large role in the two Japanese-exclusive cel-animated Beast Wars series, Beast Wars II and Beast Wars Neo. Following the events of Transformers: The Movie and Unicron's demise, the Angolmois energy that gave Unicron life was left sealed within planet Gaia (a future version of Earth). When the war on this planet between the forces of Maximal leader LioConvoy and Predacon leader Galvatron (a different individual bearing the same name as Unicron's original creation) culminated in the explosion of Galvatron's Nemesis battle fortress, the resultant energy surge revived Unicron's consciousness. Seeking to complete his resurrection, he created the Blentrons to gather the Angolmois Capsules his life-energy was now sealed in, and then proceeded to possess the lifeless body of Galvatron as a temporary host. After gathering the capsules, Unicron attempted to make Cybertron his new body, but was finally defeated by Maximal commander Big Convoy and his Matrix Cannon.
As with his original incarnation, there was a failed attempt to make Unicron into a toy for the Beast Wars Neo line, and although regarded as quite impressive, the prototype - which, notably, does not resemble Unicron from the Beast Wars Neo series at all - did not make it into the production.
While writer Simon Furman had ruled out Unicron in the main IDW G1 series, this did not prevent him from using Unicron in his Beast Wars series. The series opened with a disembodied Magmatron, trapped in temporal limbo by Razorbeast at the end of The Gathering, watching the annihilation of the future Cybertron by Shokaract and Unicron. Unicron himself appeared in spectral form in issue #2, dispatching Rartorata to Earth to stop an anomaly in the timestream (the disembodied Magmatron) from interfering in the "ascending". Unicron planned to use Shokaract as a vessel through which to reemerge into the universe and destroy Cybertron. However, his plans were defeated when an unlikely alliance of Maximals and Predacons succeeded in battling his Heralds. While this was going on Ravage transported Shokaract into Magmatron's limbo realm. Realising the truth of Unicron's intentions, Shokaract then killed himself.
In the Binaltech saga, the future Ravage seen in Beast Wars alters the original G1 timeline. His interference includes trapping all the Decepticons in a spacial rift, with the knowledge that Unicron would soon be attacking Cybertron. The plan was that the Autobots would have to face Unicron unaided, and the Decepticons would then be able to return and conquer whoever prevailed. As a result of these changes, the final showdown between Optimus Prime and Megatron does not occur, and Prime does not die. With Megatron trapped in the rift, Unicron does not encounter the Decepticon leader, and therefore does not make the Faustian Pact to reformat him into Galvatron.
Through the events of the story, Optimus Prime learns that the Matrix can destroy Unicron, and he and Ultra Magnus launch an assault on the giant. Within Unicron's body, Optimus Prime is severely damaged, and although not mortally, he passes the Matrix to Magnus, who completes the mission, and the pair escape as Unicron explodes.
Although Unicron had played a major role in the above-mentioned Japanese series, he had not been featured as a major player in American fiction for over a decade. That all changed with the advent of the three co-produced series Transformers: Armada, Transformers: Energon and Transformers: Cybertron, which reintroduced Unicron to American audiences and finally rendered him in toy form, with the Mini-Con partner Dead End. In reference to Unicron's key role in these three series, Hasbro's head of Transformers, Aaron Archer, has collectively dubbed them "The Unicron Trilogy".
This incarnation of Unicron was never shown to physically consume planets in the same manner as his G1 predecessor, only to blast and absorb the remains. However, during his battle with Optimus Supreme, who had grown to Unicron's size, Unicron demonstrates that he had enough power to simply destroy a planet completely without consuming it. However, several references were made to consumption, so he may indeed perform the action. For example, in one of the mini-comic books packed in with the later Armada toys, Unicron is indeed illustrated literally eating an asteroid or moon whole. This Unicron was voiced by Mark Acheson in the US, and by Katsumi Chō in Japan.
A primal force of evil from the beginning of time, his origins lost to the mists of history, the Armada universe's incarnation of Unicron was the embodiment of the darkness and hate that lurks in the hearts of all beings. Having been defeated by the Autobot warrior Omega Supreme at some time in the ancient past of Cybertron, Unicron hid himself in plain sight of the Transformers, disguised as the planet's moon. In order to re-energise himself, Unicron implanted some of his own cells within Cybertron, where they grew and "hatched", giving birth to the diminutive race of robots called the Mini-Cons. It was Unicron's intent that these small robots would increase the ferocity of the Autobot/Decepticon war, allowing Unicron to feed off the hatred that the war fermented - but as a result of interference by human children, displaced in time from the 21st century, the Mini-Cons developed sentience, and fled Cybertron, crashing on Earth, where they lay dormant for a million years.
The subsequent awakening of the Mini-Cons once again increased the pace of the war, and to hasten the proceeding, Unicron created another being from his own body, Sideways, to serve as his agent for the purpose of constantly manipulating the events on Earth to keep the balance of power forever shifting, the ferocity of both sides constantly increasing. At the culmination of his plan, the Decepticons came into possession of all three Mini-Con weapons - the Star Saber, the Skyboom Shield and the Requiem Blaster - which Sideways and Thrust then stole and used to reactivate Unicron.
Shedding his lunar skin, Unicron transformed to robot mode and turned on Cybertron as the combined Autobot/Decepticon armada attempted in vain to stop him. Optimus Prime and Megatron (now Galvatron) entered his body with the human children, and Unicron addressed them through Sideways's form, absorbing all but Optimus into his collective consciousness and bringing the Mini-Cons back under his control. However, from within Unicron's mind, Rad was able to use his connection to High Wire to restore the Mini-Cons' individual minds, freeing the weapons and deactivating Unicron. With the danger apparently over, Galvatron challenged Prime to a final battle, but the hatred between the foes stirred Unicron to life again, and Galvatron realised that to break the circle, he had to sacrifice himself. Plunging himself into Unicron's maw, Galvatron ended the hatred, and in a mighty flash, Unicron vanished without a trace.
However, Unicron's body was inactive, badly damaged from his previous battle, and ten years after Galvatron's sacrifice a former victim of Unicron chose to strike. Within Unicron's shell, the Spark of Alpha Q, ruler of Planet Q, which Unicron had consumed in the past, still existed, and from Unicron's body he created the Terrorcons to gather Energon, which he would use to regenerate all the worlds Unicron had devoured. However, Megatron's corpse and Spark remained within Unicron, and slowly siphoned off some of the gathered Energon, allowing him to be reborn in a new body through the unintentional actions of Scorponok. Hunted by Megatron, Alpha-Q then jettisoned Unicron's head and escaped in it, while Megatron took over Unicron's body and continued to gather Energon in order to rebuild Unicron to use as his ultimate weapon. As the climax of this plan neared, a joint attack by Alpha-Q, the Autobots and their human allies saw all of Earth's Energon channeled into Unicron's head, which Alpha-Q then rammed into Unicron's body. The positively-charged Energon of Earth reacted with the negatively-charged Energon running through Unicron, tearing open a fissure in reality leading to a new area of space where planets Unicron consumed were recreated and sustained through the Energon radiated from Unicron's head, which had now become a glowing red sun.
Unicron's body, damaged once more, lay in the dark reaches near the fissure, and the Decepticons began to raid Alpha-Q's new planets for the Energon necessary to revive Unicron again. This time, they succeeded, and Megatron directed Unicron's body to retrieve his head, extinguishing the Energon Sun and killing Alpha-Q in the process. But the power of Unicron proved too much for Megatron to control, as Unicron began to take over Megatron's body. In the ensuing battle Unicron's body was successfully destroyed by super-powered Optimus Supreme with help of some of the other powered Autobots. Unicron's body was destroyed - but unbeknownst to anyone, he lived on in two forms: his minuscule Spark, and his consciousness, which lay buried in Megatron's mind. With quiet, subconscious nudgings, Unicron led Megatron to a massive reservoir of "Super Energon" beneath Cybertron's surface, which transformed him into Galvatron upon his first exposure. After a series of failed battles, Galvatron proceeded to expose himself to the Super Energon once again, and this time grew to a gigantic height. Unicron seized control of his body again for a new vessel and set out to rejoin with his Spark, but a Primus-empowered Optimus Supreme engaged him in battle once more, and drew all of Unicron's consciousness out of Galvatron and sealed it within his own Spark. Enraged, Galvatron prepared to destroy Unicron's Spark, but it merged with him, enlarging him again, leading to another battle with Optimus Supreme, this time bolstered by the combined energy of all his troops' Sparks. Meanwhile, Primus merged with the Super Energon, creating a foundling sun which arrived at the site of the battle. Taking control of his body for a brief moment, Galvatron once again sacrificed himself in order to stop Unicron, plunging himself into the infant sun, which ignited and gave new life to Alpha-Q's worlds.
With Unicron's destruction in Energon, the collapse of his body resulted in the creation of an enormous black hole which, if left unchecked, would consume and destroy everything. This necessitated that the Autobots find the Omega Lock and the four Cyber Planet Keys to save Cybertron and the universe. Later, the Cybertron Transformers learned from Primus himself that destroying Unicron resulted in an imbalance between good (Primus, who still existed) and evil (Unicron, who was gone); this imbalance factored into the creation of the black hole, known as the Unicron Singularity in American fiction or the Grand Black Hole in Japan. His scattered pieces was absorbed by Megatron giving Megatron dark powers and causing him to look like Unicron.
However, the Japanese equivalent, Galaxy Force, made several scattered references to Unicron, as the Japanese producers for the series decided not to have Galaxy Force follow on from the events of Micron Lengend (the Japanese equivalent of Armada) and Super Link (the Japanese equivalent of Energon).
The toy of Unicron in the Cybertron series is the size of a deluxe class Transformer toy and transforms into a Cybertronian tank instead of a planet. This portrayal of Unicron is consistent with his appearance in the Cybertron strip in the Hasbro Club Collector's comic where he is portrayed at around the same size as his foes Sentinel Maximus and Omega Prime.
Although Dreamwave Productions' Unicron Trilogy comics were cut short halfway through their Transformers: Energon series, they were able to establish a very important piece of information that would be used to shape Unicron's story in future fiction. The Armada comic established that its version of Unicron did not merely consume worlds and seek the destruction of the singular universe - it moved from universe to universe, throughout the entire multiverse, destroying entire realities and moving on to the next until all of causality and existence was completely obliterated.
His coming in the Armada comic universe was first foreshadowed when he pulled Optimus Prime into a parallel dimension where Cybertron had been devastated. In return, Unicron sent something into our universe - the near dead Optimus Prime of the parallel universe, who warned them of Unicron's coming before dying. Subsequently Unicron sent his Heralds - alternates of the Generation 1 versions of Galvatron, Scourge, Thunderwing, Dirge and Bludgeon - ahead to destroy those who could oppose him (including Megatron) and capture the Mini-Con Matrix.
Galvatron was eventually killed by Megatron using the Star Saber, and the other Heralds were eventually destroyed in their captured Decepticon base by an explosion engineered by Jetfire. Unaware of his Heralds' failure, Unicron now threatened to destroy Prime, but the Mini-Cons and Jetfire managed to rescue Prime, with the power of the Mini-Con Matrix upgrading them and combining them into their Powerlinked mode. They held off Unicron long enough to escape back to their universe. Unicron then came to the Armada universe himself, where he was attacked by a combined force of Autobots and Decepticons. They distracted him long enough for the Mini-Cons to access the power of the Mini-Con Matrix and destroy the Chaos-Bringer. Here Unicron never even transformed to robot mode.
Unicron survived, but his body was crippled and he no longer had the power to transform or even move. He was forced to employ servants to do his bidding: Alpha Q and the Terrorcons, who were disgruntled former Decepticons upgraded by Unicron in return for harvesting enough Energon to repower him. While they attacked Earth, a rich source of Energon, Unicron sent his four Horsemen - Rhinox, Airazor, Terrorsaur and Cheetor, absorbed by Unicron in the previous battle - against Cybertron, devastating much of it before being stopped by Optimus Prime. Many of the latter Energon stories were set inside Unicron himself as Megatron, whose Spark had also survived the previous battle, attempted to convince Prime to resurrect him in a new body, with the planet eater seemingly unaware of their actions.
Alpha Q showed signs of rebelling against Unicron, and Prime prepared to fight back from inside Unicron. However, the series was canceled before these plot threads could come to fruition. Writer Simon Furman revealed that a future storyline of the Energon comic would have included another attack by Unicron, had the series continued.
The Transformers club comic has further developed Unicron's story for the Cybertron era, attempting to fill in the plot holes. Clarification states that Primus' chosen task in Energon was to imprison and burn away Unicron's disembodied spark within a fledgling sun. This sun was the one that was born to save Alpha-Q's world. Unfortunately, Megatron's spark, also inside, interfered and the sun collapsed, trapping Unicron's spark inside (bridging it between other universes). The black hole was born, and Megatron was freed. He used pieces of Unicron to remake his body, as well as revive Starscream, his most loyal subject. The black hole itself has begun to devour space and time, unravelling historical events and building new ones. This is the reason for the "errors" in the Cybertron animated series, as it is following a constantly reshaping universe.
A new Unicron figure was released at the end of the Cybertron toy line as a Deluxe-class figure with a tank-like alternate mode. Although the character did not in Transformers; Cybertron or its Japanese equivalent Transformers: Galaxy Force, the Hasbro Club comic served to introduce this new version of the Chaos-Bringer. In this story, the black hole contains Unicron's essence and also links him simultaneously to all Cybertrons across the Multiverse giving him the potential to wipe out Primus in one fell swoop. This course is currently being held at bay by Transformers from across the Multiverse, usually consisting of characters derived from Convention and Club exclusives as well as Cybertron figures that play no role in the television series. In one issue, Soundwave was dispatched to Cybertron after Ramjet and Nemesis Prime's failure. He tosses the Dead Matrix into the black hole, releasing Unicron's spark which quickly overtakes a nearby world, converting its inhabitants into savage maniacs. With the destruction of the planet his body is reborn as a normal sized Transformer.
When Unicron eventually attacked Cybertron in the midst of the chaos caused by a Mini-Con civil war, Sentinel Maximus and Omega Prime fought him off with the help of their allies. In the end Unicron was driven off badly wounded again, this time by Primus himself.
Unicron appears in a flashback in The Coming Storm.
Unicron again appeared as a character in the Transformers: Universe line, seemingly the same Unicron as seen in Armada. This time he was able to physically eat planets like his G1 self. Set after Beast Wars and Beast Machines, and his defeat by the Wreckers, he gathered Transformers from across different realities to create an army. These Transformers were forced to fight inside Unicron, where he feasted on both the excess Energon they gave off and the Sparks of the losers. In response to this, Primus and Alpha Trion resurrected and reformatted Optimus Primal to lead the fight against the Unicron. After freeing Unicron's captives, the Chaos-Bringer gathered an army of his own, dubbed "the Decepticons", to fight against Primus, which was led by Razorclaw, an alternate version of Tigerhawk, and consisted of alternate versions of Obsidian, Tankor and Reptilion.
Although the end of Universe did not provide a proper conclusion to the storyline, the Cybertron Club Comic would offered a possible ending. It suggested that when Optimus Prime would have been called to another dimension to fight Unicron's heralds, he would have reflected back on the final battle between Primus' forces and Unicron's army - where Unicron would have suddenly disappeared, his existence ended by the black hole created by his defeat in Transformers: Energon.
Across the multiverse
Although many of the official television and comics appearance of Unicron appear to present separate and distinct incarnations of the character, some fans and writers have attempted to present an interpretation of the sources that ties all the versions of Unicron together into a single continuity. They posit that across the multiverse, in all realities, there is only one singular Unicron who travels from dimension to dimension. Likewise, Primus is also a "multiversal singularity", but while Unicron is limited in this ability, and can only exist in one reality at a time, travelling between them, Primus co-exists in all realities simultaneously.
This concept began with the release of a series of Transformers: Armada trading cards by Fleer. The biography printed on Unicron's card presented him to be one of two heralds created by the Allspark to explore the newly-birthed universe. Inspired by his Marvel Comics origin, the other herald was Primus, and the brothers set about this task, until they came upon a region of space teeming with pure Energon. Unicron wanted this power for himself, and cut Primus down before he could report it to the Allspark, casting his brother's body into the orbit of a nearby star. And so Unicron went on to become the engine of destruction that menaced the universe in recent years.
Not long after this, the publication of Transformers: The Ultimate Guide by Dorling Kindersley cemented this notion. Writer Simon Furman incorporated the various aspects of the Dreamwave Comics story, some elements of the Fleer storyline and his original Marvel Comics origin to create what is now essentially the "definitive" origin for Unicron. In this version of events, Unicron and Primus were again twin heralds, giant metal planetoids created by the "One", who were sent to explore the universe. But Unicron was an imperfect being and turned to evil, adapting his form to transform into a giant robot. To battle him, The One gave Primus this power also, but Primus opted to remain in planet mode, and passed the transforming abilities on to thirteen robots that he created from himself; the first Transformers. One of the thirteen turned on Primus and sided with Unicron, however, and the war culminated in a battle that saw Unicron and this traitor, the "Fallen", sucked through a black hole into another universe.
This new origin is part of the G1 timeline laid down by the Ultimate Guide, which is apparently being taken as the "official" G1 timeline for future projects that require it. This means that canonically, there is only one Unicron who has travelled from universe to universe across all the assorted Transformers continuities. This interpretation of the character is evidenced by the parallel universe spanning Transformers: Universe toyline and convention-exclusive comic books — in which the singular Unicron captured Transformers from various alternate realities and pitted them against each other, feeding off the energies released — and the Transformers: Cybertron comic strip in the Transformers Collectors' Club fan magazine, which depicts Unicron's actions in the various realities in a chronological order and claims that Cybertron is the stable heart of the Multiverse.
The idea of a singular Unicron and Primus remains the official take on the subject, despite any contradictions in other official Transformers fiction.
Unicron's size is never specified in any canon materials, aside from the vague term "planet size". In Transformers: The Movie, Unicron's height appears to be anywhere from several kilometers (as when handling Galvatron) to several hundred kilometers (as when attacking and destroying Lithone and Cybertron's moons, and attacking Cybertron). A planet-mode diameter of 1000 km has been suggested[who?]  and robot-mode dimensions would follow from that estimate, provided that there is no change in size (compression or expansion) common among so many Transformers. In fact, one scene in the movie shows Jazz driving out of one of Unicron's eyes, just small enough to fit through them, though in another scene the Quintesson ship Hot Rod arrived is tiny compared with the eye. Unicron is also small enough to stand on Cybertron's surface. In season 3, it is shown that the eyes from Metroplex and Trypticon (both city-sized Transformers) are the perfect size to use as replacement parts when Unicron orders the ghost of Starscream to steal them. However later in the episode when Trypticon moves Unicron's head, the head is larger than Trypticon's entire body. (Note: However, the eyes could be only small components for his Optic Sensors to be reformed and/ or completed.) In the storyline "The Ultimate Doom", Cybertron appeared to be smaller than Earth's own moon (and by extension, this would indicate Lithone would be too small to be a planet), making Unicron's dimensions in the cartoon harder to define.
The comic version of Unicron may be far larger. In the first issue of Marvel Comics Generation One Transformers comic, Cybertron is said to be around the size of Saturn (which has a diameter of roughly 120,000 km at the equator). As Unicron's planet mode is seen to be as large as Cybertron (if not larger) in the comics, this would suggest a diameter of 120,000+ km. The Dreamwave equivalent of Unicron may be the same size, as the Cybertron of the Dreamwave universe was also said to be the size of Saturn.
- Generation 1 Unicron (unreleased)
- A prototype was created for a Unicron toy as far back as 1986, but owing to cost concerns it never made it into production.
- Beast Wars Neo Unicron (unreleased)
- A giant, top heavy Unicron toy with a "shell" type transformation intended for release in Japan circa 2000, which exists only as a prototype.
- Armada Unicron with Dead End (2003)
- The Armada figure came with its own Mini-Con, which transforms into a cannon-equipped 'moon' to Unicron's 'planet', looking very similar to the Death Star of Star Wars fame. At various points in production, Unicron's Mini-Con was originally going to be called Nebulon, the name of the homeworld of the Headmaster, Targetmaster and Powermaster partners, and also Gobotron, the homeworld of the Transformers' competitive toyline in the 80's, the Go-Bots. Designer Aaron Archer did not want such a historical action figure to be overshadowed by a Go-Bots pun, so the name was changed to Dead End, re-using a name of one of the original Stunticons. A multitude of these Mini-Cons were featured in the Armada cartoon, although they were portrayed simply as non-transforming internal defensive "laser pods," instead of actual Mini-Cons.
- This toy was voted the 52nd top toy released in the last 10 years by Toyfare Magazine. 
- Energon Unicron with Dead End (2004)
- A redeco of the Armada toy.
- Energon McDonalds Unicron (2004)
- Given away as a Happy Meal toy in Europe and Australia.
- Cybertron Deluxe Unicron
- A Deluxe size figure. The figure was packaged on a Decepticon cardback, and that the character's profile in the Transformers Collectors' Club magazine also included a Decepticon symbol. The actual story featuring the character, however, continued to present him as unaffiliated, serving only his own ends. In line with this, the toy lacks a faction symbol - a rare but not unheard of occurrence in the Transformers line, with examples including Micromasters, the Generation 2 Go-Bots, Cybertron Safeguard, SDCC exclusive Skywarp, and movie Armorhide).
- Titanium 3 inch Unicron
- A three-inch tall Decepticon which doesn't transform. It is packaged holding one of Cybertron's moons.
- Robot Heroes Optimus Prime and Unicron
- Unicron is again sold as a Decepticon in this two-pack.
- Universe Unicron with Dead End (2008)
- A Toys "R" Us exclusive, it is a repackage of the Armada Toy.
- Transformers 2010 Unicron (2010) (unreleased)
- A redeco and remold of the Armada Unicron figure to be released in late 2010 as part of Takara Tomy's "Transformers 2010" promotion, which celebrates the year in which the third season of The Transformers was set in Japan. Designed to resemble Unicron as seen in The Transformers: The Movie, pre-release photos issued by Takara Tomy show a new head and changes to the molding of the torso, as well as deco based on his movie appearance. He retains the Mini-Con partner.
- ↑ The solitary exception to Unicron's presentation as an unaffiliated entity is his Transformers: Cybertron action figure, which is packaged on a Decepticon card - the fiction associated with the toy continues to present him as unaffiliated, serving only his own agenda, while the expanded biography printed by the Transformers Collectors Club gives him a Decepticon symbol. There is confusion as to whether his Transformers: Titanium figure is sold as a Decepticon or not - while the figure features a Decepticon display base while the biography printed on the toy's package states that he has no allegiance save to himself.
- ↑ "Unicron at". Unicron.com. Retrieved 2010-04-27.
- ↑ "Transformers Generation 2 Episode 1 Part 1/3". YouTube. Retrieved 2010-04-27.
- ↑ bwtf.com: Ben's World of Transformers (Beast Wars Neo)
- ↑ TFormers.com. "Deluxe Unicron Prototype Images Transformers". Tformers.com. Retrieved 2010-04-27.
- ↑ 6.0 6.1 "2000 Meters per Pixel". Merzo.net. Retrieved 2010-04-27.
- ↑ "UnicronPage". Transformersontheshelf.com. Retrieved 2010-04-27.
- ↑ "Unicron (2003) - Chaos Bringer". www.tfu.info. Retrieved 2010-04-27.
- ↑ Toyfare Magazine issue #122
- ↑ "Unicron (2004) - Chaos Bringer". www.tfu.info. Retrieved 2010-04-27.
- ↑ TRANSFORMERS CYBERTRON Deluxe Class: UNICRON Figure- Product Detail
- ↑ TRANSFORMERS TITANIUM SERIES Die-Cast UNICRON Figure- Product Detail
- ↑ Transformers Robot Heroes: Optimus Prime And Unicron- Product Detail
- ↑ Takara Tomy - Unicron
- Unicron at the Internet Movie Database
- Beast Wars Neo Unicron Prototype
- Unicron at TFWIKI.Net, the Transformers Wiki