Headmasters are a sub-group of characters from the Transformers meta-series, distinguished by their ability to detach their heads when transforming into their alternate modes, with the heads then transforming themselves into a humanoid form. However, this concept was taken in several different directions across the different Transformers universes.
The details of the binary-bonding process have never been fully explained. As the end result, though, the human or Nebulan is able to wear a special armor, which gives him/her a telepathic link with the Transformer, and also allows him/her to transform into a mechanical object that can be used by the Transformer. In the latest IDW Publishing version, the transforming technology is built into the Nebulans themselves.
When connected with each other, the human or Nebulan and the Transformer essentially share a single mind and can work together seamlessly, but when separated from each other, both retain their individual minds and bodies. This allows for greater cooperation, and with twice the experience, a better understanding of possible combat or other dangerous situations. The binary-bonding process does not damage the body of either party, and both parties are able to carry on with their normal lives, but it does generate a permanent, irreversible bond between their minds.
Most of the organic creatures that underwent the binary-bonding process in the Transformers TV show and comic were Nebulans. The most notable exception is the human Spike Witwicky, who is binary-bonded to Cerebros, who is in turn part of Fortress Maximus. In the TV show, Spike's son Daniel was also binary-bonded to the female Autobot Arcee, but neither Daniel nor Arcee ever appeared in the American comic. (In the American Transformers: Headmasters mini-series, an Autobot resembling Arcee in convertible mode was shown in an Autobot convoy, but never identified as her.)
With the battle superiority of the Autobot Headmasters evident, the Decepticons were forced to flee during the next battle. The Hive, however, had been observing events, and used their machines to bring the Decepticons to them, where they struck the same deal. The heads of the animal Transformers were offered up to the Hive, who turned them into exosuits, once again giving themselves strong bodies. Lord Zarak, meanwhile, used the process to modify the Hive's entire subterranean city to a colossal super robot that he dubbed Scorponok. With Scorponok's power, the Decepticons obtained the Plasma Energy Chamber key and returned to Cybertron.
Spike, meanwhile, had concocted a plan to counter Scorponok's power. The remaining Autobot, Cerebros - a pacifist who refused to undergo the Headmaster process - had located the city that had formerly belonged to the Hive, before they developed their mental powers and went underground. Using the Hive's machines, Spike reconstructed the city, Cerebros, and himself into another new super robot - the mighty Fortress Maximus. Spike became Cerebros's Headmaster partner, and Cerebros in turn then transformed into Maximus's head. Arriving on Cybertron, Maximus and Scorponok battled as the Plasma Energy Chamber threatened to overload Earth's sun. Spike and the Nebulans were able to save the planet, however, by draining off the excess solar energy and re-energising Cybertron, restoring its golden age.
As this marked the end of the American Transformers series, the 1988 characters never appeared in animated form in the U.S. except in toy commercials.
In this version of events, there are no Nebulans involved. Millions of years ago, during the wars on Cybertron, many Autobots fled the planet to escape the conflict. One such group was a collection of diminutive Transformers, led by the robot called Fortress (the Japanese equivalent of Cerebros), who eventually settled on the planet Master. However, Master proved to be a world of harsh environment, and so, in order to survive, the small Transformers constructed larger, lifeless bodies called Transtectors, and modified their forms so that they could transform into heads, in order to attach to and control the Transtectors. Chromedome, Brainstorm, Hardhead, Highbrow, Weirdwolf, Mindwipe, and Skullcruncher underwent this process, but soon the latter three turned to the side of evil under the leadership of Scorponok (Lord Zarak), who made contact with Galvatron, and joined with him in his renewed attack on Cybertron in 2011.
Using the power of the mighty weapon, the Master Sword, Fortress is able to combine with the Headmasters' battle ship, Maximus, to form Fortress Maximus. Scorponok also had a massive Transtector constructed for himself, dubbed Mega Zarak (Scorponok), harnessing the plasma energy released from the destruction of Cybertron he had engineered to power it.
With a cry of "Head On!", the Headmasters attach to their Transtectors, meters in their chest displaying their energy readings. They possess incredible amounts of energy within their bodies, which can be used in various ways - by swapping from Transtector to Transtector with their fellows, in a process called "Cross Head On!" they can summon up this energy to recharge themselves, and by linking hands in a ring, their energies can be united together into one mighty force and unleashed in numerous ways, such as force bolts, recharging beams, or as an aura that surrounds them, allowing them to spin in a destructive circle.
Prior to 2005, Headmasters was only available in its original format in the East, with Laserdisc and DVD releases. Most fans who had seen the series did so through the infamous "Singapore dubs" - an atrociously badly dubbed English-language version of the show from Hong Kong found airing in Asia in the early 1990s, which was bootlegged many times over to be spread around. In a world first, UK-based DVD company, Metrodome Distribution Ltd released the entire series on DVD on 26th September 2005, in a dual-language format, featuring the original Japanese audio with new English subtitles, and the "Singapore dub", complete with commentary on the opening trilogy by long time fan and TF authority Chris McFeely (fan commentaries having become an easy and fairly informative pastime of recent region 2 cartoon box set releases). The DVD disks were also formatted in region 0, allowing more people the possibility of owning the series for the first time.
In Masterforce, the Headmasters are not small robots, but actually human beings who don a suit of armour and combine with a Transtector, given the new title of "Headmaster Jr."'s. Consequently, as they do not represent their American counterparts, they are known by completely different names - Nightbeat is Minerva, Siren is Go Shooter, Hosehead is Cab, Fangry is Wilder, Horri-Bull is Bullhorn and Squeezeplay is Cancer, each of them a human teenager recruited by the Autobots or Decepticons in the battle. Additionally, Fortress Maximus's younger brother, Grand Maximus (exclusive to Japan) makes an appearance in the series, with his Headmaster component, Grand, possessing a Pretender shell. Also appearing is another Japanese exclusive, Black Zarak - a brainwashed Zarak with a rebuilt Transtector.
Lord Zarak, however, was not. In an attempt to have the Autobots removed from the planet, his forces contacted Cybertron, calling to Nebulos a contingent of Decepticons led by Scorponok. Galen's group attempted to remote-control the decapitated Autobot bodies themselves, but when that met with failure, Arcana and Fortress Maximus worked together to create a process called "Binary-bonding" - the engineering of the Nebulan's bodies into transforming cybernetic forms, allowing them to transform into heads and become masters of the Autobots' bodies. Thus, the Headmasters were born, and they defeated Scorponok's Decepticons soundly, forcing them into an alliance with Lord Zarak and his forces, becoming Headmasters themselves. The Autobot Headmasters were defeated and captured, but Lord Zarak slowly began to feel the malicious, robotic emotions of Scorponok overtaking his mind, worsening with each combination. In a final attempt to save his planet before the inhumanity overcame him, he freed Galen and the other Nebulans, who then followed a distress signal emanating from the Autobots on Earth. The Decepticons pursued them, leaving Nebulos, as Zarak had wished.
In transit to Earth aboard their starship, the Steelhaven, Brainstorm, Chromedome and Galen disassembled and reconstructed Fortress Maximus to increase his fighting power. Now, an additional Autobot drone, Cerebros, had been incorporated into his design - rather than directly forming Maximus's head, as he had done before, Galen became Cerebros's head, and Cerebros formed that of Maximus. However, soon after their arrival on Earth, the Headmasters were pulled into another battle with the Decepticons inside Mount Saint Hillary, the volcano that had formerly housed the Ark, where Galen was killed by an avalanche while saving the life of Spike Witwicky. Using Galen's helmet, Spike took control of Fortress Maximus and routed the Decepticons, after which he accepted the other Headmasters' offer to binary bond him to Fortress Maximus, taking Galen's place in the combination, in order to save his brother, Buster, who had been captured by the Decepticons.
While Fortress Maximus's team joined with the other Earthbound Autobots, Zarak bolstered his forces with the addition of Fangry, Squeezeplay and Horri-Bull, although it was never clearly established where these Decepticons or Nebulans came from. It would be some time before the Autobot counterparts to this trio were introduced, and even when they were, no indication was given that they had undergone the Headmasters process. In the UK comics, however, they were indeed shown to be Headmasters.
Fortress Maximus eventually succeeded in saving Buster during the battle for the power of the Underbase, and Spike chose to give up the role, returning his armour and helmet to Optimus Prime and leaving Maximus's body stored on the Ark. However, when he came under attack from the Decepticon Pretender Beasts, Snarler and Carnivac, it became apparent that he and Maximus had bonded more deeply than anyone had realised, as his body arrived to combine with Spike and fend off the Pretenders. Despite this, Spike chose to return Maximus's body to the Ark, where it remained until the craft was crashed in 1991 by the Autobot medic, Ratchet, during the clash between Megatron and Galvatron. Spike was drawn to the crash site by Fortress Maximus's mental urging, and recombined with him once again to battle the deranged Galvatron, eventually defeating him by burying him in ice.
Later, when Spike had his revelation, the more familiar Headmaster concept came into play - the idea of two minds inhabiting one body, as Fortress Maximus's voice spoke within Spike's head and could urge him into actions. Although this was utilised by Bob Budiansky at the end of his run, it was in fact consistently how Simon Furman had portrayed the Headmasters in the UK comics, and carried the idea over into the US comics when he began to write them. Furman's first Headmasters story, "Worlds Apart", even seemed to reconcile the two contradictory ideas - that the process was intended to create a singular mind, but had malfunctioned, leaving two minds in one body with the Nebulan in ultimate control.
Interestingly, however, Furman would also take Scorponok and Lord Zarak in a different direction. Where with other Transformers, he clearly kept the Nebulan and Transformer minds distinct, in the case of Scorponok, Lord Zarak's personality appeared to eventually completely supplant Scorponok's own - although he would refer to himself as Scorponok, in his private thoughts, he considered himself only to be Zarak. This led to the fears and doubts which eventually resulted in his alliance with Optimus Prime, and, in his attempt at redemption, he attacked Unicron with his bare hands and was melted by the chaos-bringer's fire breath.
During the main G1 series The Transformers: Escalation hints appeared that the shadowy organisation called the Machination were not all they appeared. During the series, they captured Sunstreaker and the human Hunter, completing some sort of surgery on them. It was revealed near the end of the series that not only was a mysterious, badly-damaged Decepticon behind it all, but that they had made numerous headless copies of Sunstreaker's body. In issue #2 of The Transformers: Devastation the extent of their plan was revealed, as an army of Sunstreaker clones pursued Wheeljack and Hot Rod. These clones displayed the ability to remove their own heads - who then transformed into humans. These Headmasters are more like piloted drones , controlled by their human "heads" and guided by the memories of the real Sunstreaker, rather than the fully bonded Headmasters in other continuities. When Sunstreaker helps Hunter turn into a real Headmaster after his surgery, it is accomplished via an iron maiden like chamber. The extent to which Hunter is altered is unclear, but he displays vastly improved strength, easily able to smash an adult human through a door and into the wall behind with one punch. It was also revealed that Scorponok, now reduced to a damaged head, has been guiding the Machination. In doing so, he has turned Abraham Dante, one of the human leaders of the Machination, into a Headmaster version of himself, combining with a recreated version of Scorponok's own body.2000 Japanese line, Transformers: Car Robots, Fortress Maximus's toy was repainted and released as a new character named Brave Maximus (with the Headmaster components, Brave and Plasma), and was the main focus of the final arc of the animated series. When the series was then imported to the US as Transformers: Robots in Disguise, safety regulations meant that the toy could not be released, but his involvement in the animated series remained, where his name was changed to that of his predecessor, Fortress Maximus (with the Headmaster components, The Emissary and Cerebros). The term "Headmaster" was even used in the show. 2002/2003 toyline, Transformers: Armada the figure known as Overload was identified as a Headmaster, whose head was formed by the Mini-Con, Roll-Out. However, although Overload is featured briefly in the animated series, this aspect of the character was not touched upon. He did appear more prominently in the Dreamwave comic book series. Ultra Magnus with Knock-Out, and re-released in the 2004/2005 toyline, Transformers: Energon. Although he did not feature in the animated series, the second Headmaster-style toy of the line did - Omega Supreme (although Omega Supreme, like Sideways, has a permanent head). Bulkhead's body, using it to attempt to set off a nuclear meltdown. The meltdown is stopped, and Bulkhead's body is retrieved, but Masterson escapes. He next appears in "Return of the Headmaster", where he steals Sentinel Prime's body. He is defeated by Optimus Prime, but his employer, Porter C. Powell, manages to keep him out of being arrested.
In "A Bridge Too Close", a stolen Headmaster unit is used to threaten Bulkhead into helping the Decepticons with their Space Bridge. The unit is later used by Isaac Sumdac to take control of Starscream's body.
The Headmaster unit remarkably resembled the original G1 Headmaster Transformers.