A self-made millionaire, G.B. Blackrock is the founder of both Blackrock Industries and the Neoknights. He is one of the few humans on Earth who are aware of the differences between Autobots and Decepticons. His current status is unknown.
Blackrock first became involved in the Transformers' conflict when Shockwave was watching television after defeating the Autobots and reviving the Decepticons. In a televised interview, he boasted about his new high-tech oil rig, equipped with everything from refining equipment to weapons, and designed with the help of Josie Beller, a devoted employee. Less than an hour after, before he could leave his office on the rig, Shockwave attacked, effortlessly defeating the rig's defence systems and crippling Josie in the process. Blackrock and the rest of the survivors were allowed to leave by Shockwave to serve as messengers of the Decepticons' conquest of the Earth. He promptly installed more defences at Blackrock Aerospace Plant Number One on the outskirts of Portland, including artillery and armed guards. Soundwave and Laserbeak, following files from the rig, were carried in by an unsuspecting worker, however, and were able to avoid most of the plant's outward-pointing heavy weapons. They captured the plant, and Shockwave turned it into the Decepticons' main base, intending to build a Decepticon army from the planes being assembled there by using the plant's equipment, the captured workers as slave labour, and the Creation Matrix from Optimus Prime.
Infuriated by the attacks on his plants, Blackrock began to build an anti-robot photonic cannon, catching the rebuilt Autobots' attention with news of a secret weapon. Jazz suggested that the Autobots could strike a deal with him, and after kidnapping him and taking him on a high-speed ride, Blackrock agreed to exchange fuel for Autobot protection. Before he could demonstrate the cannon, Josie, who had turned herself into Circuit Breaker, sabotaged it to force him to call her his secret weapon, and crippled Jazz, Wheeljack, Starscream, and Frenzy. Blackrock convinced her to exchange whatever debt she felt she owed him for sparing the Autobots, and she walked away.
The Blackrock-Autobot alliance began auspiciously, with the Autobots offering Blackrock a tour of the Ark. At some point, he learned to recognise some of them, and once let Bumblebee give him a ride home while he gave the Autobot information. Hopeful that they would offer him advanced technology that would make his company unbeatable, he let them use a phone tapping device that he had installed in his aerospace plant to monitor the loyalties of his workers, gave them Blackrock Gold Priority credit cards to buy gasoline from his stations, and offered information about government and Decepticon actions that his status gave him access to. He also remained in close contact with the government, attempting to convince them without much luck of the Autobot-Decepticon war and the dangers of their attempt to claim that a human, Robot Master, was in charge of all robots.
With the Decepticons refraining from overt attacks on Blackrock's property, the alliance remained quiet. When he accidentally became involved in a battle between G.I. Joe and Cobra, he managed to offer information about the Transformers to them and have them accept it. Eventually, Blaster and Goldbug, who had defected from the Autobots, used a special key he carried to get fuel from the pumps of a gas station, then asked him for information about Decepticon activities. He directed them to a crashed spaceship in northern Arizona, which happened to be the site of a major Scraplet infestation. Goldbug called him later, asking him for water to kill the Scraplets, and he had to personally escort two tanker trucks filled with water past the army blockade around the crater. In the process, Astrotrain, who had been instructed to look for rich humans with connections to Earth's energy business, planted a portable stroboscopic opticon on him.
At least one, and possibly more, of Blackrock's oil tankers were hijacked by the Decepticons. He didn't really care, boasting instead of the huge success of his new Wash and Roll car wash franchises. This somewhat unexpected development was due to Decepticon mind control, and he was snapped out of it by Buster Witwicky before he could start selling his Wash and Roll Mark II, which would have ensured that whoever drove through it remained permanently under Decepticon mind control. He pledged to take the car washes apart and sell the gas that the Decepticons had been collecting for humanitarian purposes.
Shortly afterwards, when the Throttlebots tried to get fuel at a Blackrock gas station, they found a RAAT unit waiting for them. They deduced that Blackrock's aid had become too blatant, and decided that there were likely ambushes at every gas station, although it is not known if Blackrock was pressured into placing them there. It is known that he convinced himself that he couldn't do anything in the Autobot-Decepticon struggle.
Some years later, after RAAT had been disbanded as more of a hindrance than a help in the defence of Earth, Blackrock saw a chance to reenter the struggle. He organised a small group of superhumans, including Circuit Breaker, who became the Neo-Knights. When the Decepticon Civil War broke out near New York and threatened to spill into the city itself, President George Bush personally ordered Blackrock to led his team into action. While the Neo-Knights initially threatened the Autobot-Decepticon alliance by attacking Scorponok and then Nightbeat and Optimus Prime, Blackrock eventually managed to convince Circuit Breaker of how Shockwave had created her, and she knocked him out, ending the battle. The entire group was then accidentally transported to Cybertron by Primus along with the Transformers on Earth, where the Transformers' god proved indifferent to their plight.
When Unicron attacked Cybertron, Blackrock's first reaction was to run. The Neo-Knights shamed him into trying to make a stand, however, and he managed to make Circuit Breaker distract Unicron long enough for Optimus Prime to destroy him by driving her totally insane. The Autobots then locked him and his team up with Hi Q, whose mind had merged with that of Optimus Prime, and who convinced him to break out before the Autobots left Cybertron and look for the Last Autobot. Blackrock himself was last seen on Cybertron as they located the Last Autobot, but it is likely that he was transported to Klo along with the Neo-Knights, and then returned to Earth by the Autobots.