As in all other Sonic the Hedgehog media, Doctor Ivo Robotnik is the primary antagonist of UK-published Sonic the Comic, as well as its fanmade webcomic spin-off Sonic the Comic Online. When he first appeared, he resembled his original image from the games. From Issue 22 onwards, his image was changed to resemble his animated counterpart from Adventures of Sonic the Hedgehog. Unlike in the games, this incarnation of Robotnik succeeded in his goal of world domination and ruled the planet Mobius with an iron fist from issues 9 to 100.
Robotnik was not always a deranged, evil dictator. He used to be known as Dr. Ovi Kintobor, a thin, kindly scientist who wanted to make Mobius a world free of evil. His experiments with the Chaos Emeralds were interrupted one day by Sonic the Hedgehog (who was originally brown in this version) and Kintobor requested Sonic's help in finding a missing emerald and assisting around the lab. During a test of Kintobor's prototype anti-friction Power Sneakers, Sonic broke the sound barrier for the first time and the resulting explosion fused his spines together and turned his fur blue. The day following Sonic's transformation, Kintobor underwent a change of his own after tripping over a cable running along the lab floor whilst holding a rotten egg he had taken from the fridge. The egg smashed against the control console for his Retro-Orbital Chaos Compressor, causing the machine to malfunction and release all the negative energy contained within the Chaos Emeralds. The ROCC exploded, and when the dust settled, Ovi Kintobor was gone. In his place stood a fat, menacing and cruel man known as Ivo Robotnik. Immediately after this accident, Robotnik went into hiding and began plotting his conquest of Mobius.
Robotnik's early attempts of conquering Mobius played out much how they had in the video games. However, in STC's eighth issue, the doctor hatched a plan to send Sonic forward in time. For six months, Sonic was nowhere to be found, and the peaceful citizens of Mobius could do nothing as Robotnik's Badnik armies swarmed across the planet, enslaving whole zones and turning the animal folk into organic batteries for more Badniks. When Sonic returned after a six-month absense, he organized a group of Freedom Fighters to interfere with Robotnik's operations. Robotnik, along with his lackey Grimer, would concoct numerous schemes and build all manner of deadly robots to try and kill Sonic and destroy his resistance movement. In the run-up to Issue 100, the Freedom Fighters had managed to rally the citizens into rising up against Robotnik's dictatorship. The uprising almost failed, but thanks to the actions of Sonic and a sentient machine called the Omni-Viewer, a worldwide electromagnetic pulse swept across Mobius, destroying all of Robotnik's Badniks and crippling the foundations of his empire. Robotnik was later captured, but would escape and eventually return with new Badniks at his command, launching random attacks across Mobius in a bid to sieze power again. His attempts at reconquering the world were all met with failure, and over time these constant defeats would drive the doctor insane.
When STC's story was continued in the fanmade Sonic the Comic Online, Robotnik had been reduced to a drooling, mute lunatic who only cared about murdering Sonic. Locked away in an insane asylum, Robotnik would remain silent and still for days on end. However, he was later released by the villainous group called The Syndicate in hopes that they could unlock his knowledge and use it to further their goal of destroying Mobius. Their plans were thwarted by Sonic, but Robotnik disappeared only to be found by his former allies - the Drakon Empire - who connected the dribbling psychopath to an advanced supercomputer that allowed his surpressed consciousness to resurface. With his mind restored, Robotnik was put to work by the Drakons as the leader of an invasion force. They sent the doctor back to Mobius where he assembled armies of Badniks to wage war against the planet in the empire's name. At present, the New Robotnik War rages on, with Robotnik himself hooked up to his Egg Bastion supercomputer complex, directing his robot armies through thought alone.
As with all of his incarnations throughout the Sonic multiverse, Robotnik is a scientific genius who can build just about anything he can imagine. At times, he will take control of large mecha to battle Sonic and friends personally. There have also been occasions where he has gained cosmic power, possessing godlike abilities such as warping reality itself. These abilities have always been temporary, of course. On his own without any technological aid, Robotnik has demonstrated above-average strength. On at least one occasion, he has tried to fight Sonic hand-to-hand, and while he's too slow to strike Sonic, he has managed to smash a rock with his fist.