Jonathan Ohnn was working as a research scientist on behalf of Wilson Fisk, the Kingpin of Crime. The Kingpin hoped to create a new super-powered henchman to replace the Answer, who was killed after an encounter with Dagger. Ohnn turned his attention to Dagger's partner, Cloak, and used his machines to duplicate Cloak's power to open transdimensional portals. Curious, Ohnn stepped into the portal as the machines shorted out and, as a result, found himself transported to the so-called Spotted Dimension, a crossroads dimension. When he used a portal back to his laboratory, Ohnn found himself covered in spots that were actually portable space warps.
At the same time, the heroes Spider-Man and Black Cat were investigating Fisk's building. Calling himself the Spot, Ohnn confronted the heroes and initially managed to thwart them. But when Spider-Man returned later, the Spot battled him again, only to be soundly defeated and traumatized into thinking he could never be a supervillain.
After many years, however, Ohnn reappeared as the Spot, teaming up with the lesser-regarded villains Grizzly, the Gibbon, and Kangaroo. The Spot hoped to join the three in a successful crime spree, forming the Spider-Man Revenge Squad. Spider-Man actually threw the fight in their encounter, hoping to bolster the resolve of Grizzly and the Gibbon in becoming "good guys" instead. He must have been successful, as the two subsequently turned on their teammates, defeating the Spot and the Kangaroo.
At one point, the Spot was captured by the organization known as the Gideon Trust, who forcibly used Ohnn to open a portal to the Negative Zone dimension. The Gideon Trust hoped to investigate and exploit the natural resources of the Zone for their own purposes. The Fantastic Four were trapped in the Zone and they defeated the agents of the Gideon Trust before using the Spot’s portal to return to Earth. In the process, Ohnn seemed to have died.
In fact, the Spot survived and at some point was remanded to the Cage, an internment facility for superhumans. There, he was conscripted to form an unlikely crew with Hypno-Hustler, Rocket Racer, and Big Ben, all led by the sadistic Tombstone. In this manner, the crew was able to survive the challenges of prison, although Ohnn turned the tables on Tombstone, snitching on his activities in exchange for a parole. Even so, Tombstone used the Spot to arrange an escape from prison. He thanked the Spot for his help by killing him, snapping his neck.
However, the Spot reappeared months later, contacting his close associate, Slyde, and arranging a meeting. Both were upset at the reports of the Hydra capturing or killing lesser-known supervillains. However, when the Spot arrived, he found a brainwashed Elektra and ninja of the Hand standing over Slyde’s dead body, and he was quickly captured as well. The Spot and Slyde were resurrected by the Hand to join Hydra’s army of superhumans, all orchestrated by the Gorgon. The Spot was among the sixty to seventy agents led by Elektra against S.H.I.E.L.D., but he was felled by S.H.I.E.L.D.’s ally, Wolverine.