** Spoiler Alert for Spiderverse
If you have already seen Across the Spiderverse, you know the movie has two main antagonost: Spider-Man 2099 and the Spot. While the intentions and motives for Spider-Man 2099 can be debated, the Spot's cannot. He is a villian who is motivated by revenge against Miles Morales.
But his comic book origins is a bit more... well corny. If you read Spider-Man in the 80's, you know Spidey's rogue gallery has some goofy characters in it. For every Green Goblin there is a Red Rocket or a Trapster, or a White Rabbit. And to be honest, the Spot fits right in with those corny villians. So lets take a trip all the way to 198 and Spectacular Spider Man 97 in December of 1984 where we get a chance to see the unamed character who would become the Spot in Spectacular Spider Man #98 in January of 1985!
As he is working for the Kingpin who is looking to somehow harness the powers of superhero Cloak, our soon to be Spot is a scientist. And is often the case, sometimes ambition outweights smarts which leads to an experiment that he cannot take back.
By the time we move onto issue 98, we are gonna get are full reveal of the Spot and on the scientist in question, ..... As he is looking into the powers of Cloak after a pep talk from the Kingpin, Dr. Jonathan Ohnn is transported across dmensions and can use these "spots" to move inbetween time and space. I am not 100% sure if the science checks out but, "because comics" always explains any plot holes.
Again, if you read comics in this period, especially Spider-Man, a villian would be introduced, give Spider-Man a hard time for like an issue, maybe two, and then would be disposed of rather quickly in the next issue. Its like people who feuded with Hulk Hogan. They'd be presented as credible, beat up Hulk Hogan, have a match where Hogan looks dead but he Hulks up and boot to face, leg drop, 3 count. Spider-Man at this time is no different. This book their initial fight the Spot gets the best of Spider-Man and then takes off- which leads to their blowoff match in Peter Parker the Spectacular Spider Man #100