The Marvel Cinematic Universe has always had a focus on certain scientific types since 2008's Iron Man kicked off the decade-long "Infinity Saga" that introduced a number of new heroes, including Peter Parker/Spider-Man. Peter was something of a scientist, though in typical MCU fashion, he's come up against a few mad scientists himself.
Spider-Man has been forced to match his scientific wits against innovative tech-designers like Spider-Man: Homecoming's Phineas Mason/Tinkerer to vengeance-seeking inventors like Far From Home's Quentin Beck/Mysterio. As the comic version of the character has run into a number of mad scientists as well, there are a few who could appear in the MCU.
10 Spencer & Alistair Smythe Were The Brilliant, Revenge-Fueled Creators Of The Spider-Slayers
It was J. Jonah Jameson who originally hired scientist Spencer Smythe to design a remote-controlled Spider-Slayer to help him take out the "wall-crawling menace." However, Smythe launched his own mission of revenge against both Jameson and Spider-Man after he became terminally ill during the creation of his Spider-Slayers.
His son Alistair carried on his father's mission of revenge and created his own Spider-Slayers before he ultimately transformed himself into the Ultimate Spider-Slayer. Since Spider-Man could be a wanted man in his next MCU installment, it's possible the creators of the Spider-Slayers could make an appearance to help capture the framed hero.
9 Norton G. Fester/The Looter Was A Failed Scientist Who Was Empowered By Gas From A Meteor
While Norton G. Fester never actually passed the courses he needed to become a scientist, he never lost his drive to prove that microscopic life existed on meteorites. He was given a chance to prove this when he discovered his very own meteorite that he failed to achieve funding in order to properly study.
This led to his exposure to a gas stored within the meteorite that greatly enhanced his physical attributes. He created a costume to become the Looter in order to raise the funds needed to continue his experiments, and eventually stole other criminal's tech to incorporate into his own costume when his meteor-derived powers faded.
8 Slyde Was A Chemical Engineer Who Became A Criminal After Designing A Frictionless Chemical
Spider-Man has dealt with a number of scientists who start off as disgruntled employees that ultimately use their inventions to take revenge on the company that spurned them, which defined Jalome Beacher/Slyde, as well.
Beacher designed a special chemical compound that negated friction, which he used to coat a costume and become the criminal known as Slyde. While Beacher may not quite have reached the "mad" scientist levels yet in his quest for money and revenge, it takes a little bit of chaos to enter into battle with sliding fast and a webbing-proof costume as their only weapons.
7 Dr. Curt Connors Accidentally Transformed Himself Into The Lizard Trying To Regrow His Arm
Dr. Curt Connors initially transformed himself into the powerful villain known as The Lizard during an experiment to regrow his arm using the regenerative DNA of a lizard. Unfortunately, his new form unlocked his reptilian side, and his transformation came with a new darker personality that held a grudge against humanity.
And while Connors' transformation to the Lizard was initially accidental, he repeatedly dosed himself over the years with the formula until the mad Lizard side took complete control. Fans have seen a version of the Lizard appear in 2012's The Amazing Spider-Man franchise, but Connors has yet to appear in the MCU.
6 Dr. Vincent Stegron Willingly Transformed Himself Into Stegron, The Dinosaur Man
Connors' Lizard formula would also lead to the creation of another villain after Dr. Vincent Stegron worked with the former villain to analyze dinosaur DNA from the Savage Land. Stegron used that DNA and Connors' Lizard formula to transform himself into a powerful stegosaurus-like supervillain.
While it might be hard to incorporate Stegron into the MCU without the Lizard formula, his wouldn't be the first reimagined origin story fans have seen on the big screen, and it would be worth it just to see Spider-Man trade quips with the Dinosaur Man on the big screen.
5 Swarm Was A Nazi-Scientist Who Was Transformed Into A Being Comprised Of Irradiated Bees
Not much is known about Fritz von Meyer's past as a Nazi-scientist, though after he fled Germany, he relocated his experiments with poisonous toxins and bees to South America. There he discovered a highly intelligent colony of bees that had been mutated by an irradiated meteorite.
He created a device that awoke the bee's natural aggression in order to control them, though they turned on him and devoured his body. However, his consciousness had merged with the colony, and he returned as the seemingly unkillable Swarm with a new body comprised entirely of mutant bees.
4 Dr. Johnathon Ohnn Was Transformed Into The Spot After He Created A Portal To Another Dimension
The Spot was originally a criminal scientist named Dr. Johnathon Ohnn who was working for the Kingpin in an attempt to replicate the teleportation power of the hero known as Cloak. He was successful in temporarily accessing another dimension, though he was lost in there when he attempted to enter the unstable portal.
Ohnn was able to find his way home, but he had been covered in the dark circular portals that he could control and manipulate to access the dimension he discovered. Ohn became the criminal known as the Spot and would ultimately form the Z-list Spider-Man Revenge Squad, which would fit well in the MCU.
3 Mendell Stromm Used His Scientific Genius To Survive Death As The Robot Master
After scientist Mendell Stromm was nearly killed after a confrontation with his former research partner Norman Osborn (more on him soon), Stromm used his robotic expertise to transfer his consciousness to a robotic duplicate of his dying body to start his new artificial life as the Robot-Master.
Stromm would employ different types of robots in his missions of revenge over the years before he was destroyed. However, his original human body was revealed to have survived thanks to the untested Goblin formula in his system, and he returned in a new form during the Clone Saga as the mysterious villain known as Gaunt.
2 Norman Osborn's Strength-Enhancement Formula Transformed Him Into The Green Goblin
While Norman Osborn's original strength-enhancement serum that would become known as his Goblin formula was initially created alongside Mendell Stromm/Robot-Master, Osborn perfected the serum over the years to increase both his strength and intelligence as the Green Goblin.
However, Osborn was an accomplished engineer, chemist, and inventor whose scientific exploits led to the creation of Oscorp, and he invented the tech and weaponry he used as the Green Goblin. While fans have seen a few different versions of Norman and Green Goblin on the big screen over the years, the MCU has yet to introduce the Osborn family or any Goblins.
1 Miles Warren Perfected his Cloning Process & Genetically Modified Himself To Become The Jackal
Miles Warren/The Jackal first appeared as a professor of Peter Parker and Gwen Stacy's at Empire State University. However, his obsessive lust for his student caused a mental breakdown after the death of Gwen Stacy, which caused him to create his villainous Jackal persona.
He then perfected the cloning process in an attempt to bring Gwen Stacy back, which he also used to cause chaos in Spider-Man's life during the Clone Saga. Warren has genetically modified himself into a powerful animalistic body and cloned himself a number of times to further prove he's the next mad scientist the MCU needs to introduce.