Lucy W. sticks to villains, as next in line we have the Kryptonite Man, one of the less used (and less memorable) among Superman‘s enemies. As for now, this glowing green goon received a single live action appearance in the Superboy tv series, and in a single episode. In here, a boy named Mike Walker and portrayed by Jay Underwood is caught in an explosion in the military facility he works in. The experiment, aimed to make Superboy immune to Kryptonite, imbues Walker with the deadly mineral, an infection that also makes him go crazy. Superboy only defeats him with the aid of a human double, immune to Kryptonite Kid‘s energy blasts. In the comics, there are two versions of this first Kryptonite Kid/Man, but none of them is called “Mike Walker”. Let’s see together.
The first Kryptonite Man was a resident of Earth-One, and he actually debuted as the Kryptonite Kid. An unnamed alien travelling through space with his dog (some sort of bulldog), he was a punk and a scoundrel, and he did pretty much whatever he wanted, taking whatever he desired. During one of his wanderings, the alien’s ship went through a cloud of Green Kryptonite, the radioactive substance released by the destruction of planet Krypton: the element penetrated the ship, and infected both the boy and his dog. Despite the heavy amount of radiation, however, they didn’t die, as their alien physiology allowed them to absorb the Kryptonite in their organism, albeit with unforeseen results: they both became green, glowing with Kryptonite radiation, and the kid could also turn everything he touched into Kryptonite. Shortly after, he landed on Earth, where he resumed doing what he always did: being a space punk with violent tendencies. Said planet had a powerful protector, however: Superboy, an invulnerable hero… who turned out to be extremely sensitive to Kryptonite. The mere presence of the mineral was nearly lethal for Superboy and the Kryptonite Kid, taking advantage of the fact the hero couldn’t even touch him, started a rampage. Eventually, however, Superboy managed to catch both him and his dog thanks to a makeshift armor made of lead, that could stop Kryptonite’s radiations. This first defeat was the beginning of a feud between the two young aliens, and they clashed several other times: years passed, Superboy became Superman, and the Kryptonite Kid became the Kryptonite Man, but their enmity never ceased. Eventually, near the end of Earth-One, the Kryptonite Man was hired by Brainiac (who, in turn, was manipulated by a now malevolent Mr. Mxyzptlk) in a final battle against Superman: this time he had no restraints, and he started attacking civilians to attract the hero’s attention. During the mayhem, Superman’s dog, Krypto, attacked the Kryptonite Man biting him at the throat. Albeit dying for the radiations, Krypto never let go, so the two enemies died together, killing themselves in a deadly struggle. Their reality didn’t live much longer.
After the end of Earth-One, the Kryptonite Man’s story was recreated completely for New Earth. This time, he was a human scientist, K. Russell Abernathy, born and raised in Metropolis. Researching an alternative power source, Abernathy collected samples of Kryptonian elements from Superman’s house, the Fortress of Solitude, making experiments to harness its power as the ultimate green energy. He used monkeys as test subjects to understand whether the radiation was dangerous for living beings or not, but he had to change the disposition of his laboratory when the Daily Planet, the newspaper he had chosen for an interview aimed to promote his work, sent to him its top reporter, Lois Lane, who Abernathy knew was hostile to animal lab testing. The lab appeared very different from what it used to be with all the monkeys hidden from view, and for the sake of appearance Abernathy even neglected security. As soon as Lane was gone, Abernathy came back to his work… but the experimental isotope enhancer he had built overloaded, having been active for the entire duration of the interview, and it exploded… fully investing the scientist, who wasn’t protected by the usual lead barrier. The amount of radiation, however, didn’t kill Abernathy, rather he was transformed on a cellular level, with his organism being imbued with Kryptonite. Not only the radiation poisoning had affected the scientist’s body, giving him a fair amount of superpowers in addition to a glowing green skin, but it also had messed up his mind, sending him into a violent rampage. Christening himself the Kryptonite Man, Abernathy walked through Metropolis destroying everything in sight with laser beams from his eyes, as if he had just come out of a B-movie. Unfortunately, Superman was missing at the time, and nobody was there to stop him. One of the witnesses of the rampage, however, was reporter Clark Kent, who immediately contacted his cousin, Supergirl. The heroine intervened and tried to stop the Kryptonite Man, only to realize she couldn’t even go near him without suffering major poisoning. After a prolonged battle, finally, Supergirl melted a truck with her heat vision, entrapping the Kryptonite Man inside of it and protecting herself from his radiations. The deranged criminal was locked in Stryker’s Island Penitentiary, but his deeds had attracted the attention of Lex Luthor: he wouldn’t have stayed in prison for long, with such an admirer.
The first Kryptonite Kid is, simply, a young punk, an alien thug who wants to do whatever he likes whenever he likes, and who doesn’t care if people get hurt while he does; K. Russell Abernathy, on the other hand, is a brilliant but ambitious scientist, who’d do anything for glory and who’s made sloppy by his arrogance. As the Kryptonite Man, they both project constantly Kryptonite radiations, which they can concentrate into powerful energy blasts either from their hands or their eyes, and they also have their strength, durability and stamina greatly enhanced; the alien Kryptonite Man is also a telepath, while the human one is able to see radiation spectra. Being one or the other, the Kryptonite Man is not an evil man per se, rather, he’s a short-tempered one who tends to lose control quite easily, with his judgement clouded by a constant radiation that keeps eroding his sanity.