Kara Zor-El[]
Kid Devil[]
Kilg%re[]
The Kilg%re was an electro-mechano-organic intelligence that needed electro-life to survive. It consumed its entire home planet in the Pleides sector, and then moved on into space. It was attacked by something known as Meta#sker and placed into a vibrational limbo. Somehow, it found its way to the flats near Salt Lake City on Earth. It could only be seen by people traveling at high speeds, such as an F-15 pilot or the Flash. The Flash unknowingly released it from limbo, and it followed him to S.T.A.R. Labs and took over its electrical systems. Kilg%re found the number of machines on Earth ideal for its survival, but the humans it deemed distractions and planned to destroy. It delivered an ultimatum: abandon North America by noon on May 10 or be destroyed. During a battle with the Flash in Salt Lake City, it turned out all the power in the country. Flash sought the help of Cyborg, who used the Titans' satellite to relay the message to the governments of the world to shut down all power to kill Kilg%re. This scared it out of the power grid, and it weaved a giant mechanical snake across the Utah flats, trying to complete a circuit by catching up with the cloned body of S.T.A.R. Labs' Doctor Schmitz in order to survive. However, the Flash outraced it, supposedly killing it.
Killer Croc[]
Waylon Jones is the altered human known as Killer Croc. He is a foe of Batman and is distinguished by his reptilian features, superhuman strength and unrelenting savagery. Initially, Waylon started out as just having a jaundiced pallor to his skin, but as years went by, he became more and more reptilian while also suffering from a diminished intellect. In terms of raw power, brutality and sheer ferocity, he is probably one of the Batman's most powerful adversaries.
Killer Frost (I)[]
Crystal Frost was once a scientist and lover of Professor Martin Stein until he insisted that they should part company. While working at the Mohole research station in the Arctic, Frost was locked inside of a thermo frost chamber, which gave her the powers of cryokinesis. Driven insane, she sought revenge against Stein for rejecting her and used her new-found abilities as Killer Frost to attack him. By this point, Stein was one-half of a composite being known as Firestorm. Firestorm and Killer Frost clashed on several occasions, but ultimately her own powers began slowly killing her. During a battle, Firestorm attempted to cure her, but the sudden influx of nuclear energy only accentuated her condition to the point of death.
Killer Frost (II)[]
Louise Lincoln was a scientist and an assistant to Crystal Frost. When Crystal was dying from the very powers that made her Killer Frost, Louise tried in vain to find a cure for her. Failing that, she repeated the conditions that gave Crystal her cryokinetic powers and became the second Killer Frost. Lincoln blamed Firestorm for the death of her friend and embarked upon an endless campaign to avenge Crystal Frost's death. Louise Lincoln later went on to become a member of the Injustice League, the new Secret Society of Super-Villains and the Suicide Squad.
Knockwurst[]
Knockwurst was a German terrorist and super-villain and a member of the group known as the Wurstwaffe. He assisted in a daring attack against the Pan-European Economic Conference in 1992. In attendance at the conference was the former Justice Leaguer, Ralph Dibny, aka, the Elongated Man. Ralph had his back turned when the Wurstwaffe first laid siege to the hall and was unprepared when the leader of the group smacked him in the back of the head with a sausage. Believing him unconscious, they prepared to load him into their specially-designed escape vehicle, the Wurstwagen, but Ralph surprised them and managed to shape his body into a large sling that sent the corpulent villains flying out into the street. (Elongated Man 4)
Krypto[]
Krypto is a Kryptonian animal that bears a strong resemblance to an Earth dog. He is the adoptive pet of Superman and demonstrates proportionate abilities to other Kryptonians under the solar-powered influence of a yellow sun. For a time, Krypto stayed at Lois Lane's apartment, but when the super-strong canine proved to be too unruly, he was sequestered in the Fortress of Solitude.
Krona[]
Kyle[]
Kyle was the son of the Golden Age super-villain known as the Mist. He had a younger sister named Nash. Kyle wished to uphold his father's legacy in combatting members of the Knight family, so he targeted David Knight - son of Theodore Knight, the original Starman. Kyle murdered David in cold blood. (Starman Vol 2 0) David's younger brother, Jack Knight, later avenged his brother's death by killing Kyle with the Cosmic Staff. (Starman Vol 2 3)