Klax-Ar was a Kryptonian scientist exiled from Krypton for devoting his research to make weapons. He was placed within a sealed capsule and launched into space, Klar swore revenge upon the people of Krypton. He spent some years on another world and then found his way to Earth where Superboy lived, the only survivor of Krypton he knew of. He spun him a yarn about having destroyed Krypton with his 'sky-mine' and launched another that he said would destroy Earth. As he couldn't destroy the space-mine, Superboy pretended to agree to accompany him to space, but in fact he sent Klax-Ar off with a Superboy robot.
Years later he came into conflict with Supergirl, but was again defeated.
