Brainiac

Brainiac is an artificial life form, created by the computer tyrants of Colu. Seeking to seize control of the planet as a launching point for interplanetary conquest (think Microsoft), the computer tyrants created Brainiac, a computer in the form of one of the natives. Green skinned with green eyes, Brainiac appeared like all Coluans with the exception that he wore a sensory net on his head that looked suspiciously like a hair net. Brainiac's greatest weapon was his massive intellect and his lack of emotion, making him merciless. After his masters were overthrown by the people of Colu, Brainiac left Colu and began a campaign of terror across the universe.

During the waning days of the planet Krypton, Brainiac used the power of his space craft to shrink the city of Kandor and stick it in a bottle. Later, he came into conflict with the Man of Steel, Superman, when he tried to do the same to Metropolis. Superman stopped him and recovered the bottle containing the Kryptonian city, placing it in his Fortress of Solitude.

Brainiac became one of Superman's greatest foes, clashing with the last son of Krypton time and again. Prior to the Crisis on Infinite Earths, Brainiac relocated into a more metallic body and travelled the universe in a ship shaped like his head.

The post-Crisis version of Brainiac was also from the planet Colu. A criminal with great mental abilities, Querl Dox, was sentenced to death, being disintergrated. His mind lived on without a body, until he took over the body of a sideshow mentalist. In this new body, he fought Superman and later was grown a new body, which looked very much like his former body by the scientists of Lexcorp. Brainiac, later became the master of Warworld, after the defeat of its former master at the hands of Superman.