Brainiac

The Living Computer

Origin: Brainiac was created on Krypton, Superman's home planet. When Jor-El discovered that Krypton was doomed to explode, he tried to warn the Kryptonian council of their impending doom. However, Brainiac disputed Jor-El's claims and the council dismissed Jor-El's findings. Jor-El discovered that Brainiac has actually lied to the council and was planning to save himself, leaving the Kryptonians to their doom.

A decade or two later, Brainiac approaches Earth and Superman discovers that Brainiac has been collecting knowledge of the planets and then destroying them when he is finished. Superman managed to defend Earth from Brainiac a number of times.

In Justice League, Brainiac threatens Apokolips and Darkseid must enlist the help of the Justice League to save his planet.