Brainiac is a fictional character, a supervillain that appears in comic books published by DC Comics. The character first appeared in Action Comics #242 (July 1958), and was created by Otto Binder and Al Plastino.
An extraterrestrial android (in most incarnations), Brainiac is a principal foe of Superman, and is responsible for shrinking and stealing Kandor, the capital city of Superman's home planet Krypton. Due to complex storylines involving time travel, cloning, and revisions of DC's continuity, several variations of Brainiac have appeared. Most incarnations of Brainiac depict him as a green-skinned being in humanoid form. He is bald, except for a set of diodes protruding from his skull.
The character is the origin of the informal word which means "genius". The name itself is a portmanteau of the words brain and maniac, with influence from ENIAC, the name of an early computer. In 2009, Brainiac was ranked as IGN's 17th Greatest Comic Book Villain of All Time.