Mega

Mega is a planet some where in outer space. Millions of inhabitants were all killed in cataclysmic atomic wars, however one man survived, the brilliant Professor Heckla, who built the android Brainiac, to travel to Earth and capture specimens from every species on Earth, so that Mega can be repopulated. Superman stops Brainiac, but time and time again Brainiac returned to challenge the Man of Steel and the rest of the Superfriends.

Reference
The New Adventures of Superman
 * Superman meets Brainiac
 * The Return of Brainiac