Dr. K is the main antagonist of Cubix. Dr. K used to work for RobixCorp, but lost his arm in a lab explosion and now as a rogue robot inventor uses his smarts for evil. In Season 1 he's after a substance called Solex to build the ultimate robot and destroy Bubble Town. His main robot is Kolossal, but he has his own line of evil robots such as Katastrophe, Kannon, Krab, Klawber, and Kilobot. It is unclear what happened to Dr. K at the end of the series finale. He was voiced by the late Maddie Blaustein.
All the names of his robots start with 'K'.