dr. k: the main antagonist of the series, dr. k used to work for robixcorp, but lost his arm in a lab explosion and now as a rogue robot inventor who uses his smarts for evil. in season 1 he is 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, the kulminator and kilobot. it is unclear what happened to dr. k at the end of the series finale, though it is possible that he gave up his evil ways. voiced by maddie blaustein.