Kilobot

Kilobot is the main antagonist of the second season of Cubix: Robots for Everyone.

He is the most intelligent and powerful of Dr. K's robots and has the power to mimic the techniques and attributes of robots it absorbs said process puts the robots in a near-death coma that's implied to kill them, if not treated in time. The goal he was given by Dr. K was to destroy Cubix, however he goes out of his way to cause as much destruction and harm towards anyway that just so happens to be there making him more evil by default.

In the episode "Roller Koaster", he attacked Cubix while he was at an amusement park riding a roller coaster and delibaretly knocked the rails off the roller coasters while fighting Cubix causing the death of many children that Cubix and the gang failed to save.