Gallaxhar

Gallaxhar is the main antagonist of the 2009 Dreamworks movie Monsters vs Aliens.

He is a four-eyed, multi-limbed blue alien whose main goal is to retrieve a powerful cosmic substance called "Quantonium" from Susan, who was accidentally hit by an asteroid containing it and, in turn, grew huge due to it being a radioactive mineral. He lives in a huge UFO and utilizes many alien weapons, including giant, nearly-indestructible robots in his attack on earth. He also cloned himself to create a huge army to take over Earth. He was killed when his ship self-destructed.

He said himself that he destroyed his own home planet for no apparent reason but to test his weaponry.