Megaroid

The Megaroid is a creature created by the Space Pirate leader, Dragüd. He once accidentally set on a planet with Metroids, unknowingly, and the parasites made quick work of his underlings. By studying one of the nuclei of a dead Metroid he obtained, his scientists had designed a "far more aggressive and submissive... A bioweapon surpassing the Metroids!" Before they could perfect the mind control needed to keep it docile to Pirates, it broke free on planet Liberty, drained two scientists of their life energy, and knocked over three more Pirates while escaping through an opening door.