Melzalgald was one of the Dark Matter Thieves, a group of alien pirates travelling across space. He was one of Boros' strongest warriors and was tasked with protecting the ship, eliminating any unfamiliar life forms in his sight. After the destruction of A-City Melzalgald was engaged in battle by Iaian, though the hero was significantly outmatched and quickly lost his arm. Soon, Atomic Samurai, Bang, Metal Bat, and Pri-Pri-Prisoner arrived to fight the hostile alien. After a long fight which initially seemed hopeless, Metal Bat discovered Melzalgald's weakness (the small marbles contained within each of his heads), eventually leading the heroes to victory and the alien's death.