Melzalgald is a villain from One Punch Man. A member of the Dark Matter Thieves, Melzalgald is a disturbing alien who has multiple heads, each with it's own personality and is capable of instant regeneration.
When the Dark Matter Thieves first arrive at Earth, Melzalgald is initially tasked with protecting the outside of their ship. He first appears killing the Skyfolk, then goes on to kill the survivors of their attack. He is initially confronted by the A-Class hero Iaian, who saves two survivors from his attack. Iaian slashes Melzalgald, but he regenerates and strikes back, making Iaian lose one of his arms. Just as Iaian is about to be killed by Melzalgald, his master and S-Class hero Atomic Samurai appears and saves him, being quickly joined by three other S-Class heroes: Bang, Metal Bat and Puri-Puri Prisoner.
The four heroes attack Melzalgald constantly, but it has no effect on him due to his healing ability. Annoyed, Melzalgald sends one of the heads back to the ship, but it is intercepted by Metal Bat, who eventually finds the monster's weak point: a floating marble which instantly kills one head when destroyed. Geluganshp telepathically contacts Melzalgald and tells him to return to the ship, but since he is unable to he tells Geluganshp to aim the ship's cannons near his position to dispose of the heroes, however the cannon's shells are all intercepted by Tatsumaki, who telekinetically shots the shells back at the ship.
The heroes continue their attack and kill the heads one by one. As Bang destroys the penultimate marble, Melzalgald retaliates, knocking Bang through some concrete walls. Realizing the humans could be killed in one hit, he decides to focus on the offense, concentrating his attacks on Atomic Samurai. However, Bang escaped from the previous attack, and as Melzalgald gets distracted Atomic Samurai slashes him. As he once again starts regenerating, Bang grabs the last marble and destroys it, killing Melzalgald for good.