Hero K
Device Type: Bio-Organic Robot
Function: Heavy Assault
First Appearance: Ratman Chapter 29

The Hero Killers are gigantic, humanoid creatures created by Dr. Teramishi with funds diverted from the Hero Association by the President's aide Takaki. They were created as part of Teramishi's experiments in his secret lab with the intent of making bio-weapons for profit. Basically, the Hero Killers have no free will of their own and are considered more like robots, with a central computer controlling them.

The Hero Killers are about fifteen to twenty feet tall and are colored white with orange and red lines. They are humanoid-shaped and possess enormous strength and durability. Small arms fire is useless against them, and only the powers and attacks of A Rank level heroes or higher could damage them. However, the Hero Killers had the advantage in tireless endurance and sheer force of numbers. Their sole purpose is to battle and collect combat data on their opponents. It is assumed that they were also used to test Unchain's abilities.

Their first and only appearance was during the Unchain Arc, when Rio was unexpectedly kidnapped by the conspirators. In order to draw attention away from the search for her, Teramishi unleashed the Hero Killers on the public, and blamed the whole affair on Jackal. At first the lower-ranking heroes were unable to stop them, and even the higher A-Rank heroes were having trouble dealing with them.

The Hero Killers would have eventually overwhelmed them were it not for the efforts of Crea , Mirea , Gengo , Kreios and Ratman. The main control computer was shut down, thereby deactivating all the Hero Killers, leaving the public to believe that the heroes had defeated them.