Killer is a notorious pirate in the anime series One Piece, serving as the combatant of the Kid Pirates and a member of the Worst Generation, a group of powerful rookies. Known for his distinctive helmet and fearsome combat skills, Killer is fiercely loyal to his captain, Eustass Kid. Despite his often ruthless demeanor, he possesses a strong sense of honor. Killer's character development becomes more prominent during the Wano Country arc, where he faces significant challenges that test his loyalty and resolve. His journey highlights themes of friendship and resilience.