Killer is a tall, muscular man with wild blonde hair reaching his thighs, hidden beneath a striped helmet with headphones. He wears a polka-dot shirt and blue riding chaps, carrying detachable scythes. Like the rest of the Kid Pirates, he's arrogant yet level-headed, more calm than his captain. He remains silent during combat, focusing on eliminating enemies, and possesses a knowledge of history that often aids his crew. After the timeskip, he's shown advising his captain to be polite, preventing unnecessary fights.