Mono is the main protagonist in the video game 'Little Nightmares II.' He is a young, mysterious boy who wears a paper bag over his head, concealing his identity. Throughout the game, Mono embarks on a perilous journey through a distorted world, teaming up with another character named Six. Mono’s role is central to the narrative, as he must overcome terrifying obstacles and unravel the dark secrets of the world, ultimately shaping the fate of himself and Six.