Muzan Kibutsuji is a tall and muscular man who appears to be in his 20's, with an unnaturally pale skin complexion that can be easily confused as being unhealthy and sickly. He stands 179 cm tall, and has curly black hair, and sharp, almond-shaped red eyes, his pupils are slit shaped. He also has sharp, blue nails on each hand that he can change to look like normal human fingernails. He generally looks cold and emotionless, but has a soft smile that makes his eyes narrow, almost menacingly.