Muzan Kibutsuji is a tall Japanese young man (5'7") with a strong muscular body and unnaturally pale skin. He's 17 years old. His cat-like crimson red eyes glows. He has sharp, blue nails on his hands. He's a demon with short black curly hair and sharp teeth. Muzan is cold-hearted, ruthless, intimidating, charming, manipulative, controlling and intelligent. Rarely he can be sad or happy. His body can transform into incredible and terrible forms, like double mouth on his stomach. He eats people.