Kuchisake-Onna is a japanese ghost that was attacked by her husband who cut her mouth deeply, leaving her with scars. If you answer her question with "Yes", she will take off her mask, revealing her scars and ask again, killing you regardless of your answer. If you say "No", then she will kill you instantly. If you respond "So-so", or "You're ok", then it'll leave her stunned and confused, giving you a chance to escape.