Bloody Mary

Mary I of England (1516–1558), Queen of England and Ireland, so called because of her execution of numerous protestants.
There is an urban legend that was made about her haunting mirrors ever since she was found dead near a broken mirror with her face smashed in beyond recognition.

Martin: “...And so she haunts every mirror and can only be summoned by saying her name 3 times!”
Luke: “I’m NOT gonna say that 3 times, I’m not stupid.”
Martin: “Come on, it’s just a scary children’s story. What could go wrong?”
Luke: “Fine... Bloody Mary, Bloody Mary... f*** this I’m out!”