Bloody Mary is a folklore legend consisting of a ghost, phantom, or spirit conjured to reveal the future. She is said to appear in a mirror when her name is chanted repeatedly (usually three times). The Bloody Mary apparition may be benign or malevolent, depending on historic variations of the legend. Bloody Mary appearances are mostly "witnessed" in group participation play.

Some say she was a widow who killed her children, while some say she was a young child who was murdered and is wandering around her grave. Other tales say the ghost is Mary Worth, a woman said to be a witch who was burned at the stake.

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