Supernatural (2005)

S1E5 Bloody Mary

In a quiet Nebraska suburb, a group of high school friends engages in a playful dare, urging their buddy Charlie to chant "Bloody Mary, Bloody Mary, Bloody Mary" in front of a mirror. Unbeknownst to them, this act triggers a wave of chilling murders. Sam and Dean discover that the vengeful spirit can move through any reflective surface when seeking her prey. Alarmed by the teens' unintentional summoning of Bloody Mary, the brothers hasten to confront the malevolent entity before she claims more lives.