Bloody Mary is a Western divination-and-summoning game in which a person, facing a mirror in a dark room, chants the name "Bloody Mary" a set number of times until an apparition appears in the glass. The summoned being is said to harm the one who calls it.
Because the very act of speaking the name is the ritual that draws the figure out from beyond the mirror, it embodies most directly our sealing thesis, in which to name is to summon.