Evil Genius

Wikipedia wrote:The term "Halloween" is derived from Hallowe'en, an old contraction, still retained in Scotland, Ireland and some parts of Canada, of "All Hallow's Eve," so called as it is the evening (or eve) before the feast of All Saints (an important day in the Christian calendar), which used to be called "All Hallows" derived from All Hallowed Souls. In Ireland, the name was Hallow Eve and this name is still used by some older people. Halloween was formerly also sometimes called All Saints' Eve. The holiday was a day of religious festivities in various northern European pagan traditions, until it was appropriated by Christian missionaries and given a Christian reinterpretation. In Mexico, All Saint's Day, following Halloween, is the Day of the Dead.

Halloween is also called Pooky Night in some parts of Ireland, presumably named after the púca, a mischievous spirit.

In Britain and Ireland in particular, the pagan Celts celebrated the Day of the Dead on All Hallows Day (1st November). The spirits supposedly rose from the dead and, in order to attract them, food was left on the doors. To scare off the evil spirits, the Celts wore masks. When the Romans invaded Britain, they embellished the tradition with their own, which is both a celebration of the harvest and of honoring the dead. Very much later, these traditions were transported to the United States and Canada and other places in the New World.

Halloween is sometimes associated with the occult. Many European cultural traditions hold that Halloween is one of the "liminal" times of the year when the spirit world can make contact with the natural world and when magic is most potent (see, for example, Catalan mythology about witches).