The origin of Halloween Jack-o'-lanterns is that in the 5th century BC, the Celtics in Ireland thought that1October 3rd1day was the most haunted day of the year, so the diviners at that time used witchcraft to drive away the monsters that were said to wander around. Later, in the Middle Ages, people changed to dress in animal costumes and put on terrible masks to drive away monsters in the night on the eve of Halloween. Generally, Halloween decorations are mainly black and orange. It happened that the end of October was the harvest period of orange pumpkins, so pumpkins became one of the protagonists of Halloween.