Many Halloween traditions we do today go back to Celtic times.
In pre-Christian times, many people believed that spirits from the underworld and ghosts of dead people could visit the world of the living on the night of October 31. These spirits could harm the living or take them back to the underworld.
To avoid this, people started dressing up as ghosts and spirits if they left their homes, with the hope that this would confuse the ghosts and spirits. This may be the origin of the Halloween costumes worn today.
The fear of crossing paths with black cats, afraid that they might bring bad luck, has its roots in the Middle Ages, when many people believed that witches avoided detection by turning themselves into cats. The superstition about walking under ladders may have come from the ancient Egyptians, who believed that triangles were sacred.
The jack-o’lantern originated from an Irish myth in which Stingy Jack invited the devil to have a drink with him, tricked the devil to turn into a coin to pay for the drinks and put a silver cross, which prevents the devil from turning back to himself, with the coin in his pocket. Jack eventually freed the devil, after he promised not to bother Jack for one year and that if Jack died, he would not claim his soul.
The next year, Jack tricked the devil into climbing a tree to pick fruit, carved a sign of the cross into the tree so that the devil could not come down until he promised not to bother Jack for 10 more years.
Soon after, Jack died. God would not allow him into heaven.
The devil, upset by Jack’s tricks and keeping his word not to claim his soul, wouldn’t allow Jack into hell.
So he sent Jack off into the night with only a burning coal to light his way. Jack put the coal into a carved-out turnip and roamed the Earth with it. The Irish referred to this ghostly figure as “Jack of the Lantern,” and then, simply “Jack O’Lantern.”
And zombies? Folklore experts traced the zombie idea back to Haitian Vodou practices, to tales of people brought back from the dead as shambling shadows of themselves. In the late 20th century and early into the 21st, zombies became the rotted flesh version created to be slaves, and biting everybody, turning them into zombies too.