Another known symbol being around for thousands of years is the Ghost. The ancient people believed that the recently dead would come to earth during this time of the year and mingle with the living any way they like.
So seeing a ghost of someone was very common in those times, but as time passed, now people have modernized the concept as you would see many people dressing up as ghosts. It is not only used for costumes, but many ghost props are used to decorate houses. Putting a ghost prop in your backyard surely will scare a lot of people.