Halloween.

Halloween is an annual holiday celebrated on October 31. It's based on the Celtic festival (where people marked the end of the light and the beginning of the dark season). People usually do different activities for this holiday like  trick-or-treat, use costumes, make costume parties, cave jack-o'-lantern, tell ghost stories or just watch horror films at some house. Halloween have changed a lot through the years by the influence of the Celtics, the Catholics and the Romans, the mix of those traditions changed Halloween to make the one that we celebrate these days.