Halloween costumes are traditionally modeled after monsters such as ghosts,skeletons,witches,and devils.Over time,the costume selection extended to include popular characters from fiction,celebrities,and generic archetypes such as ninjas and princesses.
Dressing up in costumes and going "guising" was prevalent in Scotland and Ireland at Halloween by the 19th century.Costuming became popular for Halloween parties in the US in the early 20th century,as often for adults as for children.The first mass-produced Halloween costumes appeared in stores in the 1930s when trick-or-treating was becoming popular in the United States.