 But in the 1930s, A.S. Fishbach, Ben Cooper, Inc., and other firms began mass-producing Halloween costumes for sale in stores as trick-or-treating became popular in North America.Halloween costumes are often designed to imitate supernatural and scary beings.Costumes are traditionally those of monsters such as vampires, werewolves, zombies, ghosts, skeletons, witches, goblins, trolls, devils, etc.