Political? Superhero-themed? Esoterically awesomely creative?? What dog costume will win the 20th Annual Jamaica Plain Costume Parade this Saturday?. Sponsored by JP Centre/South Main Streets, the costume parade and fashion show will feature a red carpet contest, prizes, music, and special guests. Special guests?? Scooby-Doo? Scrappy-Doo? The Paw Patrol? Mayor Humdinger?? Only time will tell.