Most cat shows have a category for non-purebred house cats. Your's can steal the show with some tips Capital 9 TV (NY):
"When it comes to the household pet category, judges really have no guidelines for judging a household pet as they do a purebred. Every purebred has its standards and the cat is judged on those standards. But the household pet, it's basically a beauty and personality contest. So each judge can have a different opinion of what is beautiful. But to be a beautiful kitty, you need to be a clean kitty. If you purr a lot, that is good. Personality is extremely important because when they get in a show hall, it can be a different environment and they can become very frightened. So the cat needs to be at ease in a noisy environment," Washburn said.