Tuxedo describes a coat pattern, not a breed. These cats are bicolor, usually black and white, with a white chest that looks like a shirtfront and often white paws, chin or a facial blaze. Grey-and-white tuxedos exist too. The pattern comes from white spotting variation in the KIT gene, and because it isn't sex-linked, males and females are about equally common.
Most tuxedos are domestic shorthairs, though the pattern also shows up in breeds such as the Maine Coon and Persian, which can mean longer coats and more brushing. Tuxedos typically weigh 6 to 14 pounds and live 12 to 18 years, so adopting one is a long commitment. Stories about tuxedo personalities are fun but unproven. The cat's age, energy and coat tell you more than its markings.