Tuxedo describes a coat pattern, not a breed: a bicolor cat, usually black and white, with a white chest that looks like a shirtfront and often white paws, chin or a facial blaze. Gray-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 appears in breeds such as the Maine Coon and British Shorthair. Color doesn't set personality, so adopters will meet every temperament and energy level. Expect a medium-size cat of roughly 6 to 14 pounds with moderate shedding, often living 12 to 18 years, which makes adoption a long commitment worth planning for.