An extra-toes cat isn't a breed. It's any cat born with polydactyly, a harmless genetic variation that adds toes to one or more paws. Most have six or seven on a front paw, and some have a thumb-like toe that gives them a mitten look. The trait is dominant, so it shows up in all kinds of coats and sizes. The Hemingway nickname comes from the writer Ernest Hemingway, whose Key West home still houses descendants of his six-toed cat.
Most polydactyls are domestic shorthairs or longhairs, so personality, energy and grooming needs vary as much as they do in any cat. Expect a medium-sized cat of roughly 6 to 15 pounds who lives 12 to 18 years, with moderate shedding. The main care difference is claws. Extra nails may not wear down on their own and can curl into the paw pads, so regular checks and trims matter.