Medical term originating in Greek “Poly” pertains to many and “Dactyl” pertaining to the toes/fingers.
Polydactyl cats have more than normal amount of toes usually on the front feet but they can also be on the back feet. Normal cats have 18 toes polydactyls usually have up to 28 toes.
It is funny you always hear about the “Crazy Cat Lady", but did you know Ernest Hemingway a famous writer was a “Crazy Cat Guy”? It all started after he was given a white polydactyl cat by a ship captain her name was Snowball. At his home off Key West, FL he collected over 50 cats and almost half were Polydactyl. Thanks to crazy evolution and Hemingway’s obsession, they are often referred to as “Hemingway cats”. They were also considered good luck at sea and they also earned their keep as excellent mouse hunters and they had good balance when they hit the rough waters.
A few interesting facts from catsters.com
Being polydactyl is not a disease or medical condition but they do need special care to make sure the “extra” nails do not grow into the pads. Regular nail trims once every few weeks should be ok.