Polydactyl

Polydactyl: Multi-Toed. There are many Maine Coon cats that have 6 toes! They originated along with regular Maine Coons around 300 years ago. Boston Harbor has been scientifically designated the arrival point in this country of the polydactyl cat, and location of the first polydactyl in America. It was an easy matter for the cute poly cats to be accepted aboard the Maine-bound vessels, for luck as well as something new to share with family at home. The Boston wharf side poly cats and Maine-bound schooner cats mingled as they pleased. http://maine-cooncat.com/poly_mc.html

This is a video on you tube showing polydactyl cats.

They look like they have two paws!