I used to have a big grey Maine Coon called Christo - he died 14 months ago and I still miss him..
Big breeds of cats are like big dogs - more prone to organ failure and he only made it to 14, but that is pretty standard for a Maine Coon.
Anyway, to answer your question - a Maine Coon has tufts on it's ears and that cat doesn't seem to, so probably not one.
RE: Gray Cat for #caturday