That is really cool!! I spent WAY TOO LONG trying to figure out how a cat has 18 toes.
I had a polydactyl once. She had 20 toes I believe, but her front paws looked like mittens. She had "thumbs" instead of just having the claw on the paw. That sounds funny. I know what I mean! Her back feet just had 5 toes all together. You could barely notice the back ones but the front were so cute!!
There might be a pic in the tortie thread that you can see her mittens in.