Cool cat,
I don't have a MainCoons, but I've got a huge long hair black cat
that is 12 years old as well now. He had to have an operation around
Christmas that cost me $2,500. He's pretty aggresive, a Dalmation came up to him and he attached himself to his face via his claws.
As the dog yelp and ran away my cat chased him for a few feet. He always brings his fresh kills to the front door
for us to see. He dragged a squirrel home once.