I'm thinking 12 gauge, but I can understand that you don't often walk around in RI with a 12 gauge in hand.
It looks like that critter could give Cujo a run for his money!!
Yikes!
As Frithguild stated earlier, a fisher is just a smaller version of the wolverine with the same personality. When one of cable networks (Animal Planet, Discovery, NatGeo) had the show on mock animal battles, I was hoping they would match a 50-pound wolverine against a 70-pound pit bull in one of their simulations. It would have been a battle to the death for sure, I suspect the pit bull's death.