i think id go with a 12ga......first 2 shots will be slugs...the last 3 will be 00 buck...the first 2 youll have time to think and react maybe.....the last 3 he will be up on your....butt.....and you will just want to spray lead.....00 will hit hard and have enough pellets to possibly hit something the animal needs......or maybe id go with my browning buckmark pistol in 22lr......i can dump a 10rd mag straight in the head of the bear or cat or wahtever is after me.....i dont think its going to keep coming......