In the Brotherhood house, you will be trapped in a large room with zombies. Take out the zombies with your pistol and baseball bat, but save all the shotgun shells that you can. When you defeat them all, the Deer Haunter crashes through the wall. The key to defeating it is to walk in circles around the beast in the middle of the room, continually shooting it in the torso with your shotgun while taking minimal damage. When it is defeated, the door to the next room will open. Additionally, in the room where the Deer Haunter is found, use your baseball bat to kill all the zombies. Do not use your guns; save them. When the Deer Haunter comes out of the wall, run past him and into his cave. Put your back to the wall and shoot him. He will not be able to hit you.
When the Deer Haunter breaks out of the wall, quickly run into the small opening where he just broke out of and start shooting. The Deer Haunter will be directly in front of you swinging, but he cannot hit you while your in there.