The first time you see an abomination you might be terrified.. this is understandable. If you are in T2 troll armor they will likely 2 shot you if you are not blocking properly. They are very slow and their moves are easy to telegraph. I personally would recommend just avoiding them at first. Their pathing is TERRIBLE.. you can lose them through trees easily.

If you want to kill them and can get on top of a crypt they can't hit you and you can widdle them down with your ax.. fire arrows work ok but they are resistant to pierce so it will take you like 30 arrows to bring one down.

Bottom line.. if they are too much then just avoid them. Unlike a lot of other mobs they actually will not chase you far they give up rather easily.