a mob which acts as a turret

I'd like to see a mob witch act like a turret but this mob can maybe use a crossbow or a bow (like skeletons), The reason why this mob is for getting help to protect a village from mobs, or help the player during raids or only for protect the player base.I know there is the snowgolem already but is ususless and the fire charge he shoot do only fire damage, so is pretty ususless. Maybe the player can give to this new mob his bow/crossbow to make this mob more stronger and give him arrows or other bows or crossbows in case they break their weapon. 

I'm sorry for my bad english but i hope is all understable.