Ragdoll Death physics

I have an idea about minecraft with ragdoll physics. not on all mobs but some like: Villagers and their variants, skeleton and variants, zombies and their variants and (animals and their variants, optional). but not all ok, and there could be a choice in world creation, so if the player wants his world to have ragdoll physics he will enable the option just like the option for bonus chests or cheats, but if does not want to have ragdoll physics then he will just create the world and it will be just a normal classic world. and also you would think that it will create lag and everything, no the mobs which are only killed by the player will have physics and the ones which died under the sun or somewhere else where the player have not touched them they will not have physics. Also the player can also make the ragdoll despawn by burning it, this will prevent it from lag. Also player could drag the ragdoll with lead and play around. This will make minecraft much more fun to play and not to leave it. Hope you will read it. Thank You.