Reset Entity to initial pose

I'm creating a mod to render mobs for wikis. I am trying to get Entity's to render with their initial pose. I can do so by creating a new entity from the entity's NBT, but this does not work on players as the game crashes when trying to get their NBT. I can just create a new EntityOtherPlayerMP with the same GameProfile but this breaks NPC players in servers. Is there any way to cancel an entity's animation, at least for one frame so I can render it and then let it continue?