Bug or feature, but you can pack 1 corpse in a backpack, and carry the second in your hand. The corpse can also be transferred from hand to inventory. For each inventory, whether it is a backpack or a player, you can add 1 corpse. To remove the corpse from the hands and put it in the inventory(So you can carry something else in your hands when the corpse is in the inventory), you need to transfer the corpse to a backpack and unpack.