An ordinary zombie is slow, stupid and dangerous only for an unarmed and confused person who is in a confined space. These zombies are called “sleepers.” He who has eaten any meat becomes smarter, faster and presents a problem even for those who own weapons of the living. They're called the "Wake Up Zombies." But the worst of them are those who were able to get to the living, unconverted meat of the individual of their species .. They change even outwardly, acquiring new opportunities, their intelligence increases, but all this: power, speed, cunning - is used only to kill the living. The samples obtained after morphing - they are called "necromorphs" - are extremely dangerous and can be neutralized only by special groups authorized by the management for such work. The textbook "Basics of life safety" (section "Zombology", chapter 1) "But survivors who have lost a human in themselves are more terrible than any morph. Remember that, children.". Note by a one-armed teacher on OBJ.