- A new species of mutants about which nothing definitive is known. The prominent theory is that a Karlik is the result of a human's genes that underwent severe degeneration because of unidentified toxins. Despite being considerably short, the strength of a Karlik can rival that of a young Bloodsucker.
In S.T.A.L.K.E.R. books karlik and the Controller are in some kind of connection.They have the ability of using psy attacks, and they can feel the prey from kilometers. If you kill one of them , you must destroy ( burn, etc.) the body,or a controller will "grow out" from the ground , where the corpse lies. A stalker myth says that they are hunting in pairs. They live in caves , or in dark holes.
- The item Karlik's ear can rarely be found to loot on the corpse.
- Faster than a Zombie when moving, they run round after the player and eventually employ the zombie's "punch" attack.
- Will limp after they have been shot a couple of times, making them slower and easier to deal with.