36 years old, scared of anyone, refuses to talk sometimes, schizophrenic (mentally ill), can't understand sometimes (It's debated if he had dyslexia), claims he can hear shouting when no-one is in the room, abused by Artyom but is protected and spoken to by Igor, barely walk but has functioning legs, doesn't believe he is human, because of what he was told he believes he's nothing but a guinea pig, extremely bad anxiety, tend to throw up blood if he feels really sick