"Come here, enough hiding! I know you're there. I'll find you...soon." - A Blind One searching for Artyom.
Librarians look similar to ordinary gorillas in both posture and overall appearance. Their arms are longer and skinnier, however and they are slightly taller. The hands have two long fingers and a thumb while their feet have two equally long normal toes and a much shorter back toe, or dewclaw and they have pointed ears. The upper lip of a librarian hangs low enough to cover the creature's shark-like teeth. The most common kind of librarians are covered in grey-blue skin and are found all over the library, preferring the top floor. They are curious and will agressively charge a supposed threat, though they will back down if the target doesn't run, turn their back on the librarian or shoots anywhere near it. They can be stared down but a shot will send them into an aggressive state that won't end until the trespasser or the librarian in question are killed. In the archives underneath the library are a breed of librarians known as Black Librarians. These creature have thick, black fur covering all their body and a missing upper lip, revealing rows of sharp teeth. The head of this breed is also deformed and covered in tumorous bulges.
They are some of the most powerful, intelligent, and frightening enemies Artyom will have to face. They can memorize small pieces of literature, place traps, and are even capable of semi-communication in the form of creating a temporary neural-link by staring a human in the eye. Librarians can apparently utter short sentences about overdue books and in the novel, a librarian that had just killed Daniel mimics Artyom's speech, and presumably said "Go away!". It is implied that the librarian said this on purpose, but may have just been mimicry. Another notable, intelligent action performed by a Librarian was placing ammo near a hole in the wall as a trap. If Artyom attempted to grab the ammo, it would grab Artyom through the wall and attempt to kill him.
The blind ones closely resemble pre-war gorillas, save for a few details - their complete lack of eyes and their almost completely deteriorated fur. They primarily rely on sound and smell to locate their prey. They are extremely strong and durable, and are able to kill any human; or any similar sized creature; in seconds. They are the only surface mutants found in Novosibirsk, presumably because they are the only ones able to withstand the radiation levels. The blind ones have also developed an ability to telepathically communicate with each other. They are also able to do so with humans, since Artyom is able to understand them. When faced with a blind one, running is the last thing Artyom should do, since they will immediately know his location and give chase. Likewise, engaging one in combat is ill-advised, since it will take excessive gunfire to bring one down. The best option is to sneak around it. Keep in mind that a blind one will be able to sense Artyom if he is nearby, even if he is crouching, and will start following him, though it will not attack until he is close.