Evil librarians in fiction come in a variety of forms. They can be cult members, who believe either that the world is not ready for any advanced knowledge or are an organization that controls the flow of knowledge. They might even be literal monsters. In these cases, libraries are often perilous.
Often times, works featuring the non-sexy variety of evil librarians will be favorites of actual librarians.
- Bloom County. In one strip, Binkley has a visitor from his Closet of Anxieties: the librarian Mrs. McGreevy. While still inside the closet, she flings an axe that passes over his head and hits the wall behind him. When she steps out of the closet she's holding another axe. She's there about a library book he forgot to return.
Mrs. McGreevy: 119 weeks overdue, dear...
- Calvin and Hobbes. Calvin at least believes this trope to be true, although his Mom does try to bring him back to reality:
Calvin: Omigosh! This library book was due two days ago! What will they do? Are they going to interrogate me and beat me up?! Are they going to break my knees?? Will I have to sign some confession???
Calvin's Mom: They'll fine you ten cents. Now go return it.
Calvin: The way some of those librarians look at you, I naturally assumed the consequences would be more dire.
- The beginning of Ghostbusters has the team facing off against a ghostly librarian.
- Alcatraz Vs. The Evil Librarians runs on this trope. The titular evil librarians control a large part of the world, with the exception of the Freelands. There are several different branches, including the Wardens of Standard, the Scrivener's Bones, the Shattering Glass, and Dark Oculators. The Librarians of Alexandria are not part of the organization, but that doesn't make them any less dangerous.
- There is a short story in an anthology about a boy who suspects his town librarian is evil, particularly given how nasty she is towards those who accidentally damage her books. It doesn't help that such people tend to disappear after catching her ire. He and a friend stay in the library after closing and discover the Librarian is in fact Morgan LeFay, and that she's actually been turning people she doesn't like into books to add to her collection. LeFay plans the same fate for the protagonist, threatening to make him a boring reference book no one will want to check out, only to accidentally unlock one of her previous victims: Merlin. Needless to say, the library gets a new, much more likeable caretaker the next day.
- The villain from The Library Policeman in Four Past Midnight is an Ambiguously Human creature posing as a librarian.
- The Librarian from Wings of Fire is a villain who tries to kill the protagonists except only because she is being permanently mind-controlled by the Big Bad. She turns out to be willing to help the protagonists when she is temporarily freed.
- In Parks and Recreation, Ron's second ex-wife Tammy II works at the Pawnee Library. She is one of the show's recurring antagonists, regularly going out of her way to seduce and lead Ron away, or trying to mess up his attempts at finding happiness. She also happily uses her position to blackmail and embarrass people. Because of her, the entire Parks department, especially Leslie, has a disdain for libraries.
- Al Bundy of Married... with Children had to confront one from his childhood when he needed to return an overdue library book he'd once borrowed. While Al himself is no prize, the woman fully admits to having always hated him and to have specifically held off retirement simply to nail him over the book.
- Despite being a bibliophile himself, Brick of The Middle views his school librarian as such. Interestingly, it did not start out as adversarial. The librarian admits when Brick first started coming, she was very happy to see such an enthusiastic reader. But Brick's irresponsibility and inability to return the books he borrows inevitably lead to her actually trying to hold him back from graduating to the next grade.
- I. M. Meen: The titular antagonist owns a library, where kids go to study despite him hating them. Meen possesses a magic book that sucks the children into his own labyrinth, full of monsters and other dangers.
- The Grey Lady, first introduced in Ghostbusters, stars as an antagonist in Ghostbusters: The Video Game.
- Psychonauts 2: The Librarian archetype inside Cassie O'Pia's mind is holding her hostage, preventing her from going outside Green Needle Gulch or seeing her friends so Cassie can Never Be Hurt Again. When Raz enters her mind, Librarian Cassie wants him to round up Cassie's archetypes so that she can be the dominant archetype in her head. When Raz rounds up all the other archetypes together, Librarian Cassie gets mad and turns into the Die-Brarian to try and kill Raz. In the end, the "evil" part ends up being subverted with the fact that Librarian Cassie's a Well-Intentioned Extremist but the way that she's coping after the battle with Maligula is ultimately unhealthy. She reforms after the boss battle after the other archetypes tell her that they're all equally important parts of Cassie O'Pia and that they need to all be together in order to move on.
- In Nightmare Ned, a librarian tries to crush the titular character in a book. If Ned attacks her with his yo-yo, she turns into a worm and then burrows into the book.