The librarian does not like goblins because they do not respect books, quiet, rules, or much of anything else. This is unfortunate as his library has several entrances via the labyrinth of the goblin kingdom.
The librarian is not fond of Jareth the goblin king, who does not respect much of anything else either. This is unfortunate because Jareth occasionally wanders into the library when he is bored, or wants information.
The librarian does not, in fact, like much of anyone else. Patrons are such a bother, always coming in and taking the books off the shelves and leafing through them as if they were just ink on paper, there for nothing more than being read. This is unfortunate, because he is the librarian.
In an attempt to protect the precious books, the entrances to the libraries are designed to appear and disappear very randomly around the kingdom, which really has as many drawbacks as it does advantages because people tend to wander in by mistake. Because this is a library, the librarian is aware he's not actually within his rights to chase patrons away unless he can cite a good reason, but you'd better be warned he's always on the lookout for one. The goblins frequently give him reasons to chase them out, limping after them and menacing with his heavy walking cane. Because he is old, and very large, and not especially fast, the goblins will sometimes bait him deliberately, but this is risky because he's not nearly as slow as he looks, and he is very far from dull-witted. While in the library you'd better behave, or you could find this out firsthand.