The librarian of the unseen university is an orang-utan. This was not always the case. He was magically transformed by events chronicled in The Light Fantastic - but since then no member of the university staff can remember who he was before hand... In looks he has the red-haired-rubber-sack-filled-with-water look of a very well grown (300lb) male.

The librarian is obsessed by the books in the university's library. The library is housed in the university but due to the huge magical content of the room, space has been distorted (LSpace). The university actually contains every book ever written, as well as all those that will be written or even could be written. Students have been known to go on long treks (several weeks) into the library and often they don't come back. The actual wizards know better than to mess with the powerful magic deep in the library. The Librarian is the only one who has a good working knowledge of his subjects (the books) who often have to be chained to the shelves for the safety of all involved.

The librarian is often referred to as "that bloody great monkey". This only happens once by any one person because if you survive the assault from 300lb of pure muscle it will not be forgotten easily. The librarian frequents the infamous Mended Drum, a pub in one of the less than desirable parts of town. Here he enjoys drinking lots of ale, playing a mechanical game in which you have to fire stones at pretend aliens and listening to "music with rocks in".

If the librarian was to sum up his life so far, he would say "Oook" which tends to make up his entire vocabulary and can only be understood by very few individuals. The librarians mood can always be guessed by watching to see whether he is trying to kill anybody at the time.