The Librarian of Unseen University is an orang-utan. This was not always the case. He was magically transformed by the events chronicled in The Light Fantastic - but since then no member of the University staff can remeber who he was beforehand. In addition, a page was torn out of the relevant year book; no one knows why, or why the place was marked with a banana skin. There is a rumour that the Librarian was once Dr Horace Worblehat, B. Thau, D.M., but no one utters this out loud. Dr Worblehat is dimly remembered as being quiet, polite and generally the kind of person you cannot remember in the school photo.

It is clear that whatever he once was the Librarian is now blissfully happy in himself, reckoning that the prehensile toes and extra-long arms are very helpful in his role. In a sense, say the wizards, it is as though he always was the Librarian and whatever inoffensive human shape he had for the first several decades of his life, he was merely marking time until he could become his own self.

In looks he has the red-haired-rubber-sack-filled-with-water look of a very well grown (300lb) male, although he has not developed the overlarge cheek pads that are a feature of a dominant male orang. This is because he is not, strictly, a dominant male - he is an ex-officio member of the college council and a member of the faculty and therefore quite rightly regards the Archchancellor as the dominant male, even though the Archchancellor does not often sit high up in trees with a large leaf on his head.

Habits and habitat: he has a book-lined nest in a cubby hole under the desk in the middle of the Library. He hides there under his tattered blanket when he is worried. He appears to want nothing more than soft fruit, a regular supply of index cards and the opportunity, every month or so, to hop over the wall of the Patrician's private menagerie. (This is a puzzle. There are no orangs in the menagerie. Nor are there any other kinds of ape.) He is generally naked but he does wear an old green robe when he's had a bath or modesty really requires it.

The Librarian is, of course, very much in favor of reading in general, but readers in particular get on his nerves. There is something sacrilegious about the way people keep taking books off the shelves and wearing out the words by reading them. He likes people who love and respect books, and the best way to do that, in the Librarian's opinion, is to leave them on the shelves where Nature intended them to be.