Gauntlet's Bestiary of the Fourth Universe was a book in the TARDIS library. It had entries on all manner of beast in the fourth universe, including Bligh strawberries, Bliny scuttledabs, blister beetles, Blithewings and Blitzen fish. Each entry included an image of the creature, and information about them.
Susan Campbell and Lucie Miller sought this book in the TARDIS library for more information on Blitzen fish. They learned more about them, as one was wreaking havoc in the TARDIS. (AUDIO: Relative Dimensions)