The bestiary, or "book of beasts", is more than just an expansion of the Physiologus, though the two have much in common. The bestiary also describes a beast and uses that description as a basis for an allegorical teaching, but by including text from other sources it goes further; and while still not a "zoology textbook", it is not only a religious text, but also a description of the world as it was known.

To learn more about bestiaries, visit The Medieval Bestiary Animals of the Middle Ages.