Medieval European work in verse or prose, often illustrated, consisting of a collection of stories, each based on a description of certain qualities of the subject, usually an animal or a plant.
The stories were allegories, used for moral and religious instruction and admonition. They ultimately were derived from the Greek Physiologus , a text compiled by an unknown author before the mid 2nd century AD. Many traditional attributes of real or mythical creatures derive from bestiaries, such as the phoenix's burning itself to be born again and the parental love of the pelican, which, believed to feed its young by gashing its own breast, became a symbol of Christ.