''Beast Poetry'' refers to a popular form of Medieval Literature, which involved the personification (giving Human-like qualities such as emotions, etc) of Animals. This form of writing was used to express tradition and example. They were also used as ''cautionary tales'' to express (often) how ''Christian Virtue'' was needed to overcome Evil.
The style began around the 8th Century AD and peaked around the 12th Century AD. The previously discussed French character ''Reynard The Fox'' was a prime example of Beast Poetry. Another classic example – especially when conveying political dis-satisfaction, was Chaucer's ''Canterbury Tales''.
Every Country had a form of Beast Poetry and related literature. Although it began to fade in the 15th Century, it experienced a resurgence in the 19th Century – and is still a common form of device in animated cartoons and movies.