I've been playing around with the idea of creating a Bestiary -
A bestiary, or Bestiarum vocabulum is a compendium of beasts. Bestiaries were made popular in the Middle Ages in illustrated volumes that described various animals, birds and even rocks. The natural history and illustration of each beast was usually accompanied by a moral lesson. This reflected the belief that the world itself was the Word of God, and that every living thing had its own special meaning. For example, the pelican, which was believed to tear open its breast to bring its young to life with its own blood, was a living representation of Jesus. The bestiary, then, is also a reference to the symbolic language of animals in Western Christian art and literature.
Mine, on the other hand, would be an alphabet version with somewhat darker creatures in it, things that inhabit the nightmares of children. I'll have to test out a few on my little ones!