Tolkien's world certainly contains many creatures that may be called 'unreal', but there are zounds more of these to be found in the mythologies of different cultures. What of the griffin, the unicorn, the centaur, the pegasus, the sprite and loads more? Do we get any insight into the professor's thought process regarding this? Did he even give especial thought to which of these fantasy creatures would grace his stories and which not? Perhaps many of these, like the griffin, boast too extravagant and flamboyant characteristics and features, and are not very fitting for Tolkien's creation, where most things and concepts seem subtle and wonderfully worked out. On the other hand, a creature like the unicorn does not seem over-done at all, and is graceful enough for us to be able to imagine it as part of Middle-earth. Basically, it is just a horse with a horn, much like an elf is just a human with funky ears. Thoughts and opinions?