Urbants-Creatures that move quickly around on their massive arms, and their "legs" dangle about from their torso, at about elbow length. They can move fairly quickly, but not as fast as an obese human, and can "jump" fairly high. Their "legs" are very powerful, and can kill with one blow. The bad thing is, Urbants cannot block attacks at their heads, which have relatively no neck, from the length of their legs being so short.
You find a book in the library, then when you start to read it, seems to change from pages of words to pages of images that seem to live and move. If you touch the page after the images appear, you travel into the story and now live in that world.
There is a book on that world, that leads back to this one.