Before Shrek made it big on the silver screen, there was William Steig's SHREK!, a book about an ordinary ogre who leaves his swampy childhood home to go out and see the world.
Shrek, a horrid little ogre, goes out into the world to find adventure and along the way encounters a witch, a knight in armor, a dragon, and, finally, a hideous princess, who's even uglier than he is!