I've heard that another difference about the Oz book and the movie is when the four of them went to see the Wizard, they only got to see him one at a time. And when they each saw the Wizard, he took on a different form. When Dorothy saw him, he was a huge scary head like in the movie. When the Scarecrow saw him, he was a beautiful fairy girl. The Tin Man saw him as a huge growling beast, and the lion saw him as a big ball of fire. And when they defeated the witch and they all went to see him. He turned out to be invisible. But Toto managed to drag him out of his hiding place. And the Wizard ended up showing them how he operated those four monsters by machinery. I think it would be neat if the Muppet Wizard of Oz featured all that.