 The movie is based on the second and third Oz books: "The Land of  Oz" and "Ozma of Oz". Elements from the former include the  introduction of Jack Pumpkinhead, the witch Mombi and her powder of  life, the conquest of the Emerald City, the escape by flying sofa,  and the search for Princess Ozma. From the latter comes the return  of Dorothy, the talking chicken Billina, the wheelers, the discovery  of Tick