Ruth Plumly Thompson 
Silver Princess in Oz [EPUB ebook] 

The Silver Princess in Oz (1938) is the thirty-second of the Oz books created by L. Frank Baum and his successors, and the eighteenth written by Ruth Plumly Thompson. It was illustrated by John R. Neill. In this story, young King Randy of Regalia (from Thompson’s The Purple Prince of Oz) is visited by his old friend, Kabumpo, the Elegant Elephant of Pumperdink. Together, they set out to visit their friend Jinnicky the Red Jinn (also from Purple Prince) in the Land of Ev. On the way, they meet Planetty, the silver Princess from Anuther Planet, and her fire-breathing colt, Thun.