The Silver Princess in Oz

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. When they reach Jinnicky's palace, they find that Jinnicky has been deposed and enchanted by an untrustworthy slave.