The Giant Horse of Oz (1928) is the twenty-second of the Oz books created by L. Frank Baum and the eighth written by Ruth Plumly Thompson. It was Illustrated by John R. Neill.
Deep in the blue Munchkin Country, in the Lost Lake of Orizon, you will find the five Ozure Islands. Twenty-five years ago - before Dorothy's farmhouse landed on the Wicked Witch of the East [and if you don't know that story, you must read The Wonderful Wizard of Oz (1900)], the royal family of the Munchkins, including King Cheeriobed and Prince Philador, were imprisoned on the Ozure Islands by the old witch Mombi [who was first introduced in The Marvelous Land of Oz (1904) and then mixed up more mischief in The Lost King of Oz (1925)]. After abducting the lovely Queen Orin from the Ozure Islands, Mombi placed a fire breathing, smoke snorting, horrible water monster called Quiberon in the lake to guard the rest of her prisoners.