The Royal Book of Oz (1921) is the fifteenth in the series of Oz books, and the first to be written after L. Frank Baum's death. The Scarecrow is upset when Professor Woggle-bug tells him that he has no family, so he goes back to the corn-field where Dorothy Gale found him to trace his "roots." When he fails to return, Dorothy and the Cowardly Lion set out to search for him. They meet an elderly knight, Sir Hokus of Pokes. They also meet the Doubtful Dromedary and the Comfortable Camel. Together, they have several curious adventures while searching for the Scarecrow.
Lyman Frank Baum (May 15, 1856 – May 6, 1919) was an American author known for his children's books, particularly The Wonderful Wizard of Oz and its sequels. He wrote 14 novels in the Oz series, plus 41 other novels (not including four lost, unpublished novels), 83 short stories, over 200 poems, and at least 42 scripts. He made numerous attempts to bring his works to the stage and screen; the 1939 adaptation of the first Oz book became a landmark of 20th-century cinema. Ruth Plumly Thompson (27 July 1891 – 6 April 1976) was an American writer of children's stories, best known for writing many novels placed in Oz, the fictional land of L. Frank Baum's classic children's novel The Wonderful Wizard of Oz and its sequels.