John Dough was a common name for a gingerbread man at the turn of the 20th century, though the best-remembered John Dough is the character created by L. Frank Baum in his 1906 novel, "John Dough and the Cherub"; the character also makes a cameo appearance in Baum's "The Road to Oz".
 If the fragment known as "An Oz Book" is genuine, Baum may have intended to include John Dough in his fifteenth Oz book had he lived to write it.
Roger Stanton Baum (born 1938) is a former banker and stockbroker, and currently (as of 2005) a children's author, residing in Las Vegas.
 Baum publishes under the name Roger S. Baum.
 Baum is a former resident of Los Angeles.
 He also tours the country, reading from and signing his children's books.
 Baum is a great-grandson of L. Frank Baum, the original creator of the "Oz" series, and grandson of Frank Joslyn Baum, who published "The Laughing Dragon of Oz" in 1935.
 Many of Roger S. Baum's children's books are set in the same world.
The Wishing Horse of Oz (1935) is the twenty-ninth in the series of Oz books created by L. Frank Baum and his successors, and the fifteenth written by Ruth Plumly Thompson.
 It was Illustrated by John R. Neill.
 This book marked the point at which Thompson had written more Oz books than Baum himself.
The Wizard of Oz (1933) is a Canadian animated short film directed by Ted Eshbaugh.
 The story is credited to "Col. Frank Baum."
 Frank Joslyn Baum, a Lieutenant Colonel in the United States Army and eldest son of writer L. Frank Baum, was involved in the film's production, and may have had an involvement in the film's script, which is loosely inspired by the elder Baum's novel, "The Wonderful Wizard of Oz".
 It runs approximately eight and a half minutes and is nearly absent of language, working mainly with arrangements of classical music created by Carl W. Stalling.
Father Goose: His Book is a collection of nonsense poetry for children, written by L. Frank Baum and illustrated by W. W. Denslow, and first published in 1899.
 Though generally neglected a century later, the book was a groundbreaking sensation in its own era; "once America's best-selling children's book and L. Frank Baum's first success," "Father Goose" laid a foundation for the writing career that soon led to "The Wonderful Wizard of Oz" and all of Baum's later work.
The Red Jinn, later known as Jinnicky, is one of Ruth Plumly Thompson's most frequently occurring characters in her Oz books.
 He was first introduced in "Jack Pumpkinhead of Oz" as a mysterious figure who educates Jack Pumpkinhead on the use of the Pirate Sack.
 Although a detailed description is included in the text, "Jack Pumpkinhead of Oz" includes no illustrations of the Red Jinn aside from a gruesome color plate that did not appear outside the first edition, in which he has massive piercings.
 He was reintroduced, drawn, and given the name Jinnicky in "The Purple Prince of Oz"; he also appeared in the follow-up, "The Silver Princess in Oz".
 (He makes a cameo appearance in "The Wishing Horse of Oz", and he is the principal pre-existing character in Thompson's sub-canonical penultimate Oz book, "Yankee in Oz").
 Jack Snow apparently thought the Red Jinn was a separate character, for he considered "The Purple Prince of Oz" Jinnicky's first appearance in "Who's Who in Oz", though he did not include a separate Red Jinn entry.
The Dreamer of Oz: The L. Frank Baum Story is a 1990 made-for-television biographical film starring John Ritter as Lyman Frank Baum, the man who wrote "The Wonderful Wizard of Oz" and thirteen of the other Oz books.
 Also starring in this TV movie was Annette O'Toole as Baum's supportive wife, Maud, and Rue McClanahan as Baum's tough mother-in-law, Matilda Gage.
 John's son, Jason Ritter, makes his debut in this telefilm as Harry Neal Baum.
 At the time of the film's debut, O'Toole and Ritter also starred in "It", a TV miniseries where they played a couple.
The plays of L. Frank Baum are an important aspect of Baum's writing career about which some of the least is known.
 While even most brief biographies, long before the Internet, have noted Baum's work as a playwright, these works have been rarely performed beyond his lifetime, and almost none have been published aside from two scenarios and a first act of three unfinished works in "The Musical Fantasies of L. Frank Baum", compiled with an introduction by Alla T. Ford.
 Aside from his youthful success with "The Maid of Arran", his blockbuster eight-year run with "The Wizard of Oz", his failure with "The Woggle-Bug", and "The Tik-Tok Man of Oz" as source material for his novel, "Tik-Tok of Oz", very little is known about his dramatic output, and mostly from the publications of Michael Patrick Hearn, Susan Ferrara, and Katharine M. Rogers.
 Hearn identifies 41 different titles in the bibliography of the 2000 edition of "The Annotated Wizard of Oz", plus one play without a title, although some of these titles clearly refer to drafts of the same play, such as the early titles of "The Tik-Tok Man of Oz".
The Royal Book of Oz (1921) is the fifteenth in the series of Oz books, and the first by Ruth Plumly Thompson, to be written after L. Frank Baum's death.
 Although Baum was credited as the author, it was written entirely by Thompson.
 Beginning in the 1980s, some editions have correctly credited Thompson, although the cover of the 2001 edition by Dover Publications credits only Baum.
 The original introduction claimed that the book was based on notes by Baum, but this has been disproved.
 Baum's surviving notes, known as "An Oz Book" are known from four typewritten pages found at his publisher's, but their authenticity as Baum's work has been disputed.
 Even if genuine, they bear no resemblance to Thompson's book.
L. Frank Baum's Juvenile Speaker: Readings and Recitations in Prose and Verse, Humorous and Otherwise is an anthology of literary works by L. Frank Baum, author of the Oz books.
 The book was first published in 1910, with illustrations by veteran Baum artists John R. Neill and Maginel Wright Enright; a subsequent 1912 edition was retitled Baum's Own Book for Children.
 The book constitutes a complex element in the Baum bibliography.

Question: Jinnicky the Red Jinn makes a cameo in which twenty-ninth book by L. Frank Baum and his successors?
Answer: The Wishing Horse of Oz