Question: The Nine Tiny Piglets first appear in the fourth book set in the Land of Oz, written by L. Frank Baum, and illustrated by who?
Context: The Oz books form a book series that begins with "The Wonderful Wizard of Oz" (1900) and relate the fictional history of the Land of Oz.  Oz was created by author L. Frank Baum, who went on to write fourteen full-length Oz books.  All of the Baum written books are in the public domain in the United States.  Even while he was alive, Baum was styled as "the Royal Historian of Oz" to emphasize the concept that Oz is an actual place.  The illusion created was that characters such as Dorothy and Princess Ozma related their adventures in Oz to Baum themselves, by means of wireless telegraph. The Scarecrow of Oz is the ninth book set in the Land of Oz written by L. Frank Baum.  Published on July 16, 1915, it was Baum's personal favorite of the Oz books and tells of Cap'n Bill and Trot journeying to Oz and, with the help of the Scarecrow, overthrowing the cruel King Krewl of Jinxland.  Cap'n Bill and Trot (Mayre Griffiths) had previously appeared in two other novels by Baum, "The Sea Fairies" and "Sky Island". Dorothy and the Wizard in Oz is the fourth book set in the Land of Oz written by L. Frank Baum and illustrated by John R. Neill.  It was published on June 18, 1908 and reunites Dorothy with the humbug Wizard from "The Wonderful Wizard of Oz" (1900).  This is one of only two of the original fourteen Oz books (the other being "The Emerald City of Oz" (1910), to be illustrated with watercolor paintings. Glinda of Oz is the fourteenth Land of Oz book written by children's author L. Frank Baum, published on July 10, 1920.  It is the last book of the original Oz series, which was later continued by other authors.  Like most of the Oz books, the plot features a journey through some of the remoter regions of Oz; though in this case the pattern is doubled: Dorothy and Ozma travel to stop a war between the Flatheads and Skeezers; then Glinda and a cohort of Dorothy's friends set out to rescue them.  The book was dedicated to Baum's second son, Robert Stanton Baum. The Nine Tiny Piglets are characters in the Oz series.  They first appear in "Dorothy and the Wizard in Oz", owned by the Wizard of Oz and used for a trick in which he uses sleight of hand to make it appear as if he is pulling apart the piglets to make them appear, and pushing them together again to make them disappear.  He uses this trick to deceive the Mangaboos. The Munchkins are the natives of the fictional Munchkin Country in the Oz books by American author L. Frank Baum.  They first appear in the classic children's novel "The Wonderful Wizard of Oz" (1900).  They are described as only wearing shades of blue clothing, as blue is the Munchkins' favorite color, and the predominating color that officially represents the eastern quadrant in the Land of Oz.  They and the non-Munchkin Good Witch of the North who accompanies them upon Dorothy Gale's first arrival in Oz, are described as being the same height as Dorothy, who is hinted to be no older than twelve years old. 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. Cap'n Bill Weedles is a fictional character found in L. Frank Baum's Land of Oz.  Cap'n Bill and his friend Trot were introduced in Baum's fantasy novels "The Sea Fairies" (1911) and "Sky Island" (1912).  They first appear in Oz in "The Scarecrow of Oz" (1915), the ninth book in the Oz series. 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 Marvelous Land of Oz: Being an Account of the Further Adventures of the Scarecrow and the Tin Woodman, commonly shortened to The Land of Oz, published on July 5, 1904 , is the second of L. Frank Baum's books set in the Land of Oz, and the sequel to "The Wonderful Wizard of Oz" (1900).  This and the next 34 Oz books of the famous 40 were illustrated by John R. Neill.  The book was made into an episode of "The Shirley Temple Show" in 1960, and into a Canada/Japan co-produced animated series of the same name in 1986.  It was also adapted in comic book form by Marvel Comics, with the first issue being released in November 2009.  Plot elements from "The Marvelous Land of Oz" are included in the 1985 Disney feature film "Return to Oz".
Answer: John R. Neill