Willy Wonka & the Chocolate Factory too much emphasis on Willy Wonka and not enough on Charlie", as well as the casting of Gene Wilder instead of Spike Milligan. Dahl was also "infuriated" by the deviations in the plot Seltzer devised in his draft of the screenplay, including the conversion of Slugworth, a minor character in the book, into a spy (so that the film could have a villain) and the "fizzy lifting drinks" scene along with music other than the original Oompa Loompa compositions (including "Pure Imagination" and "The Candy Man"), and the ending dialogue for the movie. In 1996, Dahl's second wife, Felicity, commented
Willy Wonka & the Chocolate Factory to buy the rights to the book and finance the picture for the purpose of promoting a new Quaker Oats "Wonka Bar". David L. Wolper and Roald Dahl agreed that the film would be a children's musical, and that Dahl himself would write the screenplay. However, Wolper changed the title to "Willy Wonka and the Chocolate Factory". Screenwriter David Seltzer conceived a gimmick exclusively for the film that had Wonka quoting numerous literary sources, such as Arthur O'Shaughnessy's "Ode", Oscar Wilde's "The Importance of Being Earnest", Samuel Taylor Coleridge's "The Rime of the Ancient Mariner" and William Shakespeare's "The Merchant