The Cat in the Hat script, with Chris Meledandri as producer, and Audrey Geisel as the executive producer. However, the project never came to fruition. On January 24, 2018, it was announced that Warner Animation Group was in development of a different animated "Cat in the Hat" film as part of a creative partnership with Seuss Enterprises. In 2009, the Royal National Theatre created a stage version of the book, adapted and directed by Katie Mitchell. "Seussical", a musical adaptation that incorporates aspects of many Dr. Seuss works, features the Cat in the Hat as narrator. The musical received weak reviews when it opened, in
The Cat in the Hat read, and Spaulding provided Geisel with a similar list. Geisel later told biographers Judith and Neil Morgan that Spaulding had supplied him with a list of 348 words that every six-year-old should know and insisted that the book's vocabulary be limited to 225 words. However, according to Philip Nel, Geisel gave varying numbers in interviews from 1964 to 1969. He variously claimed that he could use between 200 and 250 words from a list of between 300 and 400; the finished book contains 236 different words. Geisel gave varying accounts of how he conceived of "The Cat in the Hat".