The Giggle (in-universe novelisation)

The Giggle, briefly retitled "The Toymaker and the Giggle", was a book that recounted the Fourteenth Doctor's battle with the Toymaker, told at least partially by James Goss, before being hijacked by the Toymaker himself. (PROSE: The Giggle ^[+]Loading...["The Giggle (novelisation)"])

Behind the scenes

The story seems to imply that, while the Toymaker wrote the novelisation in-universe, the book isn't necessarily commercially available there, but rather he wrote the real book, especially as the Toymaker gives no particular awareness of any sort of metafictional counterpart of the Doctor Who franchise existing in-universe.