Steven Spielberg bought the rights to the original book in 1991, when he apparently thought about making a traditionally animated film based on the book with Bill Murray as Shrek and Steve Martin as Donkey. After only a few years in development, producer John H. Williams got hold of the book from his children, and when he brought it to DreamWorks, it caught Jeffrey Katzenberg's attention and the studio decided to make it into a movie. After buying the rights to the film in 1995, Katzenberg quickly put the film in active development.