1982 version
In 1982, the animated film The Secret of NIMH was released, directed by Don Bluth; it was his first feature film outside of Walt Disney Animation Studios. The film adds a mystical element completely absent from the novel, with Nicodemus portrayed as a wise, bearded old wizard with magic powers and an enchanted amulet, rather than an equal of the other rats. The character of Jenner is made a villain who is still present with the rats, rather than having left them before the story begins. The crow Jeremy has much greater prominence as comic relief in the film than he has in the book. Additionally, the Frisby family name was changed to "Brisby" to avoid trademark infringement with the Frisbee.[13]
Live-action/animated reboot
In 2009, Paramount Pictures set Neil Burger to write the script and Cary Granat to produce the film based on the book.[14] Nothing has materialised since and the rights to the book lapsed.
In 2015, MGM, which had released the 1982 film, acquired the rights to the book to adapt it into a live-action/animated film. Michael Berg was set to adapt it, while Daniel Bobker and Ehren Kruger were attached to produce.[15]
The Russo brothers were set as executive producers of the remake as of April 2019.[16]
Television series
A television series based on the books was in development at Fox as an event series in September 2021.[17]
