"City of Ember" is a 2008 young-adult movie, starring Tim Robbins and Bill Murray, which features an underground post-apocalyptic city where survivors are given specific jobs once they reach a certain age. Two teens find a mysterious box with a map to the surface and end up on the run from a corrupt Mayor and his henchmen. Reviewers at RogerEbert.com note that despite having a decent story and cast, the movie itself was a critical failure.
Based on a novel by Jeanne DuPrau, "City of Ember" is the first of four novels in the "Books of Ember" series. The movie stayed faithful to the novel's story, despite cutting out some minor events. According to a comparison at Prezi.com, the movie changed a few plot-devices, such as an invention by the main character's father.
Towards the end of the final act, a character encounters a fictional, giant version of a real-world animal, the star-nosed mole. While the movie depicted the animal being as large as a bear, in reality an adult mole only grows to about eight inches. However, the movie accurately depicted the 22 tentacles that protrude from the mole's nose, making it a terrifying monster to reveal at the end of the movie.