Mrs. Brisby's Adventures of Shrek is an upcoming crossover film.
In the story - Mrs. Brisby and Jeremy encountered a grouchy but good hearted ogre who lived alone in a swamp. With help from a friendly Donkey - Shrek will do whatever it takes to rescue Princess Fiona from the evil Lord Farquaad.
The guest stars in this film will be Bernard Bianca and Ratigan.