When Emily and Alexander give birth to their son,he must choose if he wants to live in the country or the city.
- Lucas Cruiskank as Ratz Mouse, and the main protagonist of the film.
- Michael Aspel as Alexander Mouse
- Sandra Kerr as Emily Mouse
- Dane Boedigheimer as Hawk the Octopus, the main antagonist of the film.
- Clive Revill as The Chairmouse
- Clive James as Oscar the Bird
- Ade Edmondson as No-Tail No-Goodnik
- Cat Deeley as Emily's Mother
- Harry Hill as Emily's Father
- Pixie Lott as Duchess the Whale
- Ricky Gervais as Bradley the Shark
- John Cleese as Gross
- Michael Palin as Duke
- Terry Jones as Sally Mae
- Eric Idle as Alive Eye
- Terry Gilliam as Dead Owl
- Graham Chapman as Red Mole (archive sound)
- Jonathan Hyde as Joe the Seal
- John Larroguette as Jack the Seal
- Tress MacNeille as Aunt Maude
- Janyse Jaud as Wendy Winkle
- Penelope Keith as Pigeon 1
- Mindy Cohn as Pigeon 2
- Susie Blake as Pigeon 3
- The film will be also released in Real3D and Digital3D formats. It will be digitally remastered into IMAX format and released in select theaters across Europe, Asia, the Middle East and Latin America.
- Theatrically, the film was accompanied by the Shires Animation Studios short film, Marina: Gone Fishing.
- The film was rated PG-13 for fantasy violence, thematic elements and brief use of language - all involving animals.
- The animation is produced by Mikros Image and Reel FX Creative Studios.
- This is the fourth Shires Animation Studios feature to have the "Created and Produced at Shires Animation Studios, www.shires.com" credit at the end.
- The third film with the Shires logo under the movie title.
- This is the second Shires Animation Studios film to feature the full 2011 Shires opening logo as a closing logo.
- This is the fourth Shires movie to have the title card appear both at the start and at the end (before the credits).