Kate Beckinsale Catherine
Robin Williams Dennis the Dog (voice)
Simon Pegg Neil Clarke
Terry Gilliam Nasty Alien (voice)
John Cleese Chief Alien (voice)
Suzy Eddie Izzard Headmaster
Joanna Lumley Fenella
Rob Riggle Grant
Michael Palin Kindly Alien (voice)
Eric Idle Salubrious Gat (voice)
Meera Syal Fiona
Sanjeev Bhaskar Ray
Bill Jones Producer
Emma Pierson Miss Pringle
Gavin Scott Newsreader, Screenplay
Professor Brian Cox Self
Alexa Davies Sandwich Girl
James Acheson Costume Design, Production Design
Mike Medavoy Executive Producer
David Annen Newsreader
James Kermack Policeman
Judy Loe Canteen Lady
Irene Lamb Casting
Jud Charlton Mortician
Naomi Moore Set Decoration
Jennifer Bell Hairstylist
Lucy Cork Stunt Double
George Fenton Original Music Composer
Ronan Summers Security Man
Robert Bathurst James Cleverill
Terry Jones Director, Scientist Alien (voice) / Van Driver, Writer
Marianne Oldham Rosie
Peter Hannan Director of Photography
Neville Phillips Author
Matt Fidler Animation
Beranger Maurice Animation
John Kay Animation
Oriol Navarro Animation
Ben Timlett Producer
Julian Rodd Editor
Lennon Clarke Bank Robber
Martyn Smith Animation
Mairi McHaffie Newsreader
Du Wenlong Animation
Rob Hemmings Animation Director
Tan Weijian Animation
Dong Yixue Animation
Xu Yueyuan Animation
Xie Liyan Animation
Li Jingxin Animation
Sun Xiaoxuan Animation
Yan Yan Animation