Matt Lucas is to play the twin of comic Harry Hill as the madcap TV Burp star makes his movie debut.
Filming begins this weekend on The Harry Hill Movie in which the big-collared comic heads off on a road trip to Blackpool after he learns his hamster has only a week to live.
Also featuring in the film are Sheridan Smith, Inbetweeners star Simon Bird and Julie Walters, who will play Harry's petrol-drinking nan.
During their travels, Harry and Julie are pursued by a mad vet (played by Simon), and come across pop band The Magic Numbers who have opened a B&B, before a climactic showdown at the top of Blackpool Tower.
Other names in the cast include Julian Barratt from The Mighty Boosh and Oscar winner Jim Broadbent, with Little Britain star Matt playing evil twin Otto.
Harry has co-written the script and will film the comedy around the UK over the next eight weeks.
He said: "I'm thrilled at last to be able to tell the world the true story of my hamster's struggle on the big screen and even more excited to be working with some of the comedy greats of the British film industry."
Producer Robert Jones, who was behind films such as Run, Fatboy, Run said: "It is an honour indeed to be able to help Harry bring a story so close to his heart to the public at large, many of whom will personally identify with the events depicted."
It is expected to be released before the end of the year.