Rob Brydon voices a huge humpback whale as a tiny snail hitches a ride on its tail

He’s one of the busiest men on TV, but Rob Brydon never passes up the opportunity to voice a character in the Christmas adaptations of Julia Donaldson’s books. 

This year’s magical version of The Snail And The Whale, in which a tiny snail hitches a ride on a huge humpback whale’s tail to see the world, will be his sixth. 

‘It’s always been one of my favourite books,’ says Rob, who voices the whale alongside Sally Hawkins as the snail and Dame Diana Rigg as the narrator.  

This year's magical version of The Snail And The Whale, in which a tiny snail hitches a ride on a huge humpback whale's tail to see the world, will be shown on Christmas Day

This year's magical version of The Snail And The Whale, in which a tiny snail hitches a ride on a huge humpback whale's tail to see the world, will be shown on Christmas Day

This year’s magical version of The Snail And The Whale, in which a tiny snail hitches a ride on a huge humpback whale’s tail to see the world, will be shown on Christmas Day

‘I’ve got five children so I’ve clocked up a lot of children’s stories, and the good ones make it effortless. It’s only when you read a bad one that you notice. This book flows so well, Julia is a maestro with words.’ 

The film took two years to make, partly due to the difficulty of animating water and the way it acts with creatures gliding through it. 

The animators went whale watching and researched wildlife shows to see how the whale would look both under the water and above it. 

Another issue was scale. Even if snails really did crawl onto the tails of whales and swim around the world, the difference in their sizes would mean you never see them. 

He's one of the busiest men on TV, but Rob Brydon (pictured)never passes up the opportunity to voice a character in the Christmas adaptations of Julia Donaldson's books

He's one of the busiest men on TV, but Rob Brydon (pictured)never passes up the opportunity to voice a character in the Christmas adaptations of Julia Donaldson's books

He’s one of the busiest men on TV, but Rob Brydon (pictured)never passes up the opportunity to voice a character in the Christmas adaptations of Julia Donaldson’s books

Illustrator Axel Scheffler admits the only way around it was to cheat. 

‘Everything is zoologically incorrect, but that doesn’t matter because logic has gone out of the window,’ he admits. 

‘There’s a line in the book about the whale being ‘grey-blue’ while this one is technically black, but I hope people can forgive us for that too.’ 

The Snail And The Whale, Christmas Day, 2.30pm, BBC1.