A film about a fantasist fish isn’t the most obvious subject for Christmas Day – except when it’s based on a children’s story by prolific British author Julia Donaldson and her longtime illustrator Axel Scheffler.

“Tiddler” is the twelfth of Donaldson and Scheffler’s collaborations to be adapted by U.K. production company Magic Light Pictures and, in keeping with previous adaptations, boasts an all-star voice cast, including “Ted Lasso’s” Hannah Waddingham as the narrator. (Last month Waddingham was in attendance at a special screening of the film, held at an aquarium in London).

Speaking at a press event in November, Donaldson said the book, which is also called “Tiddler,” features one of her favorite plot devices, in which Tiddler – a naughty school-aged fish who is always late for class because he’s dreaming up “tall tales” – is accidentally kidnapped before finding his way home by tracing his own story through the various undersea creatures who have heard it. “I think actually it’s the best moment in my whole writing career when I thought of that idea,” Donaldson said.

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Hannah Waddingham at a screening of ‘Tiddler’ in London (courtesy of Magic Light Pictures) Magic Light/Goff Photos

“That came in a flash, that he would find his way home by following his own stories through the ocean,” she continued. “So I was really proud of that idea because it’s kind of the opposite of ‘The Boy Who Cried Wolf.’ You know, in ‘The Boy Who Cried Wolf’ you’re taught ‘Don’t tell a story’ and it’s the downfall of the boy who cries wolf because no one believes him when the real wolf comes along. And [in ‘Tiddler’], the moral is, do tell stories. Make things up. I wouldn’t say lie exactly but it is a celebration of the imagination.”

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In the film adaptation of “Tiddler,” which airs in the U.K. on the BBC and iPlayer on Dec. 25, storytelling through drawing is also given a starring role. The screen version goes deeper than the book into the character of Tiddler’s friend Johnny Dory, showing him to be a talented illustrator. “I think it’s lovely the way in this adaptation, they’re not just celebrating story-writing but illustration,” Donaldson said of the change to the source material.

For executive producer and Magic Light co-founder Martin Pope, who has produced all of the company’s Donaldson and Scheffler adaptations (starting with Helena Bonham Carter and James Corden-voiced “The Gruffalo” in 2009), the joy of “Tiddler” is that it’s “about the power of storytelling, which is a wonderful thing to celebrate.”

“Embrace stories. Listen to your children. Tell them lots and lots of stories,” Pope added. “It’s a wonderful thing to be able to tell stories. That’s why we celebrate these two marvelous creators [Donaldson and Scheffler], is because of their stories, it’s a wonderful thing.”

After hearing both Donaldson and Pope wax lyrical about encouraging children to tell stories, Scheffler, whose acerbic European humor belies his deep connection with both his work and his decades-long partnership with Donaldson, wryly interjected: “You’re not worried that the whole nation, all the children, will be late for school and tell stories?”

Pope was unperturbed about the prospect. “My wife’s a teacher,” he quipped. “Lots of them are late anyway.”

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