Walliams himself will also feature in the story he first wrote in 2008. He said, “We have put together a dream cast for this the first of my children’s books and for many still my best. It is a funny and poignant story about what is is to be different. I hope it will make everyone who sees it, young and old, stop and think.”
Walliams and Moss have starred on screen together before, appearing in a Comic Relief special in 2013.
Young actor Billy Kennedy will make his TV debut as Dennis, in the third festive comedy to be based on Walliams’s childrens’ books.