Stars Olivia Colman and Matt Smith lead the cast of Superworm, coming to BBC One and BBC iPlayer for Christmas 2021

Superworm is a hero with a difference. Super-long and super-strong, he's always on hand to help out all the other animals and insects - whether he's saving baby toad from an accident, rescuing beetle from falling down a well, or even good-naturedly offering himself up as a skipping rope for some bored bees. Superworm and his best friend Butterfly make a great team but Superworm too often takes all the credit. When the wicked Wizard Lizard hears about Superworm's special skills, he sends his servant Crow to kidnap Superworm. Despite everything, with her friend in deep trouble, Butterfly comes to the rescue, convincing the other creatures to help her with a daring plan…

The first-rate voice cast for the adaptation will be headlined by Oscar-winner Olivia Colman as narrator and Emmy nominee Matt Smith playing the hero, Superworm. They are joined by Patricia Allison (Sex Education) as Butterfly, and Rob Brydon (Gavin & Stacey) as the Crow, with other cast to be announced later in the year.

Olivia Colman says: "This is such a lovely project to be involved with. When reading the script, and imagining all those goings on at the end of the garden, I could really get a feel for the pure fun and joy that the film will bring. I've always loved these charming productions at Christmas and I'm delighted to be voicing the narrator."

Matt Smith says: "I'm delighted to play the part of Superworm! And join such a fabulous cast of actors, artists and storytellers. What fun to be part of the BBC's Christmas line up in this great children's tale."

Patricia Allison says: "The Magic Light animations are such an important part of the Christmas TV schedule, I'm excited to become part of that tradition. Butterfly is a very determined character, and a loyal friend, so I'm looking forward to recording a lot."

Rob Brydon, playing Crow, says: "This will be my ninth appearance in a Donaldson/ Scheffler adaptation. Working on these Magic Light productions is always a delight and deciding how to voice characters is such fun. I love watching them on TV at Christmas - a lovely way to round off my year."