Olivia Colman, Matt Smith, and Rob Brydon are all landing their voices to new animation Superworm.

Colman will play the narrator, and Smith will voice the hero, Superworm. They are joined by Patricia Allison as Butterfly, and Rob Brydon as the Crow, with other cast to be announced later in the year.

The 30-minute film which will be shown on BBC One at Christmas.

The animation is based on another book by Julia Donaldson and Axel Scheffler – making this their ninth book to be turned into a festive treat by the BBC.

The story follows an heroic worm who finds himself in need of help when he’s captured by the Wizard Lizard.

Speaking about their roles, Olivia Colman said: “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 added: “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.”