'Superworm': release date, voice cast, plot, and everything we know

Matt Smith voices Superworm. (Image credit: BBC/Magic Light Pictures)

Superworm is a new half-hour animated film based on the book written by Julia Donaldson and illustrated by Axel Scheffler.

It’s become something of a Christmas TV tradition for the BBC to adapt a work by Julia Donaldson for the festive season — previously there have been versions of The Gruffalo, The Snail and the Whale, and Zog to name a few.

Now Superworm is getting the same treatment. Olivia Colman, who acts as the narrator, says: “I was excited to play the narrator because I love all the Julia Donaldson books. I’ve read them to my children over the years and I love watching them at Christmas time when they’re on the telly. So I was thrilled that [Magic Light] asked me.

"The films are just lovely and they come out at the time of year when you can all be cosy and at home and watching something together.”

Here's everything we know...

'Superworm' release date

Superworm will be screened on Christmas Day on BBC1 at 2.30pm and will stream on BBC iPlayer the same day.

See our Christmas TV guide for all the festive highlights.

What’s the plot of 'Superworm'?

Superworm and the Wizard Lizard

Yikes! Superworm is in trouble!! (Image credit: BBC/Magic Light Pictures)

"Superworm is super-long. Superworm is super-strong. Watch him wiggle! See him squirm! Hip, hip, hooray for SUPERWORM!"

Yep, Superworm is starting to get a big too big for his boots (if he had any!). He’s been friends with Butterfly since he was small and she was a caterpillar. But Superworm has been boasting a bit too much and now the evil Wizard Lizard has heard about his powers. He decides to send his henchman, the Crow, to kidnap Superworm! Wizard Lizard wants to use Superworm to find buried treasure, will his dastardly plan work?

'Superworm' voice cast

Joining Olivia Colman as the narrator is ex Doctor Who star Matt Smith as Superworm. 

Speaking of his role as Superworm, Matt said: “I think you always warm to stories about friendship and this is a very charming tale of friendship and self-understanding for one small worm. There's a charm, there's a wit, and there's a lightness of touch and hopefulness that fits really well into Christmas Day... I’ve never done an animation, and I read this and I thought it was sweet and interesting and fun."

Gavin and Stacey star Rob Brydon voices Crow: "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.”


Patricia Alison will provide the voice for Butterfly.  (Image credit: BBC/Magic Light Pictures)

Kobna Holdbrook-Smith is Wizard Lizard: “Playing Wizard Lizard was a lot of fun. He’s a really self-indulgent baddie, which gives me joy, and it offers ample opportunity to be playful with the voice. Definitely a Christmas treat for me."

Speaking on her role as Butterfly, Patricia Alison said: “The Magic Light animations are such an important part of the Christmas TV schedule, I’m so excited to be part of that tradition. Butterfly is a very determined character, and a loyal friend, and I’m looking forward to seeing her on BBC One on Christmas Day".

Finally, Cariad Lloyd takes on multiple voices: "I absolutely adore working with Magic Light on these Donaldson/Scheffler adaptations, as much as I love watching them on television when they’re finished. They perfectly capture the magic of the story books whilst transporting you even deeper into the magical world that Julia and Axel have created. This year’s adaptation of Superworm is as joyous and funny as ever".

Is there a trailer?

Yes! The trailer starts off with Superworm doing all sorts of heroic things like saving a frog from being squashed by a passing car, but as his friends are celebrating everything that is 'super' about Superworm, Wizard Lizard can be seen plotting to kidnap him. Soon it is a race against time for Superworm's friends to rescue him... but will they succeed? 

David Hollingsworth

David is the What To Watch Editor and has over 20 years of experience in television journalism. He is currently writing about the latest television and film news for What To Watch.

Before working for What To Watch, David spent many years on TV Times magazine, interviewing some of television's most famous stars including Hollywood actor Kiefer Sutherland, singer Lionel Richie and wildlife legend Sir David Attenborough. 

David started out as a writer on TV Times before becoming the title's deputy features editor and then features editor. During his time on TV Times, David also helped run the annual TV Times Awards. David is a huge Death in Paradise fan, although he's still failed to solve a case before the show's detective! He also loves James Bond and controversially thinks that Timothy Dalton was an excellent 007.

Other than watching and writing about telly, David loves playing cricket, going to the cinema, trying to improve his tennis and chasing about after his kids!