Christmas has come early for two young North Wales actors who’ve landed dream roles as a pair of mischievous twins with secret super powers in a hit S4C show.

Moi Williams, from Caernarfon, and Lowri Llewelyn from Bangor, both 10, beat more than 600 other hopefuls to clinch the parts of Deian and Loli in the hugely popular series of the same name.

They are taking over from Ifan Henri, 11, who lives in Abersoch, and Lleucu Owain, 12, from Cerrigydrudion, near Corwen, who are bowing out after outgrowing the characters.

The new duo will be making their debut when the changeover happens during a special Christmas episode that will be broadcast during the festive period.

A bit like Dr Who, the whole cast is being regenerated with new actors because the twins’ parents also have fresh faces.

Sion Eifion, who hails from Llanfaelog near Rhosneigr and Fflur Medi Owen, from Tregarth near Bangor, are replacing Rhys ap Trefor and Sara Lloyd.

Filming is underway by Caernarfon-based TV production company Cwmni Da on the fourth series of the award-winning show which they make for S4C’s children’s platform, Cyw.

Deian and Loli have special powers in the show and by saying the magic word, “Ribidirew!”, they are able to freeze their parents while they go off on fantastic adventures.

By using giant green screens on the wall and floor of the studio, the production team   are able to project almost any picture as a background, with the help of special visual effects created in-house at Cwmni Da.

Shooting has also been taking part on location and cast and crew have been running around the woods in Parc Glynllifon near Caernarfon while scenes inside Deian a Loli’s home have been filmed in a village near Penygroes.

As well as having a legion of young, dedicated fans from across Wales, the show has also been a massive hit with television critics.

It has scooped numerous accolades including three BAFTA Cymru Awards and has been sold internationally, with several Deian Loli books being published by Y Lolfa.

Munching chocolate biscuits during a break in filming at Cwmni Da’s studio in the historic Goleuad building which once used to print dozens of weekly newspapers, Moi and Lowri said they were great fans of the previous series and were loving the experience of playing their idols.

Moi, a talented footballer who has played for the Bangor City Academy and supports Liverpool FC, said he had not done any acting before and apart from being on a Cyw challenge programme with his friends had never been in a television studio.

A pupil at Caernarfon’s Ysgol y Gelli, he said: “I’ve been to Ysgol Glanaethwy in Bangor and done some acting and singing there but nothing else. The green screen is much larger than I thought it would be but getting to grips with the acting is a challenge which I’m really enjoying.

“I’m getting used to the filming now and I really like the excitement of it.”

Unlike her co-star, Lowri, who attends Bangor’s Ysgol y Garnedd, does have some acting experience under her belt.

She said: “I’ve got three brothers and we have put on pantomimes and other shows at Easter for our parents and grandparents at home. But I’ve never done anything like this before.  I’m really enjoying it and think it’s great.”

According to director and co-producer Martin Thomas, 10 episodes were being made over the summer with another 10 planned for next year.

Martin said Lowri and Moi were settling into their new roles very well.

He added: “We’re in the second week of filming and they have brought a fresh energy into the show,

“It’s sad to see the former cast leave. We work with them for two years and become very close but like a phoenix another cast grows from the ashes and they bring something new to the table.”

Lleucu Owain and Ifan Henri, the two youngsters, who played the roles of Deian and Loli in the last series had wise words of advice for Lowri and Moi as their career as the likeable twins get underway.

Lleucu said: “I found the experience a very special one – every day on set was full of fun and laughter because the crew were all so friendly.

“All the stories were special and Loli had many adventures! It was a lot of fun to get to wear different things and get to act on the green screen. I was very lucky to be able to work at various sites and it was exciting to be able to film late at night at times!

“A word of advice I would offer to the new crew is to enjoy every moment!”

Ifan Henri added: “The time I had filming Deian and Loli was one of the best experiences I’ve ever had.

“It was a slightly different experience for Lleucu and me as it happened during the Covid period! I had a lot of fun and the crew and the other actors were all so friendly with us and helped us do the work.

“I enjoyed learning to act in front of a camera and also seeing how everyone works behind the camera.”