The cast of Watership Down have shared the terror they felt as they watched the film’s original animated version as children.

James McAvoy, John Boyega, Gemma Arterton and Nicholas Hoult are among a star-studded cast voicing the rabbits in the BBC One version of the best-selling novel, which was famously adapted into a film in 1978.

McAvoy, who plays Hazel, said watching the original animation as a child had struck terror into him. Asked why he had taken the role in the reboot, the 39-year-old replied: “From the deep love and terror that watching the 1978 animation put inside my bones, and then from reading the novel later in life when it blew me away all over again.

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James McAvoy voices the rabbit Hazel in the BBC adaptation (Ian West/PA)

“I was excited by the opportunity to try to bring Watership Down to a new generation, on such a huge scale as has never been done before. I think it’s a story you can relive in any decade.”

Arterton, who plays naive hutch rabbit Clover, said she had been “petrified” by the “harrowing” original after watching it at a young age. The 32-year-old hailed the tale as a “classic” of British literature which had lessons to teach the public in environmentalism.

She said: “Watership Down is such a classic story in British literature. I remember seeing the 1978 animation when I was very young – and being petrified by it. Having revisited the story as an adult, it’s so pertinent, especially for these days and these times.”

Watership Down
Nicholas Hoult voices the rabbit Fiver, who experiences visions of the future (Ian West/PA)

She added: “I think in a way Watership Down is supposed to frighten people. On one level it’s a harrowing, wake-up call to get us to look at what we are doing to our environment and our society. I think without there being those elements, it wouldn’t have the impact that it has. I remember watching the 1978 film as a kid on telly and thinking it would be a lovely bunny rabbit film – and it’s not.

Hoult plays Fiver, who is able to see visions of the future and foretells the destruction of the rabbits’ home, Sandleford Warren. He said he had found his character’s nightmares especially ghoulish.

He said: “The story is scary at times. Particularly for me, watching Fiver’s nightmares, as they are fairly terrifying. But it’s all there for the story, and not unsuitable for your children to be watching with you.”

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Gemma Arterton takes on the voice of hutch rabbit Clover (Matt Crossick/PA)

Stars War actor Boyega, 26, described the original film as “devastating” but suggested the emotional stakes were higher now with the added realism that computer generated imagery allowed.

He added: “I was also curious as to how they were going to do this, because the 1978 film was in 2D and it was devastating. I was devastated, I can’t lie. It was too much – it was bloody and looked a bit strange and as a kid taking that in was very scary.

“But this version, whilst still animation, looks a lot more real now, and it’s so interesting to take that approach. With CG you can add a sense of reality, which increases the emotional stakes for those watching it.”

Watership Down will air as two feature-length episodes on BBC One on Saturday December 22 and Sunday December 23.