Game Of Thrones star Lena Headey is having a change of scenery from the bloodthirsty fantasy drama for a more innocent tale – playing a US secret agent in the new version of classic kids’ cartoon Danger Mouse.

The actress, who plays the scheming Cersei Lannister in the hit show, will voice the character of Jeopardy Mouse in the cartoon.

Jeopardy Mouse voiced by Game of Thrones star Lena Headey
(Valerie Taylor PR/PA)

She said: “I wanted to do it because it was pure nostalgia for me. I have children now and it’s just a treat to be involved in something that you loved as a kid and be able to share it.

“Those moments as an actor that come along once in while are not to be missed.”

Lena Headey
(David Crotty/AP/PA)

Lena is joined in the cast by talk show host John Oliver who will play-mad scientist wolf Dr Augustus P Crumhorn III.

John, who rose to fame in the US on The Daily Show with Jon Stewart, said he had loved the show “my whole life”.

He said: “Danger Mouse was a significant part of my childhood. So to get a chance to do it is like getting a chance to step into your childhood, which is both a magical and a potentially hazardous thing. It will be awesome, I can’t wait to see it, let alone hear myself in it.”

John Oliver
(Richard Shotwell/AP/PA)

The casting was announced at Comic-Con in the United States where programme makers also revealed the show would feature an appearance from spin-off character Count Duckula.

The CBBC show features Alexander Armstrong as the voice of the world’s smallest secret agent Danger Mouse, Kevin Eldon as his sidekick Penfold, Stephen Fry as Colonel K and Dave Lamb as the narrator.