This is not a drill: Benedict Cumberbatch and David Tennant are finally going to feature in the same show – though it's not a Doctor Who x Sherlock crossover!

It's just been announced that Cumberbatch will provide the voice of a "giant, animated Satan" who is "400ft high" in Good Omens, the new miniseries from American Gods' Neil Gaiman, which stars Tennant and Michael Sheen.

The casting news was shared at a TCA panel by Gaiman, who is heading up the project as showrunner. According to ET, he joked: "It’s a giant animated Satan. He turns up and we needed a performance that works. So we found a young British help that needed a lot of direction from Douglas [Mackinnon, series director]… Benedict Cumberbatch."

He then added, a little more respectfully: "As many of you know, Frances McDormand is playing God in this. And we suddenly realized we have Satan turning up in episode six, and we needed somebody who could give Frances McDormand a run for her money."

In the six-parter adapted from a novel co-written by Gaiman and the late Terry Pratchett, Tennant's demon Crowley and Sheen's angel Aziraphale are unlikely besties who team up to prevent the coming of the Antichrist.

The show's all-star cast also includes Miranda Richardson, Jon Hamm, Anna Maxwell Martin, Jack Whitehall, Nick Offerman, and Sir Derek Jacobi. The first trailer, which introduces us to the sparky Tennant-Sheen dynamic, debuted at New York Comic-Con in October.

Cumberbatch's supersize Satan will appear in the final episode of the six-part miniseries, which is due to debut in full on Amazon Prime on May 31.

Are you excited for Good Omens?