Steven Moffat and Mark Gatiss, the Sherlock creators who have now turned their hand to a reimagining of Dracula, have revealed that their gruesomely gothic creation all started with a joke at the expense of Benedict Cumberbatch.

Speaking at the premiere of Dracula in London this week, Gatiss said he took a silhouetted picture of Cumberbatch sporting his Sherlock Holmes coat with his collar up, and remarked that it resembled the blood-sucking Count.

He showed the shot to then BBC drama controller Ben Stephenson, who joked that Gatiss and Moffat should make a Dracula drama. “I said, ‘It looks like Dracula, doesn’t it?’ and he said, ‘Do you wanna do it?'” Gatiss explained, adding that they “just kept coming back” to the idea over the years.

Moffat added: “We talked about it as almost a jokey thing. We’d done Sherlock Holmes and the second most filmed character as we make our way down the list of plagiarism, was Dracula. As we talked about it, we started having ideas that we thought were quite good. It got to the point where we thought we should take this seriously.”

Dracula launches on BBC One on New Year’s Day before making its way over to Netflix globally. It’s a gothic reimagining of Bram Stoker’s 1897 story about a Transylvanian vampire who moves to England to find new blood. Gatiss said that after the Twilight phenomenon it “felt right” going back to the gothic roots of vampire stories with “big castles and moonlight and caves.”

One of the key differences in Moffat and Gatiss’ version, however, is they wanted to make Dracula less of a shadowy figure and more a central part of the story. “The big challenge we set ourselves was to make Dracula the central character in his own story for the first time. What’s it like as the anti-hero? What you have to give him is a personality which spans four centuries… You don’t want him to be just a shadowy presence,” Gatiss told an audience at the BFI screening.

Dracula is played by Danish actor Claes Bang, best known for his work in 2017 film The Square. Moffat said they had a clear set of instructions for casting director Kate Rhodes-James about who they wanted to play the iconic character.

He explained: “We needed somebody tall, dark, handsome, 40s, not wildly known for any particular role [and] not English, which is a very tall order. She sent through the list with name Claes Bang circled, partly just to say, ‘What a funny name.’ Kate sent a little link to The Square, which is brilliant. I clicked and immediately I was like, ‘That’s Dracula, we’re done.'” Gatiss added: “We were looking for an otherness and Claes has it spades. He’s incredibly tall, dark, handsome and other.”

Bang was not so sure about the idea at first. His initial response was, “Does the world really need one more Dracula?” but was eventually won over by Moffat and Gatiss’ script. “I read the script and then I was like, ‘Ok, sure.’ It is such a brilliant and new take on Dracula,” he added.

The end result is an uproariously gothic creation that does not pull any punches in the horror stakes. Bang is magnetic in the central role, dancing between menace and flickering humor. Moffat said the aim is for audiences to be laughing one minute and grossing out the next.

“We have a joint feeling that if the scene isn’t anything else, it should be funny. You can bury important plot information in a joke. You’re really setting them up for a sucker-punch if you make them laugh fondly and then chop someone’s head off,” he joked.