English comic actor Matt Berry describes the level of improvisation afforded to him and the cast of FX’s hit comedy “What We Do in the Shadows,” in which four vampires and a human familiar share a house on suburban Staten Island, as “very generous.” That freedom to “go for the most outrageous thing,” he says, is one reason why his justly admired performance as vaingloriously pervy 300-year-old bloodsucker Laszlo Cravensworth earned him an Emmy nomination for lead actor in a comedy. It’s a first for Berry, who also has won U.S. fans with such imported Britcoms as “The IT Crowd” and “Toast of London,” a show he co-created about an arrogant actor.

But before he filmed one episode of “Shadows,” one of Berry’s ideas was met with serious resistance by creator Jemaine Clement and executive producer Taika Waititi. “I offered at the beginning to do a sort of Eastern European accent, what you always associate with vampires,” he recalls, then imitates the pair’s reaction — “no, no, no, no, no, no, no, no, no, no” — with a deadpan calm that slyly conveys exactly how horrified Clement and Waititi would have been to lose one of the more priceless gifts in present-day comedy: Berry’s epically plummy, theatrically swaggering English baritone. “And so I have my own accent,” he says, adding, “on the keen enthusiasm from the creators.”

I should first clarify for readers that in real life you don’t speak like the ghost of every British stage ham converged into one larynx. But it’s not that far away, either.

To me, it doesn’t sound anything exceptional, because I’ve had it all my life. When I was younger, it made me laugh if I heard someone with a clipped accent be pompous. I’d instantly mimic it. It’s rare to hear now. Maybe some members of the royal family, but not your average citizen.

When you’re revving it up, is there anyone in particular you’re thinking of?

An actor called Jon Finch [who] had an incredible delivery. Even when doing everyday things, he sounds like he’s doing Shakespeare. And Tom Baker.

… Who is most well known for playing Doctor Who in the ’70s.

When I was a kid watching [Baker], I thought he was terrifying, the way he sounded. As I’ve become an actor, I’ve realized a lot of it was down to the fact that he was trying to remember his lines. He would start every sentence with [affects a deeply throaty sound] “We-e-e-lll …” and then he’d launch into whatever he was doing. That I find really funny. And I find anyone who is not particularly self-aware very amusing.

The sets for the series, says Matt Berry, are “so good, you forget you’re in a warehouse in Canada. You really are in this turn-of-the-century mansion full of furniture from the last 700 years.”

Laszlo certainly qualifies. Do those showy Victorian threads help put you into his ancient-and-randy mindset?

It’s also the sets. They’re so good, you forget you’re in a warehouse in Canada. You really are in this turn-of-the-century mansion full of furniture from the last 700 years. Because they’re vampires, they don’t get rid of anything. It’s so kind of warm and inviting, you want to stay there. Because outside is a warehouse and, you know, three feet of snow.

Is there a vampire power you’d take?

It wouldn’t be immortality. As you can see from them, it doesn’t look fun. And if you suffer from a mental health issue, you’ve got that forever. But they have no real interest in material things. That’s what I like. They couldn’t give a f— about things around them, or technology. That’s what I envy about them.

A very human power you have is musical ability. You’ve released many albums, and you’ve been a musician longer than you’ve been acting. Didn’t it play a part in how you were discovered?

I was playing singer-songwriter-type songs, and for a comedy club above a pub, I turned it into a character who was actually a serial killer confessing in his songs what he’d done. I thought it was hilarious. Matt Holness and Richard Ayoade saw me, and they were looking for someone to play a doctor in the TV version of their Edinburgh show, which became “Garth Marenghi’s Darkplace.”

That spoof of ’80s-era horror television, which first ran in the U.K. in 2004, became a cult comedy classic.

I’m so thankful for it every day. I’ve worked ever since, which is a complete and utter mystery.

What can we expect from the final season of “Shadows,” coming this October?

There are some clever things with the finale that I hope people will be really into. I’d be into it if I had nothing to do with it. Don’t get me wrong — nothing to do with me. The concepts, I think, are interesting, as opposed to watching myself. I must make that clear.

It’s funny how, being so expert at playing grand narcissists, you retreat from the merest hint of self-promotion.

That’s a British thing, I suppose, isn’t it? We largely don’t like to blast our own horns outwardly.