TV’s latest set of vampires kill a lot of people in gruesome fashion. They’re frightening to look at. They threaten the existence of humanity.

But mostly, they’re hilarious.

“What We Do in the Shadows,” which premieres Wednesday on FX, is one of the strangest things to hit TV this season. Based on the 2014 movie of the same title, it’s about four vampires who share a home on Staten Island. Housemates for centuries, they’re clearly on each others’ nerves.

“Last night, there were all the people down there, shouting and screaming, half drunk,” says Nandor (Kayvan Novak), the self-appointed leader.

“Well, where did they find the alcohol?” Laszlo (Matt Berry) asks.

“No, they were half drunk. They’d been half drunk,” Nandor replies. “Please finish a whole victim before moving on to a next one, OK? It’s very unhygienic. I think I know who’s leaving them down there, but I don’t want to say.”

That’s followed by bared fangs and a midair vampire battle, until Nadja (Natasia Demetriou) offers a solution.

“Why don’t we just write on them with marker pens? Put our names and a date,” she suggests.

It’s completely bizarre and outrageously funny.

Executive producers/writers/directors Jemaine Clement (“Flight of the Conchords”) and Taika Waititi (who directed “Thor: Ragnorak”) starred in the movie; they’re off-camera this time.

If you haven’t seen the movie, you’re not alone. It premiered at the Sundance Film Festival in 2014, and earned just $6.9 million at the box office in a limited release a year later — which makes it all the more unlikely that it’s been turned into a TV show.

“It’s not like this was some huge blockbuster movie and it was an attempt to cash in,” said executive producer Paul Simms. “It was a little cult movie that people really loved, and FX was, like, ‘All right. Make a TV version of it.’ It’s a labor of love.”

And it’s incredibly dumb, in absolutely the best way. Nothing has made me laugh this much in a long time. Harvey Guillen gets laughs, sometimes without even speaking, in the role of Nandor’s vampire-wannabe familiar — who’s “a little too familiar” at times for Nandor’s liking.

(“What We Do in the Shadows” is intended for adults. The series contains violence and R-rated language.)

The TV series features entirely new set of characters — and an entirely new cast — but it follows the same formula seen in the movie. They’re playing with the conceit that has powered everything from “The Office” to “Modern Family” to “Arrested Development” — it’s a mockumentary with an off-camera documentary film crew.

“I picture it like this documentary crew is making a film that no one watches,” Clement said.

And having a faux documentary crew sort of hides the imperfections. Or, maybe, makes the imperfections work. “You want [the vampires] to be stumbling over their lines, talking over the top of each other so it doesn’t feel like it’s read or it doesn’t feel like it’s acting,” Waititi said.

It’s all scripted, for the most part, but the actors do improvise at times — and some of that improvisation makes it into the episodes. That includes sequences with the “energy vampire” — an addition that was not in the film. Mark Prosch stars as Colin, a nebbishy guy who annoys and bores the people around him, sucking out their life force.

“You meet a lot of those kind of people at parties,” Clement said. “You just get trapped.”

Clement and Waititi decided that was a real “supernatural” power, and discovered Prosch “can improvise, it seems like, for infinity,” Clement said, with “just boring subject matter.”

Prosch calls it his “babbling brook of bulls---.”

It’s part of the weirdness that works — characters and situations that are much funnier on film than they must have seemed on paper. Or than they seem in a description of the show. Although I’ll share one more bit of dialogue from the pilot that made me laugh out loud:

“I was the most handsome man in our village,” Laszlo says.

“His village was very badly affected by leprosy and plague,” Nadja adds.

“What We Do in the Shadows” airs Wednesdays on FX — 8 p.m. on DirecTV and Dish; 11 p.m. on Comcast.