Though Eichner screams at his contestants, he is, in his own way, being respectful. Illustration by Ben Kirchner

On a Friday night in February, in Greenpoint, Brooklyn, Billy Eichner, the thirty-seven-year-old star of the sui-generis pop-culture game show “Billy on the Street,” was sitting in a director’s chair on the set of the sitcom “Difficult People.” That show, about two struggling performers, a straight woman and a gay man, who are harsh about the world and affectionate with each other, was created and is written by the comedian Julie Klausner, with whom he co-stars. Eichner has excellent posture, even when looking at his phone. “I was a ‘Jeopardy!’ question this week,” he told me. He held up a screen shot of the clue: “GAMES OF THIS COMIC ‘ON THE STREET’ INCLUDED ‘WOULD DREW BARRYMORE LIKE THAT?’ & ‘IT’S SPOCK! DO YOU CARE?’ ”

On “Billy,” now entering its fifth season, Eichner startles New Yorkers on the street and gets them to play games and answer questions, for weird prizes and small amounts of money. (A little girl who played a game called “ ‘Weekend at Bernie’s’ or ‘Django Unchained’?,” in which she had to identify which plot points came from which movie, won an enormous pair of jeans.) Sometimes Eichner runs around surprising people with a movie star in tow, like Zachary Quinto, of “Star Trek.” (“It’s Spock! Do you care?”) He creates fanciful obstacle courses, such as “Leah Remini’s Escape from Scientology,” in city parks and paved lots. He has made viral videos with Madonna, Julianne Moore, and David Letterman. Joan Rivers was a friend and a fan. On “Jeopardy!,” nobody knew who he was.

“I am responsible for something rare, which is three seconds of complete and utter silence on national television,” Eichner said, in reference to stumping the “Jeopardy!” panelists. “You won’t see that on ‘Fresh Off the Boat.’ ”

You won’t see that on “Billy on the Street,” either. Eichner is hyperliterate in the language of pop culture, asking rapid-fire questions about Kaley Cuoco or Meryl Streep before his guests know what’s happening to them. He’s a walking id, quick to rage or exult. He sighs a lot. He swears. When a contestant wins a prize—a dollar, a bag of Claire Danes-shaped Gummy Claires—Eichner jumps up and down, hollering with glee. Inevitably, the contestant does, too.

One of his signature moves is to turn to the camera, mid-conversation, and take his shout to a full-on roar, as if he’d absolutely had it. He used this technique when Michelle Obama appeared on “Billy on the Street,” last year, in a supermarket with Big Bird, to promote eating fruits and vegetables, via a game called “Ariana Grande or Eating a Carrot?” “You and your husband have such busy lives,” he said to Obama. He turned to the camera and shrieked, “To say the least! ” The First Lady looked startled. During the quiz, Eichner asked, “Who’s more deserving of a Kennedy Center Honor—Martin Short or a box of frozen corn?”

“The corn,” Obama said.

“No, Martin Short! ” Eichner yelled in exasperation. Obama doubled over, laughing. Eichner said, “He’s a genius! He played Ed Grimley.”

“I like corn,” Obama said.

Eichner was a New York cult hero before he was a national cult hero. Amy Poehler, the executive producer of “Difficult People,” told me, “Billy and Julie have both felt like outsiders, and it’s sharpened their writing and performing. It’s like the grain of sand in the oyster.”

“People come up to me all the time and say, ‘I just found out about you!’ ” Eichner said. “Part of me is happy and part of me is, like, Where the hell have you been?”

Eichner is six feet three and fit, with broad shoulders. On “Billy on the Street,” he wears a hoodie, jeans, and a T-shirt. He has a handsome face, with a slight asymmetry around the eyes. His height, his big microphone, his pronounced widow’s peak, the screaming: the over-all effect is commanding, and a little unnerving. On his first appearance on “Conan,” in January, 2012, he ranted about Johnny Depp. “He’s quirky and he’s pretty and he’s quirky and he’s pretty! ” he yelled, raising and lowering his hands. “You know what? Why don’t you just be pretty, and leave quirky to those of us who don’t have a choice! ” He jabbed at his chest like a jackhammer.

On “Billy on the Street,” Eichner’s lifelong love of show business, musical theatre, independent films, seriocomic dramas made for adults, the people who make them, and absurdity in general play out on the sidewalks of New York. He’s fascinated by pop culture and fatigued by the hype surrounding it. He asks people about entertainment-world minutiae with the intensity of a thousand suns; he brings megastars and civilians together in strange, humble scenarios; when a contestant’s answer upsets him in one segment, he flops onto a mountain of garbage bags. In his ability to instigate and navigate all this, to will himself into stardom and to remain unfazed by it, and to confront us with fame’s magnitude and its inconsequence as we race to catch a bus, he is, perhaps, the ultimate New Yorker.

I first met Eichner this winter, when “Difficult People” was shooting at a restaurant in the East Village. He was filming a scene with Klausner and Andrea Martin, the Second City veteran, who plays Julie’s mother. (Klausner and Eichner’s characters are named Julie and Billy.) The growing niche success of “Billy” has helped increase Eichner’s mainstream success as an actor; in addition to “Difficult People,” he had a recurring role in the final two seasons of “Parks and Recreation.” Poehler said, “As a producer, I’m always trying to nudge Billy and Julie into real moments onscreen where we see them being vulnerable.” They are not, she pointed out, insult comedians. When Eichner and Klausner riff together, the show takes flight. In the first episode, Eichner ferociously mocks Chelsea Handler—“I’ve been so drunk for the last five years I haven’t written a joke!”—making Klausner burst into laughter tinged with shock that feels genuine. “We fought to keep that,” Eichner told me.

The day’s scene took place in the café where Billy works and Julie likes to write. Eichner stood by a monitor, studying a script. He plays a waiter, but in his struggling years that job didn’t pan out for him. “I waited tables at the Odeon for two days and was asked not to return,” he said. “I was a terrible waiter.” Bartending went better. “It was a position of power—a much sexier job than waiting tables. I bartended at Broadway shows. The V.I.P. lounge for members upstairs at the Roundabout—they had themed drinks, like the ‘Design for Living’-tini.”

Martin was across the room, waiting for her scene. Eichner said, “When Andrea started, I was full of questions—‘What’s Goldie Hawn like?’ ‘What was John Candy like?’ ” Improvising with her was intimidating, he said.

Before a scene in which Eichner would be observing from the sidelines as Klausner sat at a table talking to Martin and her campy gay friend, the director said, “The camera will be rolling on you, Billy. Just react as if you were part of the conversation.”