NEW YORK, NY.- On a rainy morning in early August, actor Michael Cyril Creighton sat in a dog-friendly cafe on the outskirts of Astoria, Queens. With him was Sharon, his 7-year-old rescue, who is part Chihuahua, part Jack Russell terrier, with a soupçon of haunted doll. Another dog scampered over to their table. Sharon growled low in her throat and bared her teeth.

“She has a troubled past,” Creighton said, soothing her. “But she’s great.”

Creighton — bespectacled, bearded, with a cuddlesome physique — is more reliably sociable. During a two-hour conversation that began with savory scones and included a damp walk at a nearby sculpture park, he growled not once — not even when interrupted, frequently, by fans of his work on “Only Murders in the Building.”

In “Only Murders,” the Hulu series about occasional homicides in a luxury co-op on Manhattan’s Upper West Side, Creighton, 45, plays Howard, a librarian and hobbyist yodeler with an impressive sweater game. A gossip and a noodge, keen to be accepted by the building’s amateur detectives, a trio played by Selena Gomez, Steve Martin and Martin Short, Howard is also capable of surprising vulnerability. So is Creighton, who combines a mordant wit and a clown’s broad instincts with deep feeling.

A recurring actor in the show’s first two seasons, Creighton was made a series regular in its third. In Season 4, which premiered Tuesday, his co-stars include a pig who urinated on his feet between takes.

“Look, it’s ridiculous what we’ve got going on in his world,” John Hoffman, the “Only Murders” showrunner, said in an interview. “I feel like I can throw him anything, and he’ll sort it out. I can’t believe I got so lucky to find him.”

Creighton grew up on Long Island, the only child of a single mother in a close-knit Catholic family. No one in his immediate family was a performer, though a cousin had played a few small roles in movies. But theater, and the occasional Christmas pageant at his school, held a powerful attraction.

“When you’re young and gay and not sure where you fit in, there’s a lot of trial and error,” he said. “I landed in theater. It was the thing that was making me happy, keeping me afloat.”

After studying theater at Emerson College and losing his Long Island accent, he moved to the city, bouncing around off-off-Broadway. Early on, he met Hannah Bos and Paul Thureen, two of the founders of the theater company the Debate Society, and began working with them in delightful, idiosyncratic shows like “Buddy Cop 2” and “Blood Play.”

“It was really fun to write for him because he’s so funny, but he’s also so dark,” said Bos, now a showrunner on the bittersweet HBO comedy “Somebody Somewhere.” “He really finds these nuances in characters like no other person.”

During these years, he always held day jobs, including running the box office at the Playwrights Horizons theater in Manhattan. He channeled that experience into “Jack in a Box,” an award-winning web series that ran from 2009 to 2012 and co-starred Downtown luminaries like Cole Escola, Becca Blackwell and Jackie Hoffman.

“I needed to create for myself because I was afraid other people weren’t going to,” Creighton said. “When I was in college, they always said, ‘You’re a character actor; you won’t work till you’re in your 40s.’ And I was like, I am not waiting until my 40s. Are you kidding me?”

He was still working in the box office when he met a casting director, Katja Blichfeld, who found him a role in “30 Rock,” then cast him in her own show, “High Maintenance.” He played Patrick, a gentle agoraphobe with a crush on his weed dealer. That role crystallized Creighton’s singular mixture of comedy and vulnerability and hinted at his talent for making the outlandish seem achingly relatable.

At 34, he mustered up the courage and the savings to quit the box office. Almost immediately, he won a part in the Sarah Ruhl comedy “Stage Kiss,” at Playwrights Horizons’ main stage theater, in which he played an overeager understudy. That brought him better representation, and he was soon cast in “Spotlight,” playing an adult survivor of childhood clergy abuse. It was his first film role.

Even as his career kept growing, he was typically a day player, booking an episode here and there, a scene or two in a film. He didn’t mind much. He liked going around to different sets, observing how various directors and actors worked. But he wanted more.

“I also always crave to be part of something and to be tethered to something and to feel ownership over something,” he said.

On every set, he had a fantasy that the director would see his work and decide to keep his character. “Every time, every single part I have ever played, I have a three-episode arc in my head of how it could continue,” he said. That fantasy never came true, until “Only Murders.”

Creighton was cast via video calls when COVID was still at its height. (The Howard audition attracted “truthfully, the most amazing schlubs,” Hoffman said. Creighton was first among them.) Creighton shot his first episode, and then he caught COVID. He was better in time for his second, in which Gomez’s Mabel and Martin’s Charles confront Howard in his apartment. But out of an abundance of caution, Creighton was shot separately, in an empty room. He was disappointed, but he tried not to show it. He succeeded.

Hoffman quickly realized that Howard, in all of his spite and anguish, was as integral to the building as the masonry and that Creighton had a gift for humanizing a patently absurd character.

“He gives an unbelievably funny, dark, sad, funny performance the entire way through,” Hoffman said. “The cast just fell in love with him.” Martin, in an email, wrote: “Every time Michael is in a scene, I relax. Because I know the comedy is taken care of.”

This season, that comedy includes a retired working dog as well as the incontinent pig, as Howard attempts to enter the fraught world of podcasting himself with a show called “Animals and Their Jobs.” In the main arc, the three amateur detectives agree to a movie based on their adventures, and Howard auditions to play himself. “You make me want to vomit,” one of the movie’s directors says. He loses the part to Josh Gad.

“It feels weirdly right for Howard,” Creighton said.

“Only Murders” feels right for Creighton. He likes the consistency and he likes the recognition, except when people grab him from behind. “I do tend to scream,” he said. And yes, success took more or less until his 40s, but it has been worth the wait. And he finally feels he deserves it.

“My entire career has been a series of pinch-me moments,” he said. “But the bruise is getting too big: I have to just man up and realize I belong here. There’s no time for impostor syndrome; there is no time for insecurity. I belong.”

This article originally appeared in The New York Times.