When Hurricane Ida struck New York last month, an incredible, terrifying scene occurred in the subway station at 28th and Seventh Avenue in Midtown Manhattan. Water began gushing from under the platform in a violent, torrid geyser, turning the subway into a Universal ride.

One rider captured the moment on a smartphone and, within an hour, the video was posted to the Instagram account SubwayCreatures, where it racked up hundreds of thousands of views. TV stations across the globe picked up the 20-second clip, which became a defining image of the deadly storm, if not the precarity of urban life in a warming world.

That the clip first appeared on SubwayCreatures was fitting. The account, which has been around since 2013, aims to provide a voyeuristic look at the New York City Transit system, but it has also become a clearinghouse of breaking news and viral videos.

Like any reality show, SubwayCreatures focuses on the bizarre, the sensational, the comic and, occasionally and for good measure, the surprisingly poignant. It is not interested in your humdrum daily commute, but rather the crazy incident that snaps you from your dead-eyed stare. It uses the great equalizer — the facet of city life with which every New Yorker but the wealthiest must engage — to channel and broadcast our collective id.

Recent posts include a video of a rat on the tracks hauling off a crab; a photo of a seated male rider casually looking at his phone while clutching a blowup sex doll; and a guy wearing face paint like the “Batman” villain Joker and juggling a butterfly knife.

Daring passenger-on-the-tracks rescues provide the occasional high-stakes drama. Buskers appear regularly. So do animals, whether a raft of ducks or a man in a body suit with fabric plumage.

“Whenever you think you saw the wildest thing on that page, there’s always something the next day that makes you forget,” said Shannan Ferry, an anchor and reporter for NY1 who counts herself among the account’s 2.4 million followers. “The New York City subway is the gift that keeps on giving.”

SubwayCreatures gets virtually all of its content from fellow riders, who see something striking, take out their smartphones (discreetly, one hopes) and send the photo or video to the account’s creator, listed as @rickmcguire13.

It will shock no one to learn that @rickmcguire13, whose real name is Rick McGuire, is a veteran TV producer who lives in Hell’s Kitchen and specializes in viral videos. He once worked on a clip show called “truTV Presents: World’s Dumbest …” and spent several years freelancing for MTV and other networks.

SubwayCreatures began as a hobby website, with Mr. McGuire posting videos that he took, and aggregating weird images he scoured from the web. But the Instagram account has since grown so popular — and lucrative — that it has become his full-time job.

Mr. McGuire makes money by licensing the videos to media outlets and clip shows such as MTV’s “Ridiculousness.” He also runs sponsored posts: recent examples include a video of the Irish singer-songwriter Hozier performing in the subway for Columbia Records, and videos of people moving large, weird items on the subway paid for by Openigloo, a landlord review site.

Mr. McGuire, who receives dozens of submissions each day for SubwayCreatures and two other Instagram accounts he manages, WhatIsNewYork and WhatNewYorkEats, said his main challenge is seeing the human comedy with fresh eyes.

“There’s a part of me that’s completely desensitized,” said Mr. McGuire, sitting on a recent evening in Union Square Park, where he enjoys people watching. “You really see the worst of New Yorkers. I have to think, ‘What would a normal person think of this?’”

The rat and the crab, however, was a no-brainer. “People eat these videos up,” Mr. McGuire said. “It was a ‘Finding Nemo’ situation — the beginning, or the end, of a Disney movie.”

Mr. McGuire, who is 37, said he avoids posting conflicts — the camera always turns on midway through the argument, making it difficult to judge what transpired. He also stays clear of politics.

What about nudity and other lewd behavior?

“I get that at least once a day,” Mr. McGuire said. Earlier that day, in fact, he had posted a video of a woman rubbing a man’s nipple on a packed train car. “I was worried” that it went too far, he said. “But I thought it was so out there and wild.”

When people submit videos to SubwayCreatures, they must agree to sign away their copyrights. If Mr. McGuire licenses someone’s video, however, he cuts them in on the deal. “It incentivizes people to continue sending videos in,” he said.

On the day that Ida hit, Mr. McGuire anticipated a busy night and set up a command center in his apartment, where he monitored several weather-tracking apps. He told his girlfriend, “You gotta just let me go.”

Mr. McGuire received more than 800 videos, he said, and was fielding requests from TV producers in Japan, Switzerland and Germany. “I was up to 3 or 4 a.m.,” he said. “In my world, you have to be first. You don’t want to be the second to post a video.”

Mr. McGuire has come to think of himself “almost like a stringer for the media,” especially during events that affect the subway like storms.

Still, he said, his favorite videos are less dramatic, what he called “New York moments.” Like when someone’s luggage wheel got stuck in the closing doors, and the other passengers all got up to help, mostly to get the train moving again.

Mr. McGuire likes to post real acts of kindness, too, but rarely receives them. “No one is recording for the good things,” he said.