It’s a jungle down there.

A mystery man has been strutting the streets of the Upper West Side — and the subways below — with a 6-foot snake coiled around his neck.

One resident was rattled by the transit-riding reptile.

“This man walked right into the subway station at West 96th and Broadway and down to the trains with this huge snake wrapped around his neck!” Michelle Kucsma, 65, posted on the community app Next Door.

“I told both the clerk and two police officers at the station but they were not concerned at all,” she wrote.

“The police told me it’s not illegal to bring a snake on the train and surmised that it might be an emotional support animal.

“I said, ‘I would need a support animal to deal with that support animal!'”

The officers claimed the snake was “just like a cat or a dog,” she recalled. “They also said you could bring a rat on if you wanted.”

Kucsma described the creepy Thursday encounter to The Post.

“I was shaking. It was huge. It was as wide as my hand open, and went way down below his waist. He was very calm walking around.”

Sarcastic cops aside, many types of snakes — including vipers, cobras, pythons and anacondas — are illegal in the five boroughs.

Kucsma, a Louisiana native who has lived in the Big Apple for 30 years and is retired from the state court system, wasn’t alone in her fear.

Sarah Hayden also posted on the app about the snake charmer, saying she was leaving the “Barbie” movie at the AMC Empire 25 on West 42nd Street with her husband and 11-year-old daughter when she walked by a man with a “huge” snake in Times Square.

“I brushed past and my husband said, ‘That snake just about bit you!’ ” the Murray Hill resident who hails from Ireland told The Post.

“I wasn’t too thrilled,” she said of the Aug. 26 sighting. “I thought there was some restriction on live animals.”

She believes the snake handler she saw is the same as the one Kucsma photographed.

“Maybe St. Patrick can get rid of the snakes — and the rats while he’s at it!”

Ryan Shannon, 42, who runs The Snake Pit NYC reptile store in Queens believes the unidentified pedestrian is wearing a boa. “You see dudes walking around with them on the Coney Island Boardwalk and in Times Square,” he said.

The NYPD referred The Post to the department’s patrol guide, which specified that emotional support animals are allowed, animals on transit must be “enclosed in a container and carried in a manner which would not annoy other passengers.”