How this serial killer you’ve never heard of inspired ‘Psycho,’ ‘Texas Chainsaw’ and Season 3 of Ryan Murphy’s hit show ‘Monster’

He’s the ultimate psycho killer.

Serial killer Ed Gein may not be a household name like Ted Bundy or Jeffrey Dahmer, but he looms large in pop culture, inspiring a trio of iconic horror movie killers: Norman Bates in “Psycho,” Buffalo Bill in “The Silence of The Lambs,” and Leatherface in “Texas Chainsaw Massacre.”

Even though the bulk of his crimes were in the 1950s, Gein remains relevant today. Not only are those films classic spooky season staples, but it was also recently announced that Season 3 of Ryan Murphy’s hit Netflix anthology series, “Monster” — which had popular previous seasons about Jeffrey Dahmer and the Menendez brothers — will be about Gein, starring Charlie Hunnam.

Harold Schechter, a true crime historian and author who wrote the definitive book about Gein, “Deviant: The Shocking True Story of Ed Gein, the Original Psycho,” told The Post that up until Alfred Hitchcock’s “Psycho” came out in 1960, all the horror movie monsters were from “other places – Eastern European monsters like Dracula and Frankenstein or the Wolfman. Or, monsters from outer space. Or, monsters that arose out of the Japanese seas, like Godzilla.”

But, he said, Norman Bates was “the first really all-American monster.”

He added, “and it really transformed horror films after that. So, Gein is kind of a seminal figure in the history of horror” because he inspired “Psycho,” which, in turn, “created the modern slasher movie.”

Gein, who lived in Wisconsin, was born in 1906 and was known as The Butcher of Plainfield. Despite inspiring several fictional serial killers, he only had two confirmed murders (with more suspected). He’s notorious not for being prolific but for the bizarre and horrifically disturbing nature of his crimes.

Schechter, who has written over a dozen books about serial killers and mass murderers, explained, “His whole thing was trying to reconstitute his mother by digging up the bodies of these middle aged women in the communities around him, bringing them back to his farmhouse, making various household objects out of their body parts, and a skin suit that he would wear and pretend he was his own mother.”

After Gein’s crimes came to light in 1957, he pleaded not guilty by reason of insanity. He spent the rest of his life in Wisconsin mental institutions until he died from lung cancer in 1984 at age 77.

While researching for his book “Deviant,” which was first published in 1989, Schechter interviewed Gein’s former neighbors and acquaintances.

“He was just basically regarded as – not quite the village idiot, but this slightly goofy lonely guy. He would babysit for his neighbors,” he said.

“They thought of him as a local weirdo, but he seemed harmless enough…Obviously, no one could possibly imagine what was actually going on inside his farmhouse, because it’s pretty unimaginable.”

Although the average person has watched “Psycho,” “The Silence of the Lambs” or “Texas Chainsaw Massacre,” unless they’re a true crime aficionado, Gein isn’t a famous name in the same way that serial killers like Bundy or Dahmer are.

Schechter attributes that to the fact Bundy and Dahmer were active more recently, while Gein’s era dates further back.

Schechter, a retired Queens College professor who used to teach a class on myth and folklore, said that Gein cast a long shadow in pop culture because “there are certain stories that keep being repeated in different forms. Something in the human imagination seems to require these different stories. Every now and then, something will happen in the real world that seems to be the real-life incarnation of some ancient folklore. There are elements of the Gein story that are like that.”

He cited the Hansel and Gretel fairytale, the Boo Radley character from “To Kill a Mockingbird” and even a story from his own childhood in the Bronx about “some old lady who lived on the sixth floor” as examples of the type of oft-told tale about, “some creepy person who lives in some remote house… The Gein story was like one of those fairytales come to life.”

The retired professor continued,“There’s something very resonant about that story. And the details of it lend themselves to being retold – as is the case of all folktales.”

Each different form of retelling reflects the era it’s released in, he said.

For instance, Schechter said that “Psycho,” which came out right after the 1950s, reflects a mentality “when there was this hidden dirty quality to sex. The movie opens with this camera going into this hotel bedroom where these two lovers are having this tryst. It’s all about voyeurism, and the things that reflect this kind of sexual duplicity of the ‘50s.”

Meanwhile, he thinks that 1974’s “Texas Chainsaw Massacre” had to do with the Vietnam War era.

“It uses the Gein myth and turns it into this story about how America has turned into this machine that butchers its young people,” he said.

He also believes that 1991’s “‘The Silence of the Lambs” has something to do “with cosmetic surgery,” explaining “the obsession about altering your body. Buffalo Bill wants to become this beautiful woman.”

As gruesome as it is, Gein’s story has a “kind of mythic archetypal quality that makes it very susceptible to being told and retold in these different forms,” he added.

Nevertheless, Schechter has some reservations about the next incarnation of the story, when Season 3 of Ryan Murphy’s “Monster” will premiere (at an unannounced date on Netflix). Since Gein is more obscure than Bundy or Dahmer, fewer books about him exist.

“I hadn’t been approached in any way. And my book – in all modesty – is the definitive Gein book,” he said. “Certain alarm bells went off, like, ‘How can they make this without at least consulting my book?'”