The crazed killer who gunned down five people, including a young girl, in the U.K.’s deadliest mass shooting in more than a decade said he was an American-born, virgin "incel" — and compared himself to "The Terminator," according to reports.

Jake Davison, a 22-year-old apparent fan of the New York Giants football team, was identified Friday as the gun-obsessed man behind Thursday’s bloodbath in Plymouth that a local MP decried as "unspeakably awful."

He is believed to have first shot dead his mother at their family home, before running out and killing a 5-year-old girl, her dad and two others before turning the gun on himself, according to officials.

Forensic officers walk in Biddick Drive in the Keyham area of Plymouth, England on Friday, where six people were killed in a shooting incident.

Forensic officers walk in Biddick Drive in the Keyham area of Plymouth, England on Friday, where six people were killed in a shooting incident. (Ben Birchall/PA via AP)

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Police said they were examining his hard drives and online activity, which included YouTube channel in which he regularly whined about being a "fat as f---" virgin who has never kissed a girl, according to numerous U.K. reports.

Saying he was "getting uglier" and "defeated by life," he related to Incels, the "involuntary celibates" behind a series of devastating mass murders in the U.S. and Canada.

His social media — since taken down — showed he was obsessed with American gun culture, and even claimed to have been born in Arizona, The Sun noted, although that has yet to be verified.

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Davison wore a Giants shirt in his last YouTube rant late last month in which he compared himself to the killing machine played by Arnold Schwarzenegger in "The Terminator."

"The whole premise of the Terminator movies is that you know everything is rigged against you, there’s no hope for humanity, you know, we’re on the brink of extinction, these machines are unstoppable killing machines that can’t be beaten, can’t be outsmarted, but yet humanity still tries to fight to the end," he said, according to The Times of London.

"I’m a Terminator."

Using the name Professor Waffle, Davidson’s YouTube also showed him bodybuilding and admitting to taking steroids and dreamed of "cocaine fuelled sex," the U.K. paper noted.

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His slaughter was the worst mass shooting in the U.K. since 2010, when taxi driver Derrick Bird shot dead 12 people and injured 11 others before committing suicide in Copeland, Cumbria.

Davidson, meanwhile, is believed to have used a pump-action shotgun that he was licensed to own, police said.

Plymouth Sutton and Devonport MP Luke Pollard called it "unspeakably awful" and said he was "utterly devastated" to learn one of those killed was a child.

Prime Minister Boris Johnson said that his "thoughts are with the friends and family of those who lost their lives and with all those affected by the tragic incident in Plymouth last night."

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Incels first became prominent in 2014 after Elliott Rodger, 22, killed himself after gunning down six people, including two women, outside a sorority house near Santa Barbara, California.

Rodger left behind a manifesto that has been a rallying point for online "incels" — short for "involuntarily celibate" — who justify violence against women as revenge for being rejected as sexual partners.

This story first appeared in the New York Post.