A raving lunatic beheaded two pigeons in Bryant Park, proclaimed he was a “vampire” — and guzzled their blood in front of a horrified crowd, witnesses told The Post.

“He was holding up the pigeons and drinking their blood, letting the blood drip down his shirt,” recalled shocked onlooker Dominic D.

“He did it twice,” the 32-year-old said. “He was covered in blood. He said he was a vampire. It was pretty disgusting.”

Witnesses told The Post that the man threw one of the dead bird heads and splattered blood all over the shirt of a person who was eating lunch. He then calmly waited for cops to arrive.

“He was very calm when the police came,” explained Clarissa Plair, a 26-year-old Theology student who spends a lot of time in Bryant Park and has seen the pigeon perp before.

“He’s always here, yelling at people on the street,” she said. “He was telling [police] he’s a vampire.”

Authorities took a man into custody about 15 minutes later and transported him to St. Luke’s-Roosevelt Hospital for a pysch evaluation, according to officials.

Photos and video posted on Twitter showed the bloody aftermath, with several pigeons swooping in to mourn their fallen bird brethren.

While the man behind the fowl fatalities is known to sit in the Bryant Park fountain drinking beer, witnesses said he’s never gone after any of his feathered friends before.

“He’s here every day, but I’ve never seen him do this before,” said Dominic.