A homeless ex-con charged with shoving an NYU student and a Big Apple tourist in separate unprovoked attacks was even more unhinged in front of a Manhattan judge.

James Rizzo, 45, rolled his eyes, snarled, growled, and at times appeared to go into a zombie-like trance Wednesday in front of Judge Cori Weston, as he appeared in court on a slew of charges.

“Not guilty!” Rizzo yelled in a gravely tone when asked how he pled to the two indictments.

The violent vagrant — who was ordered held with out bail — made headlines when he allegedly randomly attacked NYU student Amelia Lewis, 20, as she walked to class on Broadway around 9:30 a.m. on Dec. 2.

Shocking video footage of the incident shows Lewis, an aspiring model, walking down the street when the goon comes up behind, smacks her butt and knocks her to the ground before walking off.

“As I’m walking, like with my headphones on listening to music, I feel something slap me so hard, like literally on my ass,” Lewis, 20, said in a tearful TikTok post following the assault. 

“And I was like, ‘Oh my God, oh that hurts so bad!’ I thought it was like one of my friends. I was gonna turn around and be like, ‘Oh, that hurt so bad, why did you do that?’

“But when I turned around, I saw this old white guy. And like right when I turned around, he grabs my f—ing hair like this and like yanks me and like threw me to the ground. My headphones went f–ing flying,” Lewis sobbed. 

“And I was like on the ground and I saw him just bolt away down Waverly. And I was like, ‘Holy s–t? What the f–k just happened?’”

Authorities said that wasn’t the only incident Rizzo is charged in — he allegedly shoved a 68-year-old woman as she walked on Fifth Avenue near West 47th Street around 8:45 p.m. in an unprovoked Thanksgiving Day attack.

“I was about a step or two behind her and out of nowhere this guy appears in my face and starts talking crazy talk, like, ‘Our whole society is a f—ing joke, right?’” Jana Dianne Brazell, a retired college professor from Texas who was visiting her sister-in-law in the Big Apple told The Post.

“He stepped back,” she said. “I thought, thank goodness he’s moving away. The next thing I know, I’m flying in the air and I hit this glass wall at the side of a building. I just slid down.

“This whole encounter with him was like six seconds,” she said. “It was so fast.”

Rizzo has 16 prior busts, including for sexual abuse and forcible touching.

He was released from state prison in September after being sentenced to two years behind bars on a persistent sexual abuse conviction, online correction records show.

In court Wednesday, he wore a brown jacket, leg and wrist shackles and a long, greasy pony tail.

Manhattan Assistant District Attorney Kailey Wilk told the judge that Rizzo faces up to seven years in prison on the most serious charge — and still faces additional burglary and assault charges.