Damontre Moore smiles and his eyes widen when you ask him to tell the good people of Cleveland what they are about to witness when the Johnny Manziel Era begins Sunday against the Bengals.

“Getcha popcorn ready, there’s about to be a show — Johnny Football, he earned that name for a reason, so sit back and let him do what he do,” Moore told The Post.

The second-year Giants defensive end got to witness firsthand Johnny Football magic and mania as his Texas A&M teammate.

“At one point in time, everybody’s gonna change the league, you know, RG3, Russell Wilson, and Johnny Manziel now,” Moore said. “I feel like you gotta build your team around him just how they built the scheme around RG3 and they built their team around Andrew Luck. I feel like that’s the same thing with Johnny, it’s just that he has different qualities, but you can build around him. He can throw, he can run, and he has a competitive edge towards him, and he has one of the biggest hearts, and if you got all those combinations, it’s amazing. It’s gonna be something exciting to watch.”

Moore saw plenty of examples of Johnny Football’s heart — in practice and on game day.

“I’ll never forget, my ‘older brother’ Tony Jerod-Eddie, it was Johnny’s redshirt freshman year, he kinda controlled the tempo of practice,” Moore recalled. “We could never hit the quarterback, but Johnny used to always scramble and do everything that he’s doing now, and Coach was yelling at us, and it was like, ‘You letting the scout team quarterback run on y’all?’

“I believe we were preparing for the Mizzou game if I’m not mistaken, James Franklin, we were preparing for him. It was like, ‘If Johnny can do this in scout team quarterback, what is a Division I starting quarterback gonna do to us?’ And Tony was like, ‘Don’t let him embarrass no more, go out here and hit him.’ And when we hit him, we hit him a couple of times, the coach was like, ‘Y’all need to stop hitting the quarterback,’ and Johnny looked over to the coach and yelled at him. He said: ‘Naw, let ’em hit me, I like it!’

“And he came back out there, and he did a crazy spin move, ran all the way to one side of the field, ran to the other side, then threw a deep ball pass to Mike Evans. Mike Evans jumped up on our starting cornerback and grabbed it one hand, and that’s when we were just like, ‘We know that boy’s gonna be special.'”

Moore was hard-pressed to think of one special Johnny Football example.

“He puts on a coaching clinic,” Moore said. “I think the one thing that people don’t realize about Johnny is they say he looks to run and scramble to get yardage, but Johnny’s looking to run to throw a deep pass. He’s not scrambling to get yards, he’s scrambling to get his receivers open. That’s the one thing you don’t realize, and so when you try to be too aggressive and run up on him, he’s looking down the field the whole time. I mean, you can’t just really just name one play.

“I think one of my most favorite plays from him was in the [Alabama] game last year. He scrambled like back and forth, shrugged off two tackles, and threw like a 40-something yard pass to Edward Pope, and it was just a jump ball and Pope made a tremendous catch, but for him to keep the play alive that long and kinda keep calm and focused and still be looking down the field, I mean, that showed me right then and there he’s gotten older and better like versus just going straight downfield.”

Marvin Lewis may believe the 5-foot-11 Johnny Football is too short. Not Moore.

“The Seahawks won the Super Bowl with Russell Wilson, and he’s an inch-and-a-half taller than him, so if he can do it, anybody else can do it,” Moore said.

The off-the-field partying and controversies, the Johnny Playboy persona, all overblown in Moore’s eyes.

“Everybody has their own opinion and they’re entitled to it, but it doesn’t mean that they’re always right,” Moore said. “What sells papers is that playboy look, so that’s what they sell him as. But Johnny’s just a typical young guy. All the stuff they were reporting about him, he was 18, 19, 20 at the time — what do most 18-, 19-, 20-year-olds do, especially they’re not in his situation. You think all of the famous pop star celebrities, rappers, singers and all that, that’s around his age, they’re in the media all the time, so c’mon now. I feel like you can’t hold them against him. He’s being a young kid.”

But now, as the starting quarterback of the Cleveland Browns, Johnny needs to be All Football.

So he can again elevate the play of those around him — on both sides of the ball.

“We used to sit there on defense and be like, ‘What kind of great play is he gonna make?’ And when he makes a great play, that motivates us to be out here like, ‘All right, we gotta get him the ball back, so he can go make another great play and we can keep watching him,'” Moore said.

Then Moore compared Manziel to his rookie Giants teammate Odell Beckham Jr.

“Just like ODB, you know he’s gonna make a great catch, we just gotta worry about holding ourself down so we can give him time,” Moore said. “It’s not what kind of play he’s gonna make, it’s when is he gonna make that play? It’s only a matter of time.”

Doubt Johnny Football at your own peril.

“Johnny is a true competitor,” Moore said, “and one of his biggest attributes that I really liked is he’s always been an underdog. People have always doubted him as to, ‘Will he be able to compete at the next level?,’ and he always proves them wrong.”