Rob Gronkowski's Shredded Shots To Kick Off His 35th Bday!

While Rob Gronkowski may have made headlines with his frat boy funny stuff at the Tom Brady Roast on Netflix ... there is nothing funny about this birthday boys shirtless shots.

The former NFL tight end has repeatedly hit his social media with some hot selfies and the now 35-year-old athlete and notorious partier is putting his A-list abs on full display.

Gronk's Greek physique is no doubt an age anomaly ... and the only real way to verify his age is to chop his down and count the (Super Bowl) rings!