The moniker is given to the former Heisman Trophy winner in a new commercial for Snickers, which shows him as an aerobics instructor.
Wearing spandex and a headband, Manziel is teaching a class of women all of his moves until a confused man in a Browns uniform walks in and hands him the candy bar.
Once Manziel takes a bite, he is immediately transformed into himself again.
"It was a thrill to star in my own 'You're Not You When You're Hungry' commercial because it allowed me some funny version of myself that I might become when I'm hungry," Manziel said in a statement. "I hope people have as much fun watching the ad as we did filming it."
Manziel admitted after the Browns' 33-13 preseason win Thursday night that he was "a little out of my comfort zone at the beginning."
"It was no Joe Pesci," he said.
He said that when the ideas were first presented to him, "at first I wanted to get back on the plane and come back home."
"I went through with it," he said. "It worked really well."
Aside from Snickers, Manziel has national deals with Nike, McDonald's, Nissan and Panini Authentic, billed as the world's largest sports and entertainment collectibles company. Despite being the named the Browns' backup to start the season, he has the best-selling jersey in the NFL this fiscal year (since April 1).
ESPN.com's Pat McManamon contributed to this report.