Watch: John Cena loses 'Peacemaker' helmet to Jimmy Fallon ahead of HBO Max premiere

John Cena was forced to cede his shiny Peacemaker helmet to Jimmy Fallon on last night's episode of The Tonight Show after the two played a number of "Make it Last" challenges. Had Fallon lost, he would have been forced to frost the tips of his hair. Luckily, the talk show host didn't have to go full boy band and was able to don Cena's gleaming headgear for the start of their interview together.

"John, this is heavy, this is expensive, but I'm keeping this," he said.

"I'm a man of my word," replied the actor. "And technically, I don't own it, but it's yours." Cena then added that he'd probably get in trouble for it: "I can't even go anywhere with the costume. They have a person who travels with the costume and the helmet comes in its own thing and the person travels with the helmet. They're like, 'Here's the costume and here's the helmet — take care of it...'"

Nevertheless, Cena was truly a man of his word, appearing on Good Morning America Tuesday without his helmet.

Written by James Gunn, Peacemaker (premiering on HBO Max this week) follows the titular antihero in the wake of The Suicide Squad. When a new threat to American security rears its ugly head, the peace-obsessed frat boy with an inferiority complex is brought into the fold of a new team comprised of Vigilante (Freddie Stroma), Harcourt (Jennifer Holland), Economos (Steve Agee), and Murn (Chukwudi Iwuji).

"He's such an unbelievably gifted storyteller," Cena said of Gunn, going on to recount how the show first came together. "If you saw The Suicide Squad, Peacemaker's future is very questionable and he called me up in the middle of lockdown. He's like, 'Hey, man, I want to do a series on Peacemaker.' I said, 'Hey, man...isn't Peacemaker dead?' And he was like, 'No, no — I got it taken care of.' I said, 'Ok, I'm in. No problem.' I just let him go to work and he wrote eight episodes in eight weeks and then we filmed very shortly after that."

The actor explained that the overall theme of the spinoff "is about wanting to be a superhero. Peacemaker is a guy who wears a uniform and has a set of skills and some helmets that can do some pretty incredible things. Peacemaker is an antihero because true acts of heroism are virtuous and Peacemaker is heavily flawed. He's a human being like all of us and he wants so badly to be accepted as his perception of himself, which is a superhero. And that's kind of where the humor of the show comes [from]. He's way out of touch with reality, he's got his own lens on life, and in doing so, offends pretty much everybody."

Peacemaker lands at HBO Max on Thursday, Jan. 13.