How Fast X "Randomly" Landed John Cena a Merman Role in Greta Gerwig's Barbie Movie

What do Fast X and Barbie have in common? Don't be so quick to answer "nothing." According to John Cena, the two blockbuster films (both of which are releasing this summer) "share a lot of parallels," especially where their stacked casts are concerned. The projects also happened to shoot across the street from each other, which led to "an accidental run-in" between Cena and Margot Robbie.

"We randomly ran into each other as friends," the former said during a guest appearance on Today this week. "And [she said] 'Why don't you do Barbie? I said, 'I've been trying.' Margot makes a lot of the decisions for that and I said, 'I'll do whatever you need.'"

Long story short, that's how former WWE superstar John Cena landed a cameo as a merman in the Greta Gerwig production. "It's surreal," he added. "Honestly, I think a lot of people are gonna have fun watching this. I think it's gonna take a lot of people by surprise. [It's] a very interesting take on everything. But I was super lucky and it's tremendously surreal."

Speaking at CinemaCon last month (via The Hollywood Reporter), Robbie touched on the regular visits to the Barbie set from the Fast & Furious crew members. "You’ve never seen so many grown men find excuses to come to set. It was like a dopamine hit. You were instantly happy, and we felt that every day."

RELATED: Fast X Expected to Drive Circles Around Box Office with Nearly $300 Million Debut

In keeping with Fast Saga tradition, Cena's returning Fast X character — Jakob (or "cool Uncle Jakob," as Cena describes him) — has gone from antagonist to ally. Dom's little brother is now a proud and card-carrying member of the extended Toretto pit crew. Family, as you probably know, is everything.

"No one ever dies, they bring back all the characters," Cena continued. "No one's ever bad. They turn all the bad guys into good guys. So it's kind of like a right of passage to get your own car, got that. To be a bad guy and [then] be a good guy, got that. And now, I get to be a cool uncle. Jakob Toretto is responsible for getting Little B, Little Brian Toretto, to safety while the rest of the family is in peril — held up by a wonderful performance by Jason Momoa."

Just don't expect Dante Reyes to be switching sides by the end. The ostentatious bad boy of Brazil "has no intentions of turning good," Cena teased, going on to add that Momoa "steals the show in this role." That's been the general consensus among those audience members who have been lucky enough to check out early screenings of the film since it premiered at the Colosseum in Rome last Friday.

Fast X hits the big screen this Friday, May 19. Need tickets? Click here! Barbie, meanwhile, arrives in theaters everywhere Friday, July 21 — the same day as Christopher Nolan's Oppenheimer.

Relive a small portion of the Fast Saga with Furious 7 — now streaming now on Peacock. If you want to catch up on the full story, however, click right here for our nifty guide on where to stream the first nine installments (plus Hobbs & Shaw).