Wonder illuminates Chris Pratt’s face. Jaw dropped, eyes wide, he presses the button:

“Meet my friends … the Guardians of the Galaxy,” declares his recorded tough-guy voice as an open-mouthed smile spreads across his real face. He presses again: “Don’t mess with my friends.”

“I did this,” he happily says to a publicist on the Disney lot in Burbank. “That’s me! That’s my voice!”

Looking very little like his round-edged “Parks and Recreation” alter ego, Andy Dwyer, the trim and ripped Pratt works the “Try Me” button on the box of his Star-Lord action figure until he has gone through all the messages he recorded for the toy.

Things have changed rapidly for Pratt in the past couple of years. After 14 years in the business, he’s on his first big promotional campaign as a leading man, and it’s for the oddest entry in the Marvel Cinematic Universe so far. He plays Peter Quill/Star-Lord: part hero, part doofus and all leader of the “Guardians of the Galaxy.”

As a boy, Quill is abducted from Earth just after his mother dies; he is raised by space pirates before striking out on his own and discovering a plot between super-beings Ronan and Thanos (remember the first post-credits scene of “Avengers”?) to destroy an entire planet and its billions of inhabitants. Along the way, he meets fellow outsiders Gamora, a beautiful, green-skinned assassin (Zoe Saldaña); revenge-driven, hyper-literal brute Drax the Destroyer (former World Wrestling Entertainment champ David Bautista); genetically and cybernetically modified Rocket Raccoon (voiced by Bradley Cooper); and Groot (voiced by Vin Diesel), a tree of few words.

As wacky as the “Guardians” comic already was, Marvel put the screen version in the hands of idiosyncratic weirdo filmmaker James Gunn (“Slither”). The movie has Gunn’s irreverence smudged all over it. It has a unique sass and saltiness not common to epic franchise installments such as this one, with a reported $170 million budget.

“Marvel is hiring more and more people like James because they’re giving us shots,” Pratt says.

Pratt did have to get into superhero shape (goodbye, doughy Andy) to play Star-Lord, but considering the actor’s off-kilter persona, this most out-there of Marvel movies is a much better fit for him than, say, Captain America or Thor would have been. And sandwiched around this role are Pratt’s Navy SEAL in “Zero Dark Thirty” and his “rugged ex-military man,” according to the studio, for the now-shooting “Jurassic World.”

It’s a career shift he never saw coming.

“I’m a comedian at heart,” he said. “I never thought I was a good enough actor to pretend to be so much different from myself to fit into a leading-man type of role in a big action movie. I typically just put my own spirit into a different vehicle for any role I’ve done. It’s really kind of just been me in the role.”