Brie Larson's 'Emotional' Reaction to Putting on Her 'Captain Marvel' Suit for the First Time (Exclusive)

ET was first on the set of Marvel's upcoming 'Captain Marvel' to talk suits and stuntwork with Larson and Samuel L. Jackson.

"What's crazy is these movies are so secretive, you don't get to share that," the newest recruit to the Marvel Cinematic Universe, Brie Larson, told ET of the moment she donned her super suit for the first time. "Now I can share it! Now we can be like, 'Oh my God!'"

Following the premiere of Captain Marvel's first action-packed trailer this week -- which provided a first glimpse of the suit in question -- fans are saying just that. ET was on the set of Marvel's first female-fronted movie, and we witnessed Larson's red-and-blue suit in the flesh during our interview aboard one of the film's spaceship. (And that's about all we can say about the ship... for now.)

"I was trying different pieces on," Larson told ET's Nischelle Turner of the nearly year-long process of the suit being built. "Then when I finally put it all on together, I was just staring at myself in the mirror and I did get emotional...The first time I put it on I was like, 'I'm like a Disneyland character! This is crazy!'"

Marvel Studios

Beyond donning the suit, in order to play Air Force pilot Carol Danvers-turned-alien superhero Captain Marvel, the Oscar-winner committed to months of physical preparation -- check out any of the insane workout videos she shared on Instagram -- with the goal of doing many of her own stunts.

"I was an introvert with asthma before this movie, so I was like, I got to get it together for this! I carved out nine months to train and kind of retool everything," Larson said. That retooling is at work in this behind the scenes footage that sees Larson jumping onto the roof of a train and battling with Jude Law.

"Honestly, it smells so bad I'm not sure I want it," Larson laughed of whether she will steal her suit after the movie wraps. "I'll take a fresh one though!"

The highly-anticipated Marvel film also stars Law as Captain Marvel's alien mentor, Lashana Lynch as Carol's best friend and fellow Air Force pilot, Maria Rambeau and Samuel L. Jackson, who reprises his role as S.H.I.E.L.D. agent Nick Fury, who ends up getting a new look of his own.

"These dots are my Botox. I'll look younger by the time the movie is out," Jackson deadpanned regarding the special effects dots used to map his face before CGI could shave off a couple decades. In Captain Marvel, he will also have a full head of hair, but no eyepatch. (Although, he was sporting a very interesting injury on this particular day of filming.)

"I did a couple movies in the '90s that they can go back and use that face," Jackson added.

Captain Marvel will soar into theaters on March 8, 2019.