Phase 3 of the Marvel Cinematic Universe is officially under way with last weekend's debut of Captain America: Civil War. Fans turned out in droves for this superhero adventure, to the tune of $179.1 million in its opening weekend. The movie not only showed the entire MCU being torn apart by the Sokovia Accords, but it also introduced Spider-Man (Tom Holland) and Black Panther (Chadwick Boseman). Still, the biggest moment, literally, in the movie came from one of the MCU's other newcomers, which we have new details about below. If you haven't seen Marvel's Civil War yet, there will be massive SPOILERS below, so read on at your own risk.

When Captain America: Civil War started shooting last May, the studio unveiled an official cast list, which revealed that Ant-Man star Paul Rudd would reprise his role as Scott Lang. It didn't take long for rumors to spread that this movie may feature our first look at Giant Man, the polar opposite of the miniscule Ant-Man, who surfaced during the epic airport battle between Team Cap and Team Iron Man. io9 caught up with producer and Marvel Studios President Kevin Feige, who revealed they thought the time was right to showcase Giant Man in this movie, and not in the upcoming sequel Ant-Man and the Wasp, which tied into Spidey's introduction as well.

"It was just a great idea to turn the tide of the battle in a huge, shocking, unexpected way. We have a lot of ideas for Ant-Man 2, none of which are contingent upon revealing Giant Man, so we thought this would be the fun, unbelievable unexpected way to do that. We knew if we got Spidey we could have him do the AT-AT thing."

As it turns out, though, Kevin Feige and the studio weren't convinced about introducing Giant Man right away. Captain America: Civil War writers Christopher Markus and Stephen McFeely teased that there was some "pushback" about Ant-Man transforming into Giant-Man early on, and directors Anthony Russo and Joe Russo really had to fight for his inclusion. Here's what Stephen McFeely had to say.

"The brothers [directors Joe and Anthony Russo] had to fight for it. They had to go to the studio and say, 'No it's not silly, it's cool.' It's a comic book movie! In the grounded Winter Soldier, it's Three Days of the Condor except in the middle there's a talking robot that tells you HYDRA has been there the whole time. And a lot of people went, 'That's a little much.' No, it's a comic book movie! That's okay. Same thing here, except it's Giant-Man."

Kevin Feige has revealed in the past that the MCU's history of cutting off people's hands is an homage to the Star Wars films. In Captain America: Civil War, they included a more direct reference, when Spider-Man suggests they use the same strategy Luke Skywalker (Mark Hamill) uses to take down the AT-AT in Empire Strikes Back, to bring down Giant Man. Stephen McFeely added that the directors also fought for that scene as well, although the writers aren't big fans of referencing other movies.

"The brothers really wanted to put it in there. We get a little queasy about referencing other movies. They don't, and they were right."

Speaking of Giant Man, Marvel has also released the first official photo of this massive superhero, which you can check out below. Marvel has already set a July 6, 2018 release date for Ant-Man and the Wasp, but it remains to be seen if the enormous Giant Man will return in the sequel. Star Paul Rudd is also co-writing the script alongside Ant-Man writers Andrew Barrer, Gabriel Ferrari and Adam McKay, with Peyton Reed returning to direct. While we wait for more on this sequel, check out the first official photo of Giant Man below.