If you haven't seen Captain Marvel yet, be prepared for some spoilers up ahead.
So as we know from watching the newly-premiered MCU film, there was absolutely no mention of Brie Larson’s character’s superhero name, as she was just called Carol Danvers. Even though the movie is explicitly called Captain Marvel, there is no utterance of the name in the movie at all. So of course, fans have started creating theories about when and how we will hear the first mention.
Reddit user swayde620 thinks that we should expect the name to be officially dropped in Avengers: Endgame, out this April. The theory explains that the transformation from Carol Danvers to Captain Marvel will likely happen sort of similarly to how it did in the comics, which might take place after Captain America sacrifices himself to restore everything to the way it was. The theorists claims Carol will take “Captain” out of Captain America, and “Marvel” from her mentor Mar-Vell, played by Annette Bening.
While that’s not exactly how it went in the comics, Captain America did convince her to take Mar-vell’s name, who had passed away.
The theorist also brings up an important point of how inconsistent the usage of names are in the MCU. “Tony may refer to Steve as ‘Cap’ while Natasha calls him Steve. Everyone refers to Hawkeye as Clint and of course Thor and Vision dont have codenames,” they write. In this case, it doesn’t really matter when Carol is called Captain Marvel, we just want to find out how the name comes about.
[h/t: Comicbook.com]