Here’s how each member of the Avengers got their superhero names in the Marvel Cinematic Universe. Robert Downey Jr. and Jon Favreau’s Iron Man established the MCU’s indifference when it comes to secret identities, but that doesn’t mean that the universe’s characters roam around using their real names.

The MCU has grown exponentially over the years, with each movie bringing in more superheroes to join the franchise. While they differ in skillsets, origins, and adventures, Marvel Studios has remained committed to crafting key players that are grounded and relatable. This way, the public is invested not just in their superhero adventures, but also in their personal character arcs.

Related: Endgame: Who Every Avenger Would Have Seen In The Soul World

The main focus has been on the heroes’ professional adventures, especially when it comes to ensemble movies. Given that, here are all the characters who have become an official Avenger during the Infinity Saga and how they got their respective superhero codenames.

Tony Stark’s (Downey) final duel with Obadiah Stane/Iron Monger (Jeff Bridges) at Stark Industries in Iron Man made the headlines, with the media and the public curious as to what really happened. As James “Rhodey” Rhodes (Terrence Howard) and SHIELD representative, Phil Coulson (Clark Gregg) do damage control, Tony gets ready to face the press to personally refute rumors that he’s the one wearing the armor. Just before Coulson hands him his spiel, he reads the newspaper dubbing him “Iron Man.” While he argues it’s not an accurate description, he likes the moniker, resulting in him publicly claiming the nickname in the iconic final shot of the movie.

For most of his stint in the MCU, Bruce Banner (Mark Ruffalo) has tried to exist separately from the Hulk, so it’s not a surprise that he barely mentioned his green alter-ego in his early years in the franchise. Typically, he would only refer to him as the “other guy.” In The Avengers, he shakily called his other persona “Hulk” while talking to Tony Stark about a potential silver lining in his predicament. Since then, more and more people have started calling the beastly creature the Hulk. Years later in Thor: Ragnarok, Banner’s alter ego was introduced in Sakaar’s Battle of the Champions by the Grandmaster (Jeff Goldblum) as the “Incredible [Hulk].”

Natasha Romanoff’s (Scarlett Johansson) full backstory as a Russian spy has yet to be revealed, but as an alumnus of the Red Room a.k.a. Black Widow Program, she assumed the moniker like everyone else who was subjected to the same training. Chronologically in the MCU, however, she was first called “Black Widow” by Russian Colonel-General Georgi Luchkov (Jerzy Skolimowski), albeit in his mother-tongue, during her first scene in The Avengers. Not long after that, footage of her and Clint Barton/Hawkeye (Jeremy Renner) during the mysterious Budapest encounter reiterates her code name as Black Widow.

Related: The MCU’s Black Widow Is More Dangerous Than You Think

As one of the few MCU heroes who do not have a codename, Thor (Chris Hemsworth) simply goes by his name, “Thor.” In the comic books he had a human name, Donald Blake, who was the host body for the Mighty Thor. But since Marvel Studios isn’t big on secret identities, they opted to simply call the character Thor (though there is a nod to his human alter ego when he uses a fake ID with the name Donald Blake). The Asgardian Prince/King was named after the Norse god of thunder and lightning.

Unable to be drafted into the military due to his underweight body and many health problems, Steve Rogers (Chris Evans) joined the government-backed Project: Rebirth/Super Soldier Program in the hopes of being granted the Super Soldier serum. While he was chosen the privilege in Captain America: The First Avenger, Steve was initially only used as a propaganda tool for the U.S. government instead of being deployed in the frontlines. During his stint as a mascot touring to raise funds for the country’s war efforts, Steve was given the nickname “Captain America” to appeal to citizens’ patriotic nature. The nickname stuck even when he stopped doing PR appearances and became an actual soldier and superhero.

Clint Barton’s brief introduction in Thor earned him the nickname “the hawk” from Dr. Erik Selvig (Stellan Skarsgård), but the deadly marksman’s moniker as “Hawkeye” was first revealed in The Avengers. In the same Budapest incident footage that featured Black Widow, Barton’s profile is shown, stating that he goes by the superhero name “Hawkeye.” It appears as though Clint was using the nickname for a while since his wife, Laura Barton (Linda Cardellini), even playfully called him that in Avengers: Age of Ultron.

It was clear from the first Iron Man film that Rhodey would eventually get his own suit just like in the comics, and despite the role being recast, that plan still pushed forward in Iron Man 2. Ironically, before he even became a proper superhero, Rhodey was already dubbed by Tony Stark as “War Machine” in the middle of their intense initial fight at the billionaire’s Malibu home. Rhodey also briefly used the “Iron Patriot” as his codename, but he eventually settled on “War Machine.”

Related: MCU Phase 4 Should’ve Used War Machine To Fix Tony Stark’s Repeated Mistake

Interestingly, Wanda Maximoff (Elizabeth Olsen) has yet to be called “Scarlet Witch” in the MCU. It’s worth noting, however, that in Avengers: Age of Ultron  Tony Stark called her “the witch,” referring to her ability to cast mind spells and create illusions. While Wanda has yet to be called her superhero name in the franchise, things are tipped to change via the upcoming Disney+ show, WandaVision, which will not only formalize the character’s persona as Scarlet Witch but also explain why she’s called that.

Originally Tony Stark’s AI JARVIS (Paul Bettany), the Vision was born accidentally in Avengers: Age of Ultron as part of the heroes’ efforts to take down the titular villain. The word “vision” was supposed to refer to Tony’s foresight. Later on, Ultron refers to the Mind Stone-powered android as “my Vision.” Eventually the name stuck – though Wanda affectionately calls him “Vis.”

Related: WandaVision Theory: How Vision Has The Mind Stone (Despite Infinity War)

Sam Wilson (Anthony Mackie) was already known as “Falcon” while serving as a United States Air Force pararescue airman, before retiring following the death of his wingman, Riley, in combat. He came out of retirement, however, after meeting Steve Rogers as he became a loyal comrade for the Super Soldier. The nickname “Falcon” refers to his massive mechanized wings that allow him to fly. Soon, however, Sam will take up the mantle of Captain America after Steve officially passed him the shield and the mantle at the end of Avengers: Endgame.

By the time Peter Parker (Tom Holland) was introduced in the Marvel Cinematic Universe, he was already operating as a street-level superhero for a while. As it turns out, Peter revealed his origin story on YouTube, helping Tony Stark to track him down. In light of how he got his superhero skills, he adopted the name “Spider-Man” as he revealed to his future mentor during their initial encounter in Captain America: Civil War.

More: Every Nickname Iron Man Gave Other MCU Characters Explained