"What's a Magneto? ...'Sabretooth'? 'Storm'? What do they call you? 'Wheels'? This is the stupidest thing I ever heard." —Wolverine, X-Men (2000)
Steven Ulysses Perhero finally got a role in the newest blockbuster film! Finally, the mainstream audience can be introduced to the awesomeness that is Grass Man!
...Except no one ever calls him that.
Throughout the movie, he's just "Steven Ulysses". We get all of one scene where he hints at casual drug use in college, saying his roommates used to call him "The Grass Man" with a snicker. Afterwards, they never use that name again, even when he gets the ability to control plants. Heck, even the end credits refer to the character as "Steven". What the heck just happened?
Simple: "Grass Man" is a name that the general audience might have a hard time taking seriously, and the producers knew it. Sure, that's what he's been called for forty years in comics, but there are very poignant reasons why people still have a hard time disassociating comic books with Campiness. Forty years ago, "Grass Man" might have been perfectly feasible for a character that can control plants, but nowadays, there's almost no way to use that name around the uninitiated without invoking a snort and a snicker. Hell, even a potentially "cool" name like "The Sabre" or "Dark Wolf" might seem a little too superheroic, especially if you're going to be calling someone by that name the whole movie. And on the villain side, it probably wouldn't make sense for someone to go through a traumatic experience and immediately start calling themselves "Dr. Destructo".
However, because the producers don't want to completely alienate the comic fans which supported the character to begin with, they add a little Shout-Outjust to appease them. "Grass Man" was definitely in the movie, even if that wasn't officially his name. They might even call the movie "Grass Man" without ever calling the character that. However, sometimes this trope gets taken Up to Eleven and the superhero name is never used at all.
In the case of long-running TV adaptations rather than movies, it's not uncommon for the writers to forget that they're using this trope after a while and accidentally use the character's comic book codename once or twice in a non-ironic fashion. Furthermore, it wouldn't make much sense for the hero to refer to himself and be referred to by his real name when around people who don't know his secret identity, so in those cases the code namehasto be used.
Related to Movie Superheroes Wear Black, Not Wearing Tights.
Note: Aversions must be notable. If we try to name every superhero film/media that averts this, we'll be reading this all day.
In general, the Marvel Cinematic Universe goes out of its way to subvert, lampshade, and defy the concept of a Secret Identity. None of the Avengers have one—not even Iron Man, who had one for decades in the comics. Tony himself mocks how pointless it is and defies the trope by outing himself in the last scene before the end credits.
Iron Man himself doesn't get called that name until the end of the first film and it's only used once or twice in the following films where he appears ("I am Iron Man" gets an echo in Iron Man 2 and Nick Fury refers to him as Iron Man once), but the name is also used in specific reference to the suit (i.e. "the Iron Man weapon" or "Tony Stark's Iron Man").
In Iron Man 2, the words "War Machine" are only used as an offhanded insult from Tony to James Rhodes.
As for the villains, Obadiah Stane is never called "Iron Monger", although he briefly says the word in reference to Stark Industries' role as a weapon manufacturer. Meanwhile, there's Ivan Vanko: a Composite Character of two villains named "Crimson Dynamo" and "Whiplash". He gets called neither in the second film, though the marketing referred to him as Whiplash. In Iron Man 3, Eric Savin and Jack Taggert go by their real names, and are never once referred to as "Coldblood" or "Firepower".
Iron Man 3 averts this, with both War Machine and Iron Patriot mentioned as codenames in popular and military use (lampshaded when Rhodey reveals that Iron Patriot "tested better with focus groups.") The Mandarin is also referred to as such, though the character Ben Kingsley played is ultimately revealed as a Decoy Leader and Aldrich Killian, the actual MCU Mandarin, is only called that once—by himself.
This gets even stranger in the short All Hail The King, where it's revealed that Killian wasn't the REAL Mandarin either, and had borrowed the name. The REAL one, though never shown, is naturally miffed at other people stealing his shtick.
In The Incredible Hulk, "The Abomination" aka Emil Blonsky goes by his given name and there is only an offhand referrence to that title once, when Dr. Sterns tells Blonksky that augmenting him with the Hulk's blood might turn him into "an abomination". The Consultant, in which the name Abomination is brought up but Agt Coulson says "[The World Security Council] really don't like when you call him that."
Averted by The Hulk, who is called "Hulk" four times. The first time comes after the Culver University fight, where some college students refer to him as a "big hulk". Later, the military guys chasing the transformed Blonsky through New York mistakenly report that "the Hulk is in the street." Blonsky explicitly uses that name after the Hulk shows up for the final battle and the Hulk himself uses his patented "HULK SMASH!" at the end of the fight.
In The Avengers, Bruce Banner notably takes pains not to call his alter-ego "the Hulk", preferring to call him "the other guy" instead. The one time he does say Hulk, he immediately corrects himself. But no one else has the same qualms.
Averted in the Thor films, where everyone's "superhero" identities are in fact their real names. Thor himself inverts it in the first movie, as the character once had a civilian identity in the comics, but the movies don't bother. So "Thor" is used all throughout the movie, while the name "Dr. Donald Blake" is the one that only gets a few token mentions.
The eponymous hero plays with the trope constantly. He only takes the name Captain America as a stage name, not as a superhero. Once he makes the transition to war hero, all of the characters call him Steve or "Captain Rogers" with a few exceptions (once by Bucky, once by Cap himself, and the other time by the Red Skull), and most of those examples are used as humor, irony, or mockery. Further, unlike in the original Golden Age comics, Cap does officially have the rank of "Captain", and since we've got various characters referring to him by "Captain", it's hard to know if they're using his stage name or military rank. By The Avengers, though, Captain America has become legendary and the name is in widespread use.
Johann Schmidt gets called "The Red Skull" (by Hitler, no less) one time as an insult, much to his annoyance. For the rest of the movie, only his real name is used.
Technically, this is also true of Montgomery Falsworth, aka "Union Jack", the British counterpart to Captain America. However, Falsworth is not a costumed hero in this movie so there would be no reason to say the name at all.
In Captain America: The Winter Soldier: Crossbones and Batroc the Leaper are only referred to by their civilian names, Brock Rumlow and Georges... Batroc. Rumlow may take up the name Crossbones in future installments. Sam Wilson is called "Falcon" by Maria Hill in the final battle, and this is also the name of the flight pack model he uses. The "Winter Soldier" codename is invoked frequently, but the heroes stop calling him this once they find out that he is Bucky Barnes. Red Skull is still dead, but when he's mentioned, he's mentioned as Red Skull. Finally, Sharon Carter is referred to as "Agent 13" throughout most of the movie, with Natasha only revealing her first name during the movie's last scene.
From multiple movies, Natasha Romanov's handle of "Black Widow" never comes up in Iron Man 2, and is only used in The Avengers twice. In the first instance, it was spoken in Russian, so anyone watching the film outside of its Russian dub actually only gets to read the name in subtitle form. Its other brief appearance is on the screen of a dossier Coulson is viewing. It's also not used very much in Winter Soldier, if at all.
In The Avengers, Clint Barton is called "Hawkeye" all of once by the Black Widow during the Battle of New York. It appears to be his radio callsign, with the name appearing briefly when Coulson is viewing his dossier in the film's beginning. The closest anyone comes otherwise is Dr. Erik Selvig semi-dismissively calling him "the Hawk". During his prior cameo in Thor it wasn't even alluded to.
This trope can be applied to the MacGuffin of Captain America and The Avengers. In the movies, it's called the Tesseract, or "the cube". They never use its comic book name, the "Cosmic Cube". However, it and other MacGuffins are collectively known as Infinity Stones, a name that is taken from the comics.
Franklin Hall and Donnie Gill haven't gone by their supervillain names, Graviton and Blizzard... but then again, they weren't supervillains yet.
A woman manipulates a pyrokinetic's ego by suggesting he adopt the name "Scorch," commenting on how nobody knows "Steve Rogers" but "Captain America" is a household name. Everyone who hears it is incredulous at the idea, including the pyro at first, but he warms up to it (pun not intended) and by the time S.H.I.E.L.D. shows up his embracing it is taken as a sign he's getting out of control.
Another episode concerns a device whose name is Russian and translates to "Overkill" in English; there's some snark that something must have been lost in translation but both names are used throughout.
The Big Bad is known as "the Clairvoyant"; although almost every character rejects the possibility of actual psychic powers, they keep calling him that because they don't have another name for him. They eventually are able to communicate with him directly, where the Clairvoyant says his subordinates coined the name and he himself finds it a bit overdramatic. Once he drops his cover he encourages everyone to use his real name. (And for the record, no, he does not have psychic powers; his "omniscience" is based in high-level SHIELD security clearance.)
Coulson's team discovers a super-soldier project codenamed "Deathlok", and they soon start referring to the project's subject himself as Deathlok completely unironically. Later in the first seasons it's discovered that there is more than one subject, at which point Deathlok becomes somewhat of a generic label.
Marcus Daniels is never called "Blackout" in dialogue, though eagle-eyed viewers can make out the name on his profile. The source of his powers is called the Darkforce, however, with requisite lampshading:
Parodied in Guardians of the Galaxy. Peter Quill introduces himself as "Star-Lord", but the guards arresting him just respond with confusion. When they later look at his rap sheet, they comment that apparently the only person who calls Quill "Star-Lord" is himself. The team's name "the guardians of the galaxy" is also mocked by the officer overlooking their arrest, who instead dubs them "a bunch of a-holes".
X-Men Film Series
This trope is played with all over the place. Codenames are something of a plot point; it's shown that the concept of a "true name" began with Xavier's eponymous "first class". However, it's originally used in playful jest and doesn't become serious until Magneto insists upon being called by that name at the very end of the film. In later movies, mutants seem to adopt codenames as their "true names" as evidenced when "Marie" changes her name to Rogue or when Magneto asks "John" what his real name is and he starts calling himself Pyro. Other than that, the codenames are used as Mythology Gags or Futureshadowing.
Cyclops' codename is mentioned but he mostly goes by Scott throughout all of the movies.
The name "Prof. X" is only used once, near the end of First Class, and Xavier brushes it off.
Jean Grey and Kitty Pryde never use codenames in the films. While their comic counterparts went through a few over the years, they usually go by their real names anyway (a rarity for superhero comics).
Magneto is often referred to as "Erik", although only by Xavier and Mystique, his oldest friends.
Wolverine goes by the name Logan almost exclusively and even mocks people with codenames. Stryker seems to be the only one who wants to call him Wolverine, which was more of a military-style Code Name. In the first film, it is mentioned that "The Wolverine" is a nickname he uses in his cage-fighting career, and in X-Men Origins: Wolverine he's inspired to take the pseudonym by a Native American folk-tale his wife tells him.
The Blob never gets called by that name. The best we get is a Lampshade Hanging where he mistakes Logan's "bub" for that name, and sees it as an insult.
The name "Gambit" is used a few times, though it's stated to be a prison nickname he was given by Stryker's guards.
"Bobby" has no codename in the first movie, introduces himself to Wolverine as Iceman in the second film, and is then called Bobby throughout the rest of the series until a brief moment in which Pyro picks a fight.
Colossus was referred to by his codename by Wolverine as they walked out of the Danger Room near the beginning of X-Men: The Last Stand. Beforehand, Wolverine calls him Tin-Man as a joke.
The name Nightcrawler is only mentioned when "Kurt" expounds about his time in the circus.
Angel (Warren) and Beast (Hank) never use codenames in X-Men: The Last Stand. Hank does eventually use the name towards the end of First Class, however.
Subverted and played straight with Jimmy in X-Men: The Last Stand as his profile indeed shows his alternative alias of "Leech", but he's never called that by anyone nor does he refer to himself as such.
Darwin from First Class is actually a nickname which happens to fit his powers, and his real name (Armando) is never referenced.
It gets a bit tricky with Angel (the First Class member as opposed to the one mentioned above); in the comics, her code name is Tempest, and Angel is her real name, but in the movie she explicitly states that Angel is a stage name.
Lady Deathstrike is never used. Her real name (Yuriko) is only mentioned in passing.
Played straight with the adamantium Powered Armor that is not explicitly called Silver Samurai. The moniker of Silver Samurai was named after a suit of samurai armor that serves as a Legacy Character for the Yashida generations.
Played with for Viper, who never calls herself "the Viper" but does says she's a viper.
Played straight with The Hand (mainly linked to the Daredevil / Elektra franchise, and ownership of those rights reverted back to Marvel before the film was finished), who are referred to as "The Black Clan" and led by Harada.
The X-Men series has a long tradition of ignoring this trope, but now it goes over the top. When Wolverine tells Xavier about his future, he advises him to search for people with certain names: Scott, Jean... and "Storm." Having just read Logan's mind, Xavier certainly would know who he's talking about, but still.
It's also played straight a few times. Quicksilver is never called by that name, for instance.
The Dark Knight Saga
With the series angling for a less outlandish and more "grounded" depiction of the Batman mythos, the films naturally use this trope extensively:
The Scarecrow is almost exclusively referred to by his last name Crane. The only times you ever hear the word "scarecrow" are 1) when one of Crane's victims, a delirious Carmine Falcone, utters the word over and over again, and 2) when Crane briefly calls himself "Scarecrow" while under the influence of his own gas.
In Harvey Dent's case, the name Two-Face is used exactly once, in reference to an old, derisive nickname given to him by the corrupt cops he used to investigate.
Anne Hathaway's portrayal of Selina Kyle is never once even referred to as Catwoman, and out-of-universe, even early press releases only referred to her as "Selina Kyle," fueling speculation that she would not be using a secret identity at all in the film. The only time "Catwoman" is ever close to being mentioned is a newspaper headline reading "The Cat Burglar Strikes Again" when Bruce is showing Alfred the background information he's pulled up on her. This may have become the best-known and most prominent example of the trope, to the point that various bloggers and reviews go out of their way to refer to the character as "Selina Kyle" and not "Catwoman". This makes sense when you consider the last time the character was referred to as "Catwoman" on screen, and how hard it flopped.
John Blake, the young police officer who aids Batman throughout the film and is implied to become his successor after Bruce Wayne's apparent death? Turns out his Embarrassing First Name is Robin. There is no comic character by the name of John Blake, and he never adopts a costumed identity of any kind in the film, with the broadstrokes similarities basically boils down to his backstory as an orphan, his apparent status as Batman's successor, and his vaguely sidekick-like role in assisting Batman throughout the film, making him perhaps the loosest adaptation in the series.
Batman's vehicle, the Tumbler, is never referred to as the Batmobile, either the black version shown in the first two films or the unpainted Tumblers driven by Bane's mercenaries in the third. However, his motorcycle and flying craft both receive bat monikers: the Batpod and the Bat (as opposed to the usual comics names of Batplane or Batwing), respectively. If "sounding less silly" was the objective here, names like "Batpod" and "Tumbler" are a lateral move at best.
The aversions in the series, meanwhile, are as follows:
Batman and Ra's al Ghul are commonly referred to as such. Oddly enough, in the comics, Ra's al Ghul is essentially the character's real name (it's complicated) but in the movie his real name is Henri Ducard.
In Batman's case, the film uses a mix of "Batman" and "the bat-man" to refer to him. The latter is generally less used in popular culture these days, but it sounds a tad bit less outlandish and treats the word "Batman" as less of a guy's nickname and more of a thing or a creature like "the snowman" or "the boogeyman," which fits in line with the whole angle of being a scary monster that terrorizes criminals.
"The Joker" has no known identity other than his Codename.
Gordon: Nothing. No matches on prints, DNA, dental. Clothing is custom, no labels. Nothing in his pockets but knives and lint. No name, no other alias.
Like the Joker, Bane never has his true name revealed in The Dark Knight Rises, and he goes by "Bane" exclusively, an element which is also true to the comics. It helps that, compared to names like "Mr. Freeze" or "the Mad Hatter", it's probably one of the easier names to use without raising too many eyebrows.
An entire scene played for laughs in Spider-Man 2 was dedicated to J. Jonah Jameson coming up with a good nickname for Doctor Octopus, only for him to mostly go by his real name or the nickname "Doc Ock" for most of the movie, as well as the real life advertising and merchandising.
Venom is known only by his real name, Eddie Brock, throughout all of Spider-Man 3. Similarly, Flint Marko is generally known by his real name for most of the film until a reporter calls him "the Sandman" during the final battle.
While Norman Osborn was called "Green Goblin" multiple times in the first movie, when it came time for his son Harry to adopt that persona, the name was never uttered. In fact, promotional material called him New Goblin, a name that was never used in the comics. The closest Harry comes to being known as the Green Goblin is when Peter mockingly calls him "Goblin Jr.". Harry himself strips most of the goblin styling out of the hardware, going for basic armor and a hoverboard in place of the spiky hang-glider (which makes sense, given that those spikeskilled his father...).
Averted in The Amazing Spider-Man. The mutated Dr. Curt Connors is referred to as "the Lizard" several times. Spider-Man himself, of course, is another clear aversion.
Played straight and averted in the sequel though. Spider-Man is called such very frequently. Electro refers to himself as such even when he's just being tortured and continues to when he becomes a proper villain. Harry, however, isn't called the Green Goblin at all. The Rhino gets very little screen time but is only identified by his civilian name (though he calls himself The Rhino). We also have "Felicia" but she doesn't become Black Cat within the film.
During the live action film adaptation of Casshern, the titular hero only refers to himself as "Casshern" once, and it isn't even near the climax of the movie.
The original Hulk movie also hardly used the term "hulk", the characters preferring to call him Bruce Banner, or "Angry Man". His father was never a supervillain so he never had a codename to begin with.
In the DVD commentary, Ang Lee notes that he didn't want to call him "Absorbing Man" and briefly calls him "Partaking Man", coming from David Banner's line: "I can partake in the essences of all things." But this name is never used in the film itself either.
Oddly, "Doctor Doom" would seem to be a perfectly sensible thing to call a person with a doctor's degree, whose last name is "Doom"* technically "von Doom", but people Anglicise such names in all sorts of different ways. In some of the dubs (the Brazilian one, for example), his line "Call me Doom" is changed to "Call me Doctor Doom".
Johnny himself only ever refers to his firey-headed alter-ego as the Rider.
While not a traditional superhero, Tarzan is a pulp hero who was an inspiration for the superhero genre and shares many elements. That said, in Graystoke: The Legend of Tarzan, he never goes by his more famous moniker but instead is called John or Lord Graystoke. Tarzan is never mentioned except for the title.
In Man of Steel, Clark/Kal-El is never directly called Superman. At one point, Lois almost says it before being cut off, and a soldier refers to him by the nickname to the confusion of his commanding officer. Presumably the soldiers got it from Lois.
In RoboCop (2014), after his conversion into a cyborg, Alex Murphy is only called "RoboCop" twice: Once by Pat Novak as a propaganda catchphrase, then later by his partner Lewis as a joke ("Good Cop, RoboCop"). Otherwise, he's mostly referred to by his real name, as unlike in the original trilogy, the fact that he's Alex Murphy is a matter of public record.
In The Punisher (2004) The Punisher spends most of the movie being called his first or last name, it is an origin story. There are only two references to his code name. The first is before the final battle, when he says what he's doing isn't vengeance but punishment. The second is the last line of the movie, where he says "Frank Castle is dead. Call me...The Punisher."
In the 1989 Watchmenscript by Sam Hamm, all the superheroes in the Cold Opening are referred to with codenames except Adrian Veidt. In the main action, when Nite Owl and the Silk Spectre come back into superhero action, they are still respectively named Dreiberg and Laurie in descriptive actions and dialogue headers. The name Ozymandias goes unused, but it's justified- Hamm's version of Veidt was never a superhero himself. His only involvement in the pre-Keene Act days was as a financier/quartermaster to the team.
When introduced, the Ultimate Marvel version of Emma Frost did not use the "White Queen" cognomen, as she (at first at least) had no connection to the Hellfire Cub.
In Nextwave, none of the members use their code names except for The Captain, and that's only because nobody knows his real name.
The Runaways started off with some code names, but dropped them almost immediately, except for one who insisted on being called "Princess Powerful." (note that she's a 12 year old girl...) Just as well, their code names sucked. The dinosaur still kept the name Old Lace to go with Gert's soon abandoned "Arsenic" codename, but anyway, she's a dinosaur, she does not have a "normal" name.
One of the reasons that Batman: The Dark Knight Returns is considered a notable move towards "Grim and Gritty" storytelling in comics is that it manages to go the entire story without referring to any of the superheroes (other than Batman) by their code names, thus making it easier to put the story in a real world context.
Secret Six: Catman simply goes by his civilian identity of Thomas Blake.
Very briefly during the Knightfall saga of 1993-1994, there is a storyline in which, shortly after the defeat of Bane, one of Gotham City's mobsters enlists the services of "Mekros" to take down Batman. Nobody ever learns Mekros's real name (the mob boss even refers to him as "Codename: Mekros", which is also the title of the story) or even sees his face, because he is a masked, cybernetic, brainwashed assassin who is a product of the CIA's legendary "MK-Ultra" project from the Cold War (which gets a Continuity Nod a couple of years later when Batman faces off against a woman who is the product of that same program, although Mekros is never named again). However, Mekros himself never uses the name Mekros, for the only reason he ever speaks at all is because he's been programmed by mind-bending drugs to endlessly recite passages from Machiavelli's The Prince, the most prominent of which is "Only the Phoenix survives chaos." Thus, more naive readers could have been forgiven for assuming his codename was "The Phoenix."
A one-off Superman villain in the early 2000s eschewed giving himself an alias, instead using his given name, "Gabriel Van Daniken." He even mocks the practice of villains giving themselves code names:
"You think just because I put on this battlesuit, and threaten to poison the water supply, I have to give myself a ridiculous-sounding alias? Get a grip, Superman. I'm thirty-five years old!"
Done via retcon for Hal Jordan's nemesis, Sinestro. "Sinestro" was originally just his supervillain title (an obvious play on "sinister"), but as he was fleshed out as a fallen Green Lantern who went rogue, it was decided that "Thaal Sinestro" was actually his real name. Calling him "Sinestro" is the equivalent of calling Lex Luthor "Luthor".
Green Arrow: During the 80s run by Mike Grell when he lived in Seattle, Ollie abandoned most of the "superhero" trappings of his life, including the name "Green Arrow". In the entire 80-issue run, he's never referred to by that name. People usually call him Ollie or "That Robin Hood lookin' dude."
Played with by X-23: She wasn't even given a real name until she was thirteen years old, when her dying mother, Dr. Sarah Kinney, named her Laura. Until that point, she was either referred to by her Facility code name, X-23 (derived as her being Sarah's 23rd attempt to create a female clone), or various insults (particularly as being an animal) to dehumanize her. Her official codename with the X-Men, Talon, is almost never used or referenced. Most of her friends, loved ones and teammates just call her Laura, and occasionally they'll use "X" as a sort of nickname. X-23 is used much less frequently within the books, though is how she's typically marketed.
Clark Kent is never referred to as Superman, though the word is mentioned multiple times in reference to Friedrich Nietzsche. The traditional "Superman Created by Jerry Siegel and Joe Shuster" message appears in the intro.
Because of its Prequel state, most characters aren't referred to by codenames, as the incidents that led to them adopting these names haven't happened yet. Green Arrow is the first to do so, and we'd known him for more than a full season when he started using it.
It takes a weird turn when Clark finally becomes a full time but covert crime fighter and is dubbed with the comparatively unimpressive name "The Blur", which is used frequently even by him.
Clark finally starts using the Superman persona in the Grand Finale, and by the epilogue seven years later his alter ego is known to the world by that name, but "Superman" is used to refer to him only exactly once by Chloe.
The Heisei-era* post-1998Kamen Rider series vary in this respect, asserting the autonomy of their own universes from each other (at least until Kamen Rider Decade screwed with their timelines and the subsequent team-ups), with only a handful of series actually calling their warriors "Riders:"
Kuuga was frequently referred to as yongo (No. 4), in reference to his being the fourth "unknown being" the police force encounters, lumped with the villainous Grongi. (In fact, one of his modes is Unknown Lifeform No. 2; The white Growing Form and the red Mighty Form aren't known to be the same guy by the authorities at first.) Only a few people know the term "Kuuga," and the term "Kamen Rider" doesn't exist outside the opening credits.
Agito, a loose sequel to Kuuga, has its hero initially confused to be a returning Kuuga/Yongo/No. 4, and was unique in the respect that a handful of chosen people implanted by the Seed of Light can become Agito themselves. So Agito is not so much a unique warrior of justice than a step in human evolution.
Faiz was never referred to as a Rider, and neither were the similarly-themed Kaixa and Delta systems and their users. When Kaixa first appears, the side-characters are surprised to see "another Faiz," not "another Rider." The series being a really ambiguous world as it is, with these systems created by the more-megalomaniac elements of the Orphenoch race (here again, another step into human evolution), it probably fits.
Averted in Kamen Rider Blade. The term is used like in any of the early series, with a guy who wants to write about them as one of the supporting characters. It is (perhaps intentionally) hard to tell if he means these Riders (active for a little while pre-series) or all Riders when he talks of the deeds of Riders past. On top of that, the belts are actively called "Rider Systems" by their creators
Hibiki and his fellow warriors are precisely called "Oni", never "Riders." This being an adaptation of another independent Ishinomori series (Ongeki Hibiki) reworked as a Kamen Rider series, it is the source of contention among the KR fandom.
Kiva (and for that matter, Saga and Dark Kiva), were considered as "armors" to be worn by the villainous Fangire leaders/kings when their Fangire forms are not enough. And for that matter, the secondary Rider (the IXA system) was never called that as well. The "IXA System" was referred to, but not "Kamen Rider Ixa" as a name. "Kamen Rider" itself was rarely heard - when Ixa's first seen user says "My Rider System is much stronger than his," this may be the only time. Kiva did have the same head writer as Kamen Rider Faiz.
In Kamen Rider Double, the people of the city gave their hero the name Kamen Rider. (Past Rider knowledge, or due to their hero having a Cool Bike and wearing a helmet, making him obviously a 'masked rider?' Good question.) and never use the name Double. People in the know primarily use "Double" and not "Kamen Rider." (This means the full title "Kamen Rider Double" isn't something you hear much or at all outside teamups.) Shotaro and Philip have adopted the "Kamen Rider" title and are protective of it - initially it's just for them, but after meeting some others, they're willing to consider you a Rider if you uphold the ideal. Riders aren't just anyone in a shiny suit, they're heroes who fight "those who make the city cry." Villains with transformed states that happen to have bug-eyes and antennae are not Riders to them and they'll make that known right away.
Later series played with how the name "Kamen Rider" came to be. In Kamen Rider Fourze, Goth Tomoko was aware of past Riders as an urban legend, and so applied it to Fourze ("rider" never comes up when the suit's being explained to the hero at first.) and later Meteor. In Kamen Rider OOO, Kougami seems to know about Riders, so Birth is "Kamen Rider Birth" (it's even in the suit's instruction manual!) but OOO is only called a Rider during crossovers.
Kamen Rider Wizard plays by the rules of the early 2000s' series. People who know him call him Wizard (in English) as opposed to "the ring-bearing wizard" ("wizard" in Japanese, as mahoutsukai.) The term "Kamen Rider" has yet to come up in any way outside teamups. The Rider-like mystery figure that gave him his Wizardriver is known only as the shiroi mahoutsukai ("White Wizard"), and when Kamen Rider Beast arrives, it's like Faiz all over again: people are surprised to see another 'wizard.' He even introduces himself as "the wizard Beast", while the villains call him the inshie no mahoutsukai ("Ancient Wizard"), or "Archetype".
This brings up an interesting point: even if a character does not share an origin with any other Rider, and the term never comes up and never has a reason to, when he finally meets other Riders, he will know the term, maybe even using it as if he always has. Nobody ever says "Kamen who?" except in Fourze, where again, Tomoko applied the term to Fourze and Wizard due to their similarity to Riders past. Fourze introduces the term to Wizard on their first meeting, and the latter gladly adopts it because the idea of "masked heroes who fight humanity's enemies in secret" sounds pretty cool. Meteor actually gets mildly offended at Wizard's flippant attitude, saying "Don't take the Kamen Rider name so lightly!", but Fourze calms him down.
Played with in Kamen Rider Gaim, where the local DJ gives our hero his name... but that name is Armored Rider Gaim (as an armored member of the Team Gaim dance crew, where such crews are called "Beat Riders"), and "Armored Rider" becomes the term used for the series' warriors instead of "Kamen Rider". Like with other shows, the phrase "Kamen Rider" is used in crossovers, though Gaim is one of the rare ones that goes "Kamen Who?" at first.
When Haruto explains to him how not being able to ignore the cry of someone in need is what makes a Kamen Rider, he accepts the term. However, in the Gaim series proper, though it has yet to be discussed, it proves to be very appropriate: with most Riders out for themselves a la Ryuki and can't be bothered to go fight monsters to protect people when it won't get them anything, it becomes pretty clear that the series may have many characters in armor but only one true Kamen Rider.
Though it's said in the movie section, just for the sake of completeness: Kamen Rider The First and Kamen Rider The Next never use the term. Shocker calls Riders 1, 2, and V3 "Hopper version [number]" only, and no name is ever used by people who don't know those names, dialogue written so as to not make it awkward that they don't.
In The Incredible Hulk TV series, reporter Jack McGee and his readers often use the name "the Hulk," but most characters (including the Hulk's alter-ego David Banner) just say "the creature."
In Arrow, a CW series based on Green Arrow, that name isn't used until halfway through the first season, when Malcolmof all people suggests it during a dinner conversation, only for Ollie to shoot it down as "lame". He also isn't initially called "Arrow" - he spends the first season being referred to as "The Hood" after his costume design, or just "the vigilante," and has to specifically ask people to start calling him The Arrow after he takes up a Thou Shalt Not Kill policy in the second season. It has been hinted by Word of God that he will eventually be called "Green Arrow".
Zig-zagged with Deadshot, aka Floyd Lawton, who is known to the CIA by that codename, but is mostly referred to by his real name.
Count Vertigo, reimagined as a drug lord, goes by the Count with the drug he peddles called Vertigo. In the second season however, he officially starts calling himself Count Vertigo.
Firefly never uses a codename but it is the name of the team of firefighters he was a part of.
Perhaps the strangest example is Merlyn the Archer. In the comics that's a code name he chose due to his obsession with Arthurian myth, in the series it's his real name. His "Dark Archer" persona is only ever named in advertising materials for the show.
Barton Mathis is referred to as Dollmaker, and is justified in this case. In the show, he's a flat out serial killer rather than a supervillain, and "Dollmaker" was the name given to him by the media in reference to the manner in which he murders his victims.
A.R.G.U.S. refers to Slade Wilson by the codename "Deathstroke", but the name didn't exist during the island flashbacks and he and others generally use his real name in the present.
Sara Lance does use the name "The Canary", a name she chose after joining The League of Assassins, instead of the comics Black Canary.
Bronze Tiger also breaks the rule.
Although the Hellboy films avert this trope, the toyline for the second movie does not. The first movie's toys, sold only in specialty shops, were sold under the "Hellboy" title, and featured the character's name on the packaging; the second movie's toys, sold in Toys R Us, were apparently from the movie "HBII," and the main character was "Red."
The movie toys for Kick-Assgo out of their way to avoid putting the word "ass" anywhere on the packaging. The toys for the second movie went so far as to have "uncensored" package variants sold as an exclusive.
However, Robin calls him "Clock King" in "Time Out of Joint", and in the Justice League Unlimited episode "Task Force X", Colonel Flagg presents him as "Temple Fugate, a.k.a. The Clock King" to the rest of the Task Force.
In Batman the Animated Series, Count Vertigo is known simply as "Vertigo", which is his Code Name in the Society of Shadows.
In The New Batman Adventures, Catman just goes by Thomas Blake. He also wears a black outfit rather than his colorful comic book costume.
Though again, this may simply be keeping up with the comics, where the rest of the League has used his name almost solely for some time. Similarly, Wonder Woman is usually just "Diana" to the others, both in the comics and DCAU.
Aquaman's brother Prince Orm never adopted his moniker of Ocean Master. In fact, Bruce Timm flat out said he considered Ocean Master to be too silly a name to take seriously.
Jean Grey is never called Marvel Girl. But it had been a long time since the comic book version had used a codename anyway.
Zebediah Killgrave also never uses the name Purple Man. It helps that Killgrave is a pretty badass last name in its own right.
Due to Never Say "Die", DC villain Deathstroke went by his civilian name "Slade" throughout the animated Teen Titans series. (It probably helps that "Slade" sounds like a codename without the "Wilson".)
Especially if you don't know they're saying his name (Slade), and instead think they're saying the past-tense of "slay" (Slayed.)
Recently, an ad for an episode of Arrow used the pun. "Get Slade or get slayed!"
Inverted with the Teen Titans themselves. In the comics they refer to each other by name when they're being civilians or aren't in public but the cartoon never has them refer to each other by names. It's implied that they don't even know each others names; the gang are shocked when they learn Beast Boy's name is "Garfield", when they always call him "Gar" in the comics. On th other hand, Raven is her actual name, and Starfire is less a pseudonym and more a direct translation. Though she is referred to as Koriand'r once in a line of Tamaranean dialogue, she's just Starfire to her teammates. Robin, however is not any one specific Robin. Word of God says that he is meant to represent the concept of Robin rather than any one incarnation. The tie-in comics establish him as Dick Grayson, but he's closer to an amalgamation of Dick Grayson and Tim Drake, with the odd bit of Jason's attitude.
In G.I. Joe: Renegades, General Hawk is only referred to by his real name, Clayton Abernathy. Likewise, a flashback to Duke's past has Tripwire merely referred to by his real name, Tormod Skoog.
In Avengers Assemble, the Space Phantoms don't refer to themselves as such. Instead, it's just an offhanded name Captain America gives them since he has no idea what they're actually called. Hawkeye even stops to point out how incredibly ridiculous "Space Phantoms" actually sounds.
Candi has to actually tell the reporter that "Ciem" sounds like a good abbreviation for "ciempies." But other than instances where there is no choice but to call her by that name, most characters take pains in the books to avoid ever using the word "Ciem" at all.
Likewise, Jeral Cormier is only routinely referred to as "Botan the Plant-Man" by the media. Those who know him will almost never use the name; calling him Jeral all the time. Some strangers know him as "Derrick of the Dandelions," and prefer that over calling him Botan.
After learning about the AI backvisor that was controlling Jeraime, Candi always insists on distinguishing between Jeraime and "Musaran" with the latter referring to the AI.
Jack has the codename of "Jackrabbit" because of his jumping ability, but has no real way to conceal his identity. So the nickname proves to be useless and everyone calls him Jack anyway.
Inverted with the Chinese spies, whose real names were not revealed until they were published to the wiki in 2011. Black Rat, Tin Dragon, Teal Hog, and Stung Hornet are known almost exclusively by their codenames, even to each other. Possibly justified in that they're spies.
Played with in the films. Hellboy's real demonic name is not known to him until towards the end of the first movie. He grew up with the name Hellboy and since his other name is tied with the destruction of all mankind and wasn't known until he was about 70, he kept it.
While on cases, the BPRD paranormal agents usually use names such as "Sparky" and "Blue". His is "Red".
It should also be noted that in Hellboy, demons have the whole "bound/released by their names" deal going on; going around calling himself Anung Un-Rama would be the equivalent of legally changing your name to your social security number.
His name is mentioned at the end of the second film by Princess Nuala, when her twin brother Nuada questions Hellboy's right to challenge him. Since Hellboy is really demonic royalty, he does have the right to challenge Nuada.
The Joker names himself as soon as he reveals himself to his first victim - whom he promptly kills. Interestingly, the first time he makes his name known to the public, he uses "Joker" as the name of the brand of (poisoned) beauty products he's advertising on television, never explicitly stating that that's his name as well (at least not until late in the movie, when he hijacks another TV broadcast and announces "Joker here", ironically while disguised by flesh-colored makeup). Nevertheless, that is just what he is soon being called by the media and by all the other characters.
The name "Catwoman" spreads quickly in Batman Returns, even though Selina Kyle tells only one person that that's her new codename. However, most of the other characters do not call her that, usually only making smart remarks about how she looks like a cat ("Just the pussy I've been looking for!" or offering her "a very big ball of string"). The only exceptions are tabloid newspaper coverage ("I read that Catwoman is supposed to weigh 140 pounds") and one of the Penguin's speeches:
Penguin: I may have saved the Mayor's baby, but I refuse to save a Mayor...who stood by, helpless as a baby, while Gotham was ravaged...by a disease that turned Eagle Scouts into crazed clowns, and happy homemakers into catwomen."
With The Riddler, there's a scene dedicated to him thinking up a code name for himself. Other names he considered are "The Puzzler" (name of an actual villain from DC Comics), "The Gamester", and "Captain Kill".
The Penguin in Batman Returns goes by both his real name and codename quite frequently. The prominent use of his real name is justified as part of his original plot to murder all of Gotham's first born children; when he reveals himself to the public, he puts on a big show for the media of him "discovering" his real name to be Oswald Cobblepot in order to gain private access to Gotham's public records. This likewise apparently plays into his new Villain with Good Publicity ploy to become mayor. When Batman eventually foils his scheme and he suffers his Villainous Breakdown, he's apparently revealed to care nothing for his real name when, in response to a henchman calling him Oswald, he angrily snaps that his name is Penguin.
Although not based on any specific comic book or manga, Pacific Rim is still based on manga/anime properties and notably averts this trope. Directed by Guillermo Del Toro (of Hellboy fame, also on this list of aversions), the movie unabashedly embraces the tropes of manga and anime, including giving each and every one of the Kaiju and Jaegers a Code Name.
The Ultimate X-Men comic goes to some trouble to justify why these kids should have codenames, beyond "because it's a basic trope of the genre". Apparently, these are their "mutant names", as distinct from the "homo sapiens names" their parents gave them.
This is also touched on during the Grant Morrison run on New X-Men as part of his efforts to give mutants a sub-culture.
Averted in the Blade series. The audience learns that Blade's real name is Eric but it is rarely mentioned.
Ditto for Blade The Series. The only mentions are the flashback episodes to his childhood and when he meets his father, who will not call his only son "Blade".
Averted with Rorshach in Watchmen since no one knows his real identity until the mid-way point. Even then, he prefers the name Rorshach. Other characters oblidge since they never knew him by the name Walter Kovacs anyway. Also, Edward Blake is called by his real name, and his codename, The Comedian, interchanging it scene through scene. All the Minutemen are also called by their codenames only, just Hollis Mason (Nite Owl I) and Sally Jupiter (Silk Spectre I) being given their real names in the film. Nite Owl II and Ozymandias are called mostly by their real names, except on a couple of instances.
Averted in the G.I. Joe Films. The Joes and Cobras are referred almost exclusively by their codenames, even in official capacity.
Averted in Godzilla (2014). Despite rumors that Godzilla would not be referred to as such in this film, Dr. Serizawa introduces him during the briefing as "Gojira" and the military uses the name Godzilla as a code name for the beast. News broadcasts even dub him "King of the Monsters."
Averted in The Wolverine by Wolverine who calls himself The Wolverine at one point.
Decades ago, in order to make news more memorable, rather than use real names, news networks often used nicknames and codenames. Even in more modern eras, this is used when the real name of an individual is unknown or deliberately withheld. For example, "The Unabomber" is a better-known name than "Ted Kaczynski" and "Girl X" is better known than "Shatoya Currie". However, when the real name is known, the news tends to use it, if only to be respectful.
In sports, most noteworthy players, such as "Orenthal James ("OJ" or "The Juice") Simpson, Michael ("Air") Jordan, or Earvin ("Magic") Johnson. In the latter case, his nickname is more known than his given name.
If a writer, musician, artist, etc. achieves fame while using a pseudonym, chances are they'll be far better remembered by that than by their birth name. While sometimes these pseudonyms are outlandish enough to indicate otherwise, there are times when the pseudonym can seem less outlandish than the person's actual name. Case in point: how many people would guess that Anne Rice's given name is Howard Allen O'Brien?