Secret Identity Change Trick

Often, a Superhero with a Secret Identity faces situations where he must change into his superhero identity, and do so without revealing the identity.

This calls for a Secret Identity Change Trick, and fast. Usually, the superhero will try any excuse and/or use any situation to his advantage in order to change.

Bruce Wayne Held Hostage is a specific variation. See also We Need a Distraction. If the hero isn't very good at it, he may claim he needs to go iron his dog.

Anime and Manga

 * Done oh-so-often in Sailor Moon, but most notoriously in the unusually humorous and self-aware episode 184, where the entire team, as well as the villains, happened to gather in Usagi's house, and she had to run through the rooms looking for a place to transform without revealing her secret identity to the Three Lights. (Who, in turn, had to find a way to transform without revealing theirs.)

Comic Books
"Peter: "Oh, I, uh, just remembered..."
 * In an issue of Damage Control where Speedball (not Penance) tries to find some satisfactory way to go change into costume when supervillains attack... then tells everyone he's going to go get a frozen yogurt.
 * This happens all but constantly when Peter Parker has a secret ID. His running off every time there's trouble generally makes him look like a coward and causes him to miss all kinds of engagements.
 * Probably his best excuse came in The Spectacular Spider-Man: "A green guy is holding my boss hostage, and he wants me to come take pictures. Otherwise I might get fired."
 * Spectacular also subverted the trope by exposing the lie once (though not the reasons for making it); After Doc Connors becomes the Lizard, Peter makes the lame excuse as usual and everyone assumes he's just freaked out - but the next morning everyone sees Spidey and the Lizard in the paper with the byline "Photos by Peter Parker", making him look uncompassionate and selfish.
 * A classic subversion of this came in the issue where a D-list villain attacked Peter in his apartment while Mary Jane was there and he had to shove her into another room while he dealt with said villain. After he runs the guy off and is scrambling for another lame excuse to give MJ about what happened, she drops the bomb on him that
 * The two undisputed kings of this trope, Spider-man and Superman, had an opportunity in the late 1990s to perform this on each other. During the massive Marvel/DC crossover, where characters from either universe get cosmically transported to the opposite universe. IE: Spidey winds up in DC, Robin winds up in Marvel, etc., freelance photographer Peter Parker gets assigned to work with reporter Clark Kent (and the publisher didn't notice the alliterative awesomeness?). Naturally, while they're out covering a story, something goes down. Spider-sense goes off, super-hearing picks up trouble. Despite their practice at keeping secrets, they both start an excuse and don't even finish it. (classic)

Clark: "Yeah, there's this thing I have to, um...""


 * After his identity as The Flash became secret again, Wally West had to start doing this sort of thing. In one instance, when there's a problem at a social gathering of some sort that he and Linda were attending, he does his standard take-off-so-fast-no-one-sees-it routine, leaving a note in Linda's hand along the lines of "make my usual excuses," thus indicating that (unlike some character's off-the-cuff and often strange excuses for running off) they'd quite possibly discussed and planned for such situations.
 * Subverted in the unreleased 1940 Superman story "The K-Metal From Krypton". Circumstances (temporary power loss) trapped Clark Kent, Lois Lane and two thugs in a mine with a dwindling oxygen supply. Unable to easily sneak off to change, Clark simply opened his shirt in front of everyone. The two thugs were said to be too "dazed" to notice what was happening, but Lois was lucid enough to notice and Superman even confirmed to her that she was not hallucinating due to lack of air. Apparently, the plan was to have Lois brought in on Clark's secret permanently, but the idea was vetoed by National Comics (and thus the story was never published).
 * One Superman comic indicated that, for his time as Superboy, Clark's father used a long-expired bottle of medicine as an excuse for Clark to go running off.
 * Another Superman comic of that vintage (1970's) had Superman having a nightmare about a huge disaster and no way to go and change, with his entire supporting cast bitching at him for his stupid excuses. Especially Lois complaining about his "three hundredth 'Queasy Stomach' routine."

Film

 * The first Christopher Reeve Superman film -- Clark has to change into Superman, but there seems to be no place to hide to do it. However, Clark finds and runs through a revolving door at superspeed, fast enough to be invisible as he changes clothes and comes out as Superman. This sequence includes a Mythology Gag where Clark first stops and stares at a modern "bubble on a pole" public telephone, in obvious evocation of the older comics and cartoons where he would change in an old-fashioned wooden phone booth.

Live Action TV

 * In the live-action version of Wonder Woman with Linda Carter, Diana Prince was always running off as if she was scared, only to return as Wonder Woman. Two examples include:
 * In one episode, terrorists are holding everyone hostage. Everyone is standing there with their hands in the air. Diana Prince (a supposedly highly-trained secret agent of the IADC at this point) takes off running through the crowd. Her actions don't cause panic or get anyone else to flee and the terrorists don't bother shooting her, although they had the ability to do so.
 * In another episode, aliens have landed in a field. Steve Trevor, Diana Prince, and a bunch of soldiers are sent out to meet with them. When Diana realizes she could do more as Wonder Woman, she casually walks away only to return to the exact same spot dressed as Wonder Woman. No one realizes that this tall, attractive brunette walked away, changed clothes and returned.
 * Despite Diana's cowardice, she never gets in trouble for running away from danger, essentially abandoning her job and endangering civilians at the same time.
 * Lois and Clark had fun with this one, and Clark's inability to come up with a good excuse for why he had to leave. The epitome of this being "I have to go pick up my cheese of the month package." Sometimes his parents -- and later -- would have to cover for him with equally lame excuses.
 * This was why David Banner constantly had to walk away from the love interest of the week down a long dirt road to the sounds of sad, sad piano music in The Incredible Hulk TV show in the Eighties. If he'd stayed in one town for more than a few days, eventually he'd transform multiple times and people would realise that David Banner was there every time the Hulk appeared. Also, although David Banner didn't do this part on purpose, he would usually get conveniently shoved out of sight somewhere, leaving everyone to wonder where he went and where the big, green monster came from.
 * In the Monty Python's Flying Circus sketch "Bicycle Repairman", the title character uses a ridiculously transparent version of We Need a Distraction to get everyone to look away so he can change without revealing his secret identity.

Web Original

 * Breanna Mae Siegert, better known as Bungie of the Global Guardians, once used the excuse "I've got to take my poodle to the post office. She's expecting a very important package" in order to get away so she could change into her costume. The other players thought this was so funny they started using it as a Stock Phrase everytime their character needed to get away to change into their Secret Identity.
 * In Act I of Doctor Horribles Sing Along Blog, this is Played for Laughs by having Dr. Horrible change from street clothes to his supervillain outfit by ducking beneath a concrete wall for about half a second, mid-verse. There's even a tiny sound effect to sell it. The commentary points out that it took Neil Patrick Harris so long to change during filming that they had to play tricks with the lighting to make the scene come out right, and this is just barely visible if you look closely.

Western Animation

 * In Superman: The Animated Series, Bizarro shows up and begins menacing the Daily Planet offices. Clark kills two birds with one stone by first confronting Bizarro and goading him into throwing him out a window, and then reappearing as Superman, justifying his sudden appearance by explaining that he'd just "rescued" Kent.
 * In the superhero episode of Futurama, Bender and Leela quickly find reasons to leave the room when their hero personas are needed. Leela states that she "left [her] apartment on fire," and Bender mentions having to study for the LSAT's. Fry, unable to come up with a good excuse, declares "And I can't take life anymore!" and leaps out the window before promptly leaping back in dressed in his costume.
 * In The Adventures of the American Rabbit, Rob Rabbit tells his Jackle captors that he's the tap dancer of the band. They scoff and the senior Jackle demands he dance (over the objections of his partner) and Rob complies. In doing so, he manages to dance out of sight before the Jackles realized he's escape. By the time they turn the corner in pursuit, Rob's already changed into the American Rabbit and tackles them.
 * In the He-Man and the Masters of the Universe episode "The Shadow of Skeletor", Prince Adam changes into He-Man right in front of Teela.
 * Jem could project a hologram of either her or Secret Identity of Jerrica, using her earrings, if they both needed to be in the same place, but the hologram wasn't solid. At one point she ran towards the hologram of Jerrica and as they passed close to each other they switched and Jem became the hologram while Jerrica returned to normal. When she needed an off screen switch, usually because somebody asked for the other person, she'd run off with a "Oh there she is I'll go get her" or have her bandmates run interferance.