When a character either suddenly appears or disappears close to someone when they weren't looking; to start or end a conversation. Maybe they teleported, maybe they used amazing ninja-like abilities of stealth and concealment, but they're just so good that whoever they're talking to wasn't even aware of it.
An integral part of the Stealth Hi/Bye is that not only doesn't the character see the actual entrance/exit, but neither does the audience. Often there will be a pan of the room first showing that nobody is there, a close-up of the "victim" and then suddenly there they are.
Mysterious beings will often use the Stealth Hi/Bye to disappear as soon as the person they're talking to looks away, possibly because a third party comes into the room. (The third party will never see the person engaging the Stealth Hi/Bye.) There will always be some minor distraction making the "victim" glance away for a second, even if they're familiar with someone doing this. The camera will also pull away from the hero, thus the audience won't see how they disappeared. Sometimes, the hero might even somehow disappear unnoticed while offscreen even though the surrounding characters are positioned in a way that should let them see how the hero departs.
Occasionally, will be pulled off in such a way as to make it appear that the one pulling off the Stealth Hi/Bye is still in view of the other person.
This tendency is usually not really explained, but common possible interpretations would be a character who is able to teleport/turn invisible or else moves very quietly and/or quickly. Although to some extent this ability can be used in Real Life, most of the time this ability is exaggerated to the point where it is an example of very soft/implausible SF, and at times relies heavily on the Rule of Cool in order to avoid breaking Willing Suspension of Disbelief.
This is one of Batman's two signature entrances/exits, the other being a Super Window Jump. He does this pretty reliably when talking to Commissioner Gordon or his other allies.note The earliest known example of him disappearing on Gordon is in 1973's Swamp Thing #7. In fact, whenever he doesn't it's usually a sign to Gordon that it's an impostor, or at least that something's wrong.
In the Knightfall novelization, Batman appears in Gordon's car, impliedly having snuck in while he was out. Gordon asks him if he's a ninja, and Batman says yes. After their conversation, Gordon brakes at a stoplight, makes a few quips, and turns around, only to find that Batman is gone. In defiance ofseveral laws of physics.
Interestingly, in the Knightfall comic, Jean-PaulValley's failure to mysteriously disappear during one of his talks with Commissioner Gordon becomes Gordon's first clue that he isn't the real Batman. Indeed, Gordon is nearly stunned to speechlessness when he turns around in mid-sentence to find Batman still sitting there.
Gordon: [...] ...Blame him... My God. Azbats: Something wrong, Commissioner? Gordon: You're still here. Azbats: So? Gordon:Usually I turn and you're gone. Azbats: I wasn't certain we were finished talking. Gordon:That never stopped you before. Azbats: I'll be going then.
He's even been able to pull this off on Clark Kent (also known as Superman) a few times. e.g.: During JLA: Midsummer's Nightmare, where Batman asks the JLA to wait a moment while he goes on ahead to quietly disable a sentry. Superman and J'onn J'onnz both try to follow his progress, but fail. To reiterate: a guy who can hear electrons bump into each other on the other side of the planet and see DNA through a mountain, and a guy who is a Xavier-class telepath and possesses nine senses, both utterly fail to detect Batman when they know where he left from, when he left, where he's going, and that he'll be back in a minute. It has been noted in the past, however, that Batman has mentioned that he's gone out of his way to learn how to trick Superman and others (usually more by way of mindgame stealth) — in the first issue of Grant Morrison's run, Superman doesn't hear Batman's heartbeat, his usual way of picking up on him as he approaches; Batman muses that "the device worked". Similarly, Batman has been able to block out telepathic detection on various occasions if he knows about it. And on a number of occasions, other superheroes have asked Superman how Batman could disappear on him like that, and Superman only grins affectionately and says, Batman loves his little tricks, leaving the impression that Superman has no desire to make an effort to spoil Batman's fun. The few times Superman has truly had to catch Batman, he has been able to do so... usually with Batman chastising him that he took 14 seconds longer than Batman himself expected.
In Kingdom Come, Superman pulls this, albeit unintentionally, on Batman. Batman proceeds to wryly comment to himself: "So that's what that feels like...." And toward the end of the book, when Clark and Diana (Wonder Woman) are waiting at the diner for Bruce to show up, Clark worries that someone will recognize them. Diana tells him it isn't likely, then Bruce interrupts her by saying that none of them stand out. Clark's response?
Superman: There you are. You snuck up on me. Me. How do you do that?
Superman does it intentionally to Batman by showing up suddenly more than once (such as the first issue of Superman/Batman), usually to Batman's annoyance, with Superman noting that he loves being able to surprise Batman like that.
On one occasion, Batman deliberately subverts this; since they are investigating a crime in the suburbs, with no high roofs for him to jump from and vanish, he simply drives away in the Batmobile, leaving Gordon nonplussed.
The first character to do this to Batman was The Phantom Stranger, another DC comics nighttime hero (though a supernatural one, so it was not really that he was more skilled than Batman). When Phantom Stranger pulled this on Superman, he comments, "At least Batman has a heartbeat to listen to."
Most members of the Bat Family (Robin, Nightwing etc.) have done this at one time or another — obviously they learned from the best. Barbara Gordon (a.k.a. Oracle, formerly Batgirl) once pulled this on Catwoman in an art gallery. In a wheelchair.
At one point, during the No Man's Land arc, Gordon is in the middle of a What the Hell, Hero? speech to Batman and points out that friends do not walk out in the middle of your sentences. Batman was more open and above-board in his dealings with Gordon for the rest of that arc.
During the Knightfall storyline, Gordon briefly talks with Robin (Tim Drake), who disappears halfway through Gordon's sentence. Gordon's response is a Funny Moment for a notably downer storyline: "...I bet it's the first thing he teaches them."
In The Widening Gyre, Batman and Nightwing are talking, Batman looks away for a moment, and when he looks back, Nightwing is gone. His response?
Nightwing himself would, during his tenure as Batman, surprise Gordon when he didn't disappear like usual. Unlike with Jean-Paul Valley, Gordon wasn't alarmed...just a little weirded out. The reason Gordon is comfortable with this may be that he's implied to know that Dick Grayson is Batman.
In Birds of Prey (the TV series), Huntress is constantly doing this, especially to her Friend on the Force. At one point, even Alfred did this to him, prompting him to say something to the effect of "you've gotta be kidding me."
The first issue of Red Hood and the Outlaws has this being pulled on former Robin, Jason Todd. Apparently he never learned the trick.
An issue of Batman: The Dark Knight lampshades and subverts this. Gordon and Batman are discussing the Mad Hatter's latest scheme, with the discussion eventually ending in this exchange:
Gordon: Hang on. This is where I turn around and you're gone, right?
Batman: No, I'm still here.
(Gordon turns around, and they stare at each other for two panels)
Batwoman, as part and parcel of the entire Bat-package, has on numerous occasions just appeared in a scene without anybody aware of her presence, but it is not a requirement for her like it is with Batman. During her run on Detective Comics she once needed to visit a doctor to have a pair of blood samples analyzed and the script for the scene explicitly instructed that she be drawn just waiting in the office, not trying to surprise the doctor. This time she is standing in plain view, and would be seen by the doctor as soon as the lights were turned on.
Subverted as Bruce Wayne stumbles out the window and falls (very painfully) down a stairwell (hey, it was his first time). Of course, this is before he was actually Batman — once he puts on the suit, he does it flawlessly several times throughout the rest of the movie.
And in another moment:
Scared Thug:WHERE ARE YOU?!? Batman:(hanging upside down behind him) Here. (thug turns around and manages a startled gasp before the screen goes black)
Batman uses this to achieve what basically amounts to a Click Hello without a gun.
The Joker: A little fight in ya, I like that. Batman:(appearing from nowhere) Then you're gonna love me. (fighting ensues)
Lampshaded on the roof of the police station, when Harvey speaks to Batman, turns to Gordon, and then looks back to see Batman having done what he does best. With a shrug, Gordon says, "He does that." This and the dialogue is based on an incident in the mainstream comics, incidentally. Note that Gordon is looking directly at Batman when this happens. To make it more amusing, imagine Gordon was actively complicit in that one. Just imagine the Bat making a shushing motion and giving him a wink before stealthing out to mess with Harvey.
Batman lampshades it in The Dark Knight Rises when Selina Kyle escapes using this while Batman is distracted by a police helicopter.
Another example in Batman (1989), when Batman faces off against Jack Napier in the Acme Chemical factory. Jack Napier bends down to pick up his gun. When he straightens up and looks again, Batman has disappeared. A few seconds later, he reappears out of nowhere.
Actually happens onscreen in Batman Forever. The execution is, unsurprisingly, somewhat disappointing (unless you interpret it as Batman disappearing by literally walking offscreen).
In the film adaptation of Flashpoint Paradox Flash takes off running the second Batman ( Thomas Wayne, not Bruce) turns around to look at something else.
Batman: So that's what it's like to be on the receiving end of that one.
A subversion in Batman: Mask of the Phantasm. Bats tries to pull this on Andrea in her apartment, but she already knows he's there due to the open window. Played straight with the Phantasm, who can arguably pull this stunt off better then even Batman.
"One of these days I'm going to put a bell on his neck..."
In one episode, Batman was able to get away while a roomfull of people were watching him - during a lightning flash. Didn't have time to close the window behind him, but then he seldom bothers with that.
Mad Love borders on Offscreen Teleportation: The Joker falls from a building but lands on a moving train. We see it taking him away from the 'camera' as he laughs and blows a raspberry, presumably at the off-screen Batman - only for Batman to somehow appear directly behind him without the Joker seeing him move.
In Batman Beyond, ("A Touch of Curaré") Commissioner Barbara Gordon tells Batman that he should go, but by the time she turns around, he's already gone, leading her to remark, "Like old times." Another episode has the police wanting to question Batman about Inque (after they shot at both of them); naturally, Batman's nowhere to be found.
In the Episode "Zatanna," Zatanna pulls this on Batman at the end of the episode. That episode also features what might be his first one ever in a flashback - Zatanna cuffs 'John White' to a wall, then comments "If you were a real escape artist, you'd be out of those cuffs and out the door by [turns around]... now"
In Batman Beyond: Return of the Joker, after meeting Terry McGinnis, the adult Tim Drake remarked, "Some things never change".
Also subverted at times, such as when Tim and Barbara notice Terry is around before he gets to the "hi" part. He can get away unnoticed, but it's pretty hard to sneak up on one of the Batchildren.
In Batman: The Brave and the Bold, Batman is able to vanish from the Flash, making him quip that Batman is "the only guy around with a faster getaway than me." One episode reveals that Batman has a very intricate system of tunnels that travel throughout Gotham and are hidden in very weird places. He can go under a fire hydrant and come out of a hot dog cart halfway across the city.
Specifically, when entangled by Plastic Man, Batman throws a smoke bomb and, when the smoke clears, Plastic Man is left in one big knot and Batman is safely in one of his tunnels.
At the beginning of The Cat and the Claw Part II, Batman fades in from the shadows and walks forward, resulting in this exchange:
Contact:(gasps, practically having a heart attack) Batman: You're late. Contact: Can't you ever walk up to someone normal-like?
Subverted once in a Justice League episode. Amada Waller explains why she and Cadmus thinks the Justice League are a menace to the world, causing Batman to just walk out the door, saying nothing.
Naturally, Robin in Young Justice, having inherited his mentor's ability. He usually signals the "hi" with a laugh— Word of God is that, when Batman first taught him how to do it, it was so much fun he just couldn't stop laughing.
Kid Flash: I forgot how much I hate it when he does the ninja thing.
And in "Downtime", Aqualad seems to have picked up this trait from Robin.
Batman is still the master. In the first season finale, a mind-controlled Batman pulls this on Robin twice in the same fight. And the first time, he utilizes Robin's own smoke bomb.
Batgirl and the third Robin both use it, too. Tim apparently can do it with people watching, even!
In a Static Shock that crossed over with Batman, Static does a light flash and disappearance, prompting Batman to remark, "The kid has style."
You can pull this off yourself in Batman: Arkham Asylum. It's difficult (because getting spotted means you'll generally be at a disadvantage in stealth sections), but pull of an inverted takedown, then leap away into the night, and all the remaining bad guys will freak out.
Also from the Batman Arkham Series there is a requirement to get a medal in some of the Predator Challenge maps to appear out of nowhere to scare a terrified enemy. The poor thug nearly has a heart attack as the player pops up out of a floor grate, drops from vantage point, or simply walks behind the thug until they turn around.
This Shortpacked strip ponders what would happen if Gordon simply refused to look away...
Sailor Uranus and Sailor Neptune are fond of suddenly standing or sitting behind the barely five-foot-tall Sailor Moon wherever she goes, and making comments, as if they had been there the whole time.
Usagi herself does this once: Mamoru's just standing on a street corner. A passing truck blocks our view and after it passes... there's Usagi right next to him. Mamoru doesn't notice her until she greets him, startling the hell out of him.
Mamoru often gets in on this too as Tuxedo Mask, combined with Twang Hello. No wonder the fans make him out to be the Japanese equivalent of Batman.
It's also quite common, at least in Fanon, for Sailor Pluto to do this to Usagi as well. There's one particular episode of Stars where she scares the living daylights out of the girls on about three occasions by popping up out of the blue. This episode is famous in fandom. The girls are eating icecream when she appears. Pluto pops up holding a popsicle. She actually pulled that trick twice, the second time was without the popsicle. And it really doesn't help that the episode is freaking hilarious. As well as the first time Pluto appears after the Nehelenia mini-arc.
Hanajima Saki of Fruits Basket does this twice, once to Shigure, Kyo and Yuki, and once to Yuki himself, appearing beside him and saying, "I didn't mean to scare you", causing him to jump out of his seat in terror.
Parodied in Kidou Tenshi Angelic Layer, where Icchan always makes over-the-top, utterly ridiculous entrances out of nowhere and his disappearances are, half the time, caused by either his co-workers calling him to ask where on earth he is or bystanders reporting him as a creepy-looking Mad Scientist hanging around a little girl.
Kaitou Saint Tail, as a phantom thief, has mastered the entrance bit — but always disappears in a flash with streamers, confetti, doves and a bunch of multicoloured balloons.
Bleach: Captains like doing this. Lampshaded in Chapter 99 (Episode 34) by Hinamori. She doesn't realise Byakuya is behind her until he speaks, almost scaring her out of her wits. When he's gone, she doesn't realise Gin is leaning against a wall until he speaks, again almost scaring her out of her wits. When Gin is gone, she doesn't realise Hitsugaya is standing right by her side until he speaks, at which point she explodes.
Hinamori: "That's enough! How come all the captains don't make any sound when they walk?!"
And in a much later chapter, Ichigo shows that he got used to it: after having a stranger suddenly appear in his bedroom where he is having a small party with friends, Ichigo's first reaction is "I don't care who you are, get off my bed." instead of usual surprise.
Legato Bluesummers from Trigun loves doing this to Vash, in order to torment him. This usually happens right before/during/or after something horrific happens, which just cements Legato as horror incarnate.
Ellis pulls this off in El Cazador de la Bruja, instantly teleporting to the bottom of a well to accompany Nadie when she isn't looking. Nadie shouts at this, but quickly goes back to investigating the mysterious whatever, as Ellis has shown other powers prior to this.
Nadeshiko pulls a lot of this in Shugo Chara! Oddly, she/he generally doesn't do so while openly showing her real gender. Within fact, the only time she/he gets close to doing so would be the subversion of her/him tying her/his hair up like Nadeshiko as a surprise answer towards Amu's longing for Nadeshiko to come back. Tsukasa also tends to do this, no matter how far wherever the Guardians may be from him, towards the point where it's surprising that the fandom hasn't pedo - ified him yet.
Kyo Toba, a minor character from Lagoon Engine, does this all the time. In an interesting variation, it's not that he enters or leaves the room, but that he has such a weak presence that people forget he's there almost as soon as they look away. He's also The Faceless for the same reason; even his own immediate family can't remember what his face looks like.
Xellos, from Slayers, frequently uses this trope... and when he doesn't, it's because he's using Offscreen Teleportation or onscreen teleportation instead. Seriously, he never makes entrances or exits normally. He kind of subverts it in that he doesn't need you to look away: he'll teleport anyways.
Azumanga Daioh: Mr. Kimura does this occasionally, notably in the 2nd Year Sports Fest episode. Nobody, not even the audience, sees him come in, but all of a sudden, there he is in the middle of everybody. Almost everyone is pretty startled by his unexpected proximity.
In Tokyo Mew Mew, Kish regularly appears behind Ichigo to hug or try to kiss her.
Lafitte from One Piece surprised everyone in the big marine meeting in the very headquarters when he suddenly appeared in the room. While wearing tapping shoes.
Used in the fourth episode of the anime; Rena is walking down the road a few dozen feet away, Keichi looks away for a second, and then Rena is suddenly standing right behind him... With a cleaver in her hand...
Rena:Found you~, Keiichi...
However, this might be a subversion as it's later revealed that Keichi was suffering from the (extreme) paranoia-inducing disease that drives the plot.
Rika and Hanyuu also disappear when Maebara turns his back in Matsuribayashi-hen. In the middle of a wide open field, after dispensing some prophecies.
Kanon in Umineko no Naku Koro ni tends to do this with his sister Shannon. Later this is completely justified with the reveal that Kanon and Shannon are the same person and so it his appearence and dissappearence is only in her head.
Girls Bravo: Fukuyama does the "hi" part a few times... particularly on the ladies. One instance had him suddenly appear lying on the floor below a skirt-clad Kirie, complimenting her choice in undergarments.
Ranma Saotome does this often in the manga (not the anime).
This is also Hikaru Gosunkugi's main shtick; he's supposedly so banal and socially invisible that other characters (even martial artists) fail to notice him until he makes his presence known. It's exaggerated in the anime, where it looks like he's materializing out of the shadow to startle people.
Alandeilon from Beelzebub does this often, though by far the most disturbing is him appearing from underneath Furuichi's bed!
Played frequently by Gaku of Absolute Boyfriend, who has the habit of popping up at the main character's school, workplace, and even in her home.
In the Harukanaru Toki no Naka de - Hachiyou Shou OAV episode "Omoi no Arika" there's a running gag consisting of Yasuaki suddenly appearing just in the wrong place and time; the Stealth Hi/Bye ability gets lampshaded by Tenma at on point. On one occasion, Yasuaki scares Shimon by popping up from nearby bushes; another scene has him emerging from behind Tenma, prompting the latter to unleash The Scream. Worth noting that the characters are trying to hide something from him, so, of course, most of the time he appears when they're talking about it...
Conway from the anime is particularly fond of combining this trope with Scary Shiny Glasses whenever he pops up. He almost always appears behind Dawn, and she's always startled when it happens.
The eleventh episode of Best Wishes shows that Team Rocket is able to do this as well.
Xerxes Break from Pandora Hearts. It seems that every time the he comes into the screen, unless he's already there and sitting down, he appears from the most random places for the explicit purpose of freaking everyone out. These include an endtable, under a bed, and under a couch.
Mizore from Rosario + Vampire has pulled a Stealth Hi with Tsukune on more than one occasion. She has appeared inside cupboards, in his closet and standing outside an upstairs window, among others.
The Bus Driver often does this, freaking out everybody, even the people with super senses.
Sasami manages to pull this off against Tenchi in her first appearance in Tenchi Universe.
Regularly in Sayonara, Zetsubou-Sensei, Nozomu's devoted Stalker with a Crush, Matoi, will suddenly appear behind him, even if she wasn't anywhere to be seen in the previous frame. The two always have this exchange where Nozomu asks "Were you there the whole time?" and Matoi replies "Yes, always."
Belldandy pulls this on Peorth in Ah! My Goddess when she's trying to ditch the sisters to get alone with Keiichi on a date. Not only does Belldandy show up whenever Peorth turns around, she also just happens to have scored tickets to the next fun activity for them to do.
Renamon of Digimon Tamers has some ninja-esque ability to appear and disappear out of thin air, and talk with her partner at length in the middle of crowded intersections. Takato asks "Where do you come from all the time? Do you just wait around to scare us?"
Nobody ever sees Himari's penguin hat appear on her head in Mawaru-Penguindrum; often it remains unnoticed until "SURVIVALSTRATEGY!!" At least once, it wasn't seen until it made a comment as though it'd been part of the conversation the whole time — cue gawking and, moments later, the aforementioned announcement.
InuYasha: Usually one for the big, flashy entrances that make sure he's the center of attention, Sesshoumaru is very capable of this when he feels like it. At one point, Byakuya is secretly messing with Inuyasha's group from a hiding place and they don't even know he's in the area. He turns to leave, only to find Sesshoumaru standing right behind him.
The main character of Kuroko No Basket has next to no presence, so whenever he talks to someone else, they have no idea where he came from or how long he's been there.
Akemi Homura of Puella Magi Madoka Magica is very good at this, and quite possibly the best example. It's practically her primary mode of transportation, and she has the habit of doing this multiple times per conversation, solely for the sake of showing the other girls just how sorely outclassed they are. At first she seems to be accomplishing this by Flash Step, and then by straight-up teleportation; ultimately, however, it turns out to be a creative application of the power to stop time.
In Puella Magi Madoka Magica The Movie: Rebellion, Sayaka turns the tables and pulls it on Homura of all people. Sayaka covers herself with her cape just as Homura freezes time. She walks up and pulls the cape away, only to find Sayaka is gone. She presumably teleported away or used incredible speed.
In Sakurasou no Pet na Kanojo, Mashiro does this to Sorata in episode 2 when he comments on a beautiful painting he saw in a book. Which turns out to be Mashiro's.
In the anime adaptation of Chuunibyou Demo Koi ga Shitai!, Dekomori comes out of nowhere to slide tackle Shinka while the latter is sitting in art class, then runs back out the door. They aren't even in the same grade (Shinka is in high school while Dekomori is still in middle school).
The Colossal Titan from Attack on Titan quite literally appears out of nowhere and vanishes just as quickly, even though it's a 60m tall monster that appears with no where to hide. Justified, with the revelation that he's a human with the ability to create his massive Titan form out of thin air. With his steam powers creating a Smoke Out and the massive destruction left in his wake, no one notices him sneaking away from the scene.
All of the characters in the Lupin III stories get into the Stealth Hi part. Lupin is the most frequent user of the Stealth Bye part, unfortunately for Inspector Zenigata.
In the Blue Exorcist manga, this happens in chapter 22. Performed by Rin of all people! Could be considered justified by the fact he's a) the Son of Satan and thus has a lot of natural potential and b) Bon just hit a Berserk Button of his that made him recall his foster father's Heroic Sacrifice resulting in a meltdown.
In Astro City, the Confessor, who's something of a Batman Expy, loves to pull this. He even sneaks up behind his sidekick when he's looking at a mirror, which turns out to be a clue...
Escape Artist Yorick pulls a vanishing act on several occasions in Y: The Last Man, much to the annoyance of his bodyguard Agent 355. At the end of the series Agent 355, though claiming this is one trick Yorick hasn't taught her, pulls the same trick to avoid having to say goodbye to him.
Wolverine is also fond of this. Notably, he once pulled it off inside the cockpit of a plane while it was in flight (okay, coming in to land). On a ninja with psychic powers.
Wolverine has an unusual advantage in that he's short, making it easier for him to hide.
Likewise his Opposite-Sex Clone/daughter, X-23. In one case she appears out of nowhere to regroup with Hazmat and Reptil (who hangs a lampshade on it) in Avengers Arena, and her fight against the Facility mooks sent to recapture her in Target X has her taking many of them down Batman-style (before Kimura does it to her). Justified due to extensive training as an assassin, and arguably the genetics she shares with daddy.
Spider-Man's been known to do this too, although it's usually played more comedically.
He often does this by webbing himself to a nearby out-of-sight surface, like an exterior wall.
Spider-Man is on the receiving end in Sensational Spider-Man Volume 2, Issue 40 when a non-descript homeless guy ( The One Above All, aka God) approaches while Peter is giving a vicious beat-down to a city dumpster, without setting off Peter's spider sense.
Vegeta:(Ranting about something) Ginyu: Hey, Vegeta. Vegeta: Hey, Ginyu. (does a Double Take)
One Piece's Fan fiction Website, Ship of fools, Brings us Tarakudo Hunter, who is so quiet that pretty much every time he does anything somebody jumps out of their skin (at one point, he answered a question, and made the person asking jump). Malachi is a more standard case, who tends to appear from nowhere, often entirely unnoticed.
In Weightless, Garrus pulled one on Aria while she was disguising as a dancer. To boost the effect, all the cameras were hacked by Archangel's team, too. Needless to say, Aria wasn't impressed to say the least.
A Shadow Of The Titans: Jade maintains this trait from her canon counterpart, though now it's aided by her ability to hide in shadows. That said, it's been done to her a few times as well, usually by either Gadjo or Jinx.
The Twilight Child: The main character manages to perform one of these, while standing in front of the Cutie Mark Crusaders, who by all accounts haven't turned away from her either. Sweetie Belle even questions how it happened.
Zecora's second appearance involves her managing to perform one of these in a heavily crowded wedding.
The title character manages one on Master Shifu at one point, after being told that he'll have to face Tai Lung. Impressive considering he's a panda, and Shifu is a Kung Fu master with super sensitive hearing who you'd think would've heard him leaving. Shifu's reaction is priceless.
Shifu has this pulled on him again (possibly knowingly) by Tai Lung, when the latter appears before him after a flash of lightning on the steps of the temple.
In Ellie's introduction in Up, she goes from shouting at the far end of the room to directly behind Carl in less than a second.
In Monsters University Squishy does this so often they incorporate it into his scaring technique. The dummy turns around to see him staring at it.
Films — Live-Action
Weekend at Bernie's produced perhaps the best line of the entire two-film series. Bernie's hitman friend Paulie walks into Bernie's house unannounced, and when Bernie turns around and sees him, they have this exchange:
Bernie: OH! Oh, I didn't hear you come in... Paulie: Yup... I'm REAL good at that.
The Landlord and Landlady do an excellent version of this in the film Kung Fu Hustle.
Subverted in the first Scary Movie, when the killer is seen through the window by one of the characters, who looks away for a moment, then looks back and the killer is gone. The audience sees the killer quickly but awkwardly hide behind a tree the moment the character looks away.
Eric Draven, the lead character from the movie The Crow, does this in almost every scene he has with Officer Albrecht, recalling the more famous vigilante/cop duo the quote at the top of the page is taken from. Eventually, they both tire of it:
Albrecht: Are you gonna disappear into thin air again? Eric: ... I thought I'd use your front door.
Spider-Man does it a few times in the first movie. Most notably was when he somehow leapt from the ceiling, out the window and ended up on the underside of the balcony in mere seconds, all without alerting the attention of Norman Osborn, who was in the room at the time and suspected Spider-Man of being there.
He also does it when bringing the body of Osborn back home. Harry looks away for about a second to grab a gun from a drawer, and Spidey is gone when he looks up.
In Spider-Man 2, Doctor Octopus appears to do this after completing a deal with Harry Osborn, taking a sphere full of tritium with him. Though initially surprised, Harry does manage to catch a glimpse of Doc Ock on his way out, moving at a normal (and noisy) pace. Somehow, he managed to move about twenty feet in the span of two seconds without managing to make a sound, before deciding to slow down a bit.
In the third film, MJ walks into her tiny apartment, and walks toward the answering machine, which is near an open window through which light is coming. Then Harry ambushes her, grabs her by the throat, and pushes her up against the wall. Given that James Franco is a shade under six feet, and the character is riding a large hoverboard with glowy bits, one wonders how MJ failed to notice him.
In Serenity, River pulls this off at the beginning of the movie; Simon tries to wake her up, steps way from her to look out a door, turns around, and River is there in his face, without warning. Making this really impressive is that Simon only looks away from River for an instant, during which time she apparently wakes up, climbs out of the chair she's in, and runs all the way across the room. It's apparently genetic; Simon pulls one of these on Mal a few minutes later in the film, jumping him as he comes out of the engine room.
Emelio, the butler of the Mr. Deeds remake, is another master of this. In addition to his ability to be standing in front of an elevator's doors both as they close, and as they open on another floor, he can also instantly move from a stage balcony to the podium to deliver a badass line. One should not underestimate the sneakiness.
In Pandorum, Gallo does this to Peyton several times. Justified, as Gallo is a halluncination of "Peyton"'s younger self.
There's a nice example in the Mel Gibson film The Patriot. Eldest son, Heath Ledger, is watching a disastrous Continental Army defeat from the upper window of an abandoned house when suddenly there's his badass French and Indian War veteran Dad standing calmly beside him leaning on his long rifle.
James Bond does one of these to a Russian soldier in the iconic opening sequence of GoldenEye, complete with Bond One-Liner. This is the first time in the movie the audience sees Bond's face, as played by newcomer Pierce Brosnan.
This trope is used by the titular nanny in Nanny McPhee, mostly on poor old Mr Brown, pretty much daily. Apparently, however, it's a genetic thing to the Brown family, as Simon, the oldest son, walks into Nanny McPhee's empty bedroom, walks by a barren alcove, turns to find her staff resting against a wall, and bangs it, attempting to use the powers Nanny McPhee has been using the entire movie. The moment we hear the staff hit the floor, Nanny McPhee calls out, the camera spins, and Nanny McPhee is seated in a plush chair, with a cup of tea and a book in the empty alcove, with some decor around her.
Jason Bourne is so good at it, he does it subconsciously. The Professor, from the first film, also uses it when he comes to Nikki to pick up the assignment to kill Bourne.
The Avengers (1998). Sir August starts a fight with Steed in a hedge maze. After he knocks Steed's umbrella up in the air, he disappears while Steed is looking up at the umbrella.
The dark-robed, whispering, creepy-looking, angelic, alien-like men in Knowing do this.
DEBS. Lucy Diamond does it twice: first when she takes off after meeting Amy for the first time, and again when she appears in Amy's bedroom.
Spies Like Us. While Emmett is being held by the Tadzhik highway patrol officers, the two KGB Special Branch agents he met earlier suddenly appear inside a room and begin interrogating him.
Alien. While Ripley is inside the computer room talking to Mother, Ash suddenly appears behind her inside the room with no explanation. Note that the door makes a standard "whooshing'' sound, so he couldn't have gotten in that way.
Most slasher movie characters are fond of stealthily saying both Hi and Bye in their special way. Jason Voorhees seemed pretty good at this in the Friday the 13th series, and by the eight film it eventually evolved into the Offscreen Teleportation we know and love.
Scary Movie, of course, mocked this. When Cindy turns away from the killer watching her through the classroom window, he runs and hides behind the nearest tree when she's not looking.
At the end of The Mummy 1999, a bandaged hand grabs Jonathan and he freaks out, thinking it's a mummy, but instead, Ardeth has managed to sneak up on them. On a camel.
The Hospitaller does this to Balian in Kingdom of Heaven. According to Ridley Scott, this is one of several intentional hints that the Hospitaller is not human.
The Good, the Bad and the Ugly. What characters "see" is often dictated by the edges of the frame rather than anything realistic: for instance, at one point Tuco sneaks up on Blondie in an entirely flat landscape, getting close enough to hold a gun to his head before he notices.
In the film version of The Lord of the Rings, Gandalf uses this several times in Bag-End, startling Bilbo Baggins. True to the book, "He comes and goes as he pleases."
Done in the 90s version of A Midsummer Night's Dream. Puck, when summoned by Oberon, always appears just off-screen or otherwise hidden. His teleportations are accompanied by tinkling chimes and Oberon's awareness. Of course, none of this comes as a surprise to anyone, what with faeries and all.
Val Kilmer in Thunderheart is an FBI agent chosen to investigate a crime on a reservation because his father was Sioux and so the higher-ups think the locals will respect him. A few of the locals pull this trope on him as an insult, implying that a real Sioux wouldn't fall for it. That implication is never tested.
In Queen of the Damned, Marius pulls this on David Talbot after taunting him with the usual person-pass-in-front-for-a-second trick. Could be justified with Marius being a vampire and thus a Super Speedster, except that all vampires can usually be still seen as a fast-moving shape. Then again, this could be a tribute to him being so old (he's Roman). Mael also pulls this on Jesse.
Jonah pulls this on the Union officers in Jonah Hex. He suggests they try talking to the body themselves. They do so and when they turn around, Jonah (and his horse) have vanished.
In Congo, a pair of Mizumu appear at the edge of the camp, and Munro tells Peter not to look at them, as they believe their magic keeps them from being seen before revealing themselves. He goes on to say that there are probably twenty more hiding around the camp, truly out of sight.
A variation in Interview with the Vampire, when Louis turns on the light and sits down next to the interviewer in an instant, without the interviewer seeing any movement.
Played repeatedly and for all it's worth by the film adaptation of Dean Koontz's Phantoms, once involving an entire town's population appearing in the street. Probably rates as an invoked example, given that the Ancient Enemy probably learned how to scare the crap out of humans from its victims' memories of horror movies!
Godzilla of all things pulls this off in Godzilla (2014), usually when underwater, though occasionally he uses smoke and debris clouds.
In the Star Wars Expanded Universe, the Noghri. A whole race having trained to hunt and survive on a Death World, their ninja-like abilities are so refined they're often able to sneak up on freaking (and freaked) Jedi.
Jedi and Sith (or, heck, any force user) also has a tendency to do this as well.
General Melvar does a bit of this. Justified as it turns out he A) has a talent for moving quietly, and B) has installed quieter hydraulics throughout the ship to allow him to open doors more quietly and slowly.
Kragar of Steven Brust's Dragaera series is well known for entering a room and not being noticed until he actually speaks. He claims he doesn't do it intentionally; it's just a natural talent (but a handy one for a mob lieutenant). However, it's also why he expects that he'll never be more than a lieutenant; it's not easy to be a mob Boss when people don't notice you.
At one point, a devised plan relied on Kragar's ability to hide out in the open. It actually works, much to the not-surprise of anyone. In one instance, Vlad's wife accidentally sits down on him. In the latest book, Vlad takes great pleasure in finally pulling this on Kragar.
Likewise, the Igors specialize in appearing behind their masters' backs, regardless of how vigilant the master or how coverless the room is. Like most Igor traits, it's hard to be certain whether it is a natural talent, or the result of rigorous training. In Going Postal, Reacher Gilt tests this skill by setting a bear trap down, turning his back to it, and calling for his Igor; the Igor arrives and hands him the now-closed bear trap.
Another Igor example referenced in Going Postal has a character stand with his back to a pit of spikes before calling the Igor. Doesn't explain what Igor did, but they found it very laugh-worthy when the mad scientist forgot and stepped back.
The Psycho for Hire assassin Jonathan Teatime is also skilled at this, being introduced in Hogfather by entering undetected the heavily guarded office of the head of the Assassin's Guild (entering by and hiding in a chimney over alitfireplace) and shortly afterward surprising his mooks in a Bad-Guy Bar by pretending to be a waiter. In the movie adaption, he does that all the time.
Night Watch shows Vetinari training himself in this. He got so good at it that he flunked his stealth class for lack of attendance - despite having never missed a class.
"Where is Havelock?" cried Madam Meserole. "Here," said Vetinari, detaching himself from a shadow by the curtains.
It also has Vimes show himself to be Dangerously Genre Savvy with regards to the Stealth Hi/Bye used by the History Monks — not that it helps. He sees a monk, and then a cart begins to pass in front of him. He drops to the ground, watching the monk's feet. As it's partway past him, his feet are still there. As it's halfway past him, his feet are still there. As it's mostly past him, his feet are still there. When it's completely past him, he's gone.
In Pyramids, when Assassin-trained Teppic was cornered by Dios and a slew of armed guards, he was able to perform this when they looked away for a moment, although it's more like a Flash Step, since he wasn't too far away.
Granny Weatherwax is very good at this, managing to fade into the foreground and occasionally go where ever she'd like while people are keeping their eye out for her.
Inversion. Susan, granddaughter of Death, can make people forget or ignore that she's in the room. To them, it seems she's pulled one of these -if they remember she was there at all.
Bertie Wooster, in P. G. Wodehouse's stories, is perpetually astonished by his valet Jeeves's suddenly being at hand whenever Bertie realizes he needs something. When Bertie is the narrator, he describes it as if Jeeves had a mysterious power of teleportation and/or mind-reading, but the real (implied) explanation is always that Jeeves is streets ahead of his clueless employer.
This is possibly the reason for the Discworld example — Igors are portrayed as a cross between a butler, a surgeon and Frankenstein's monster.
Dexter notes that Astor and Cody have the ability to enter a room without their presence being known until one (usually Astor) speaks.
In David Eddings's Elenium, one of the Knights gets tired of the Goddess Aphrael doing this and asks her to signal next time she appears. So her next manifestation is preceded by a huge trumpet fanfare and holy chorus. Naturally, they ask her to go back to popping up silently.
"People call me 'the big cat,' I know, but among the mountains and rocks the captain is more than a cat. He is a ghost, and that was how men called him in Crete. You will know he is here when he touches you on the shoulder."
Elli Quinn of the Vorkosigan Saga pulls this twice in Ethan of Athos, both times by quietly leaving while everyone else is distracted by something very attention-holding. Fulfills the "audience doesn't see" criteria because the author doesn't describe her departure, just the reaction when somebody turns and looks for her.
Witches and wizards in Harry Potter just love doing this. Causes quite some confusion for Harry in Harry Potter and the Philosopher's Stone when he wonders how Hagrid got to the island to give him his letter and how he left platform 9 3/4 in the time it took Harry to blink. Stealth skills are unnecessary for this, since most wizards can simply teleport.
The rangers in Ranger's Apprentice are well known for this. Halt in particular likes appearing apparently out of nowhere.
In the "between the numbers" entries in the Stephanie Plum series and the Lizzy Tucker spinoff series, Diesel is an expert at this. His cousin Wulf can do a quite good Stealth Hi/Bye if he wants, but prefers a more dramatically pyrotechnic approach.
Bondsmagi of the Gentleman Bastard series are notorious for pulling this, generally much to the surprise and/or irritation of whoever they're dropping in on.
In Rachel Aaron's "Legend of Eli Monpress" series, Nico is quite literally capable of disappearing or appearing with no warning, due to her ability to teleport through shadows. For the most part she only uses it in the presence of her teammates who are aware of her ability and used to it, if still fairly unsettled by it, but will occasionally use it more conspicuously in special cases. At one point, when her emotions overwhelm her to the point of panic, she teleports out of an entire room of onlookers, leaving Eli to talk everyone into believing nothing out of the ordinary had occurred.
Rhaegal, the green-and-bronze dragon from A Song of Ice and Fire, starts getting a rep for pulling these in Meereen. Where Drogon is The Dreaded of the three dragon siblings thanks to his size and strength, Rhaegal is quickly becoming feared for being far too sneaky for comfort. Ordinarily a vocal and highly visible individual, Rhaegal can very quickly find ways of popping up or vanishing where you'd least expect him/her/it to be able to... after dropping the loud act and going into hunting-mode, that is. As Quentyn Martell found, much to his cost.
Angel was fond of doing this in the first season, when he was simply the Mysterious Protector. He kept this power throughout Buffy, and into his own series, on one occasion vanishing out of the back seat of a car with closed doors without seeming to open one. As such, lampshaded with increasing ferocity as the series went on. Hell the lampshade practically hung itself for a while there.
Xander:(referring to Angel, who has just exited stealthily) One of these days I'm going to put a bell on that guy!
Buffy has other examples of this, particularly a subverted scene (somewhat of a trope of its own) when the geek trio attempt a stealth bye with a flashbomb, but the smoke clears to reveal them fiddling with the door ("dude, I thought you said it was unlocked!").
Also in Angel, Connor has a tendency to use this trick, prompting Cordelia to comment, "It must be genetic" (In this particular case, Lamarck was, in fact, correct). Connor actually explains it as using his super speed.
In "Apocalypse, Nowish" referenced above, Connor doesn't say he used super speed, he says "I was just making a sweep..." in other words, he was patrolling stealthily.
In the Angel episode "Somnambulist", it's hinted that Angel doesn't teleport or use super speed, as it shows Kate looking around dumbfounded while the audience sees Angel is just walking away at a normal pace. There are many other examples on his own show where the audience can see Angel has just walked away while other characters clearly seem to think he's vanished. Angel and Connor have some sort of obfuscation, and they have much better reflexes than a normal human, but neither can cover significant distances faster than the human eye can see. Illyria and Glory had super-speed. (Technically, Illyria slowed the world down, but since time is relative, depending on your point if view it's the same thing when they're moving quickly or you're moving slowly.)
In "Epiphany", Lyndsey runs Angel over with his car, then gets out and beats on him with a sledgehammer. He then retrieves a stake from his car... only for Angel to be right behind him and beat him up.
In the series 2 final episode "No Place Like..." it's lampshaded again and Fred is revealed to be capable of doing it, too. (When we first met Fred she had spent some years in a world where, for humans, stealth is a survival skill.)
Gunn: "He's Angel. He does that. How'd she do that?"
Angel: "She's Fred. She does that, too."
Same thing must go for Huntress of Birds of Prey, who manages to pull it on Detective Reese about as often as Bats himself did to Commissioner Gordon.
Alfred did it to him once.
In an episode of Murphy Brown, someone asks a Deep Throat-like informant how he always manages to mysteriously appear out of the shadows, to which he offhandedly explains, "You just stand in a shadow, then step out."
In The Dresden Files, Morgan often pulls this trick on Harry. Late in the first season, he reveals that he actually turns invisible while Harry (and the audience) aren't looking.
Sherlock pulls one of these off in the second episode of season one, The Blind Banker. John and Sarah are at the circus on a date and John is getting their reserved tickets when he is informed that there are three waiting for them, not the two John was expecting. John is confused - until Sherlock pops up out of nowhere behind them, explains that he called back to get the third ticket for himself, introduces himself to Sarah, and promptly walks off offscreen.
John: I've got two reserved for tonight.
Box Office Manager: What name is it?
John: Er... Holmes.
Box Office Manager: Actually, I have three in that name.
John: Oh, no. I think that's an error. He booked two.
Sherlock: (offscreen) And then I phoned back and got one for me as well. (slides onscreen - turns to Sarah.) I'm Sherlock. (slides offscreen)
Done again in "The Sign of Three", when Sherlock vanishes from a park bench in the middle of a conversation with John, without John noticing.
Gibbs does this with the other agents (although he mainly does the Stealth Hi and not the Stealth Bye). It's usually played for a Right Behind Me moment. In one episode Abby puts bubble wrap on the floor across her door as an attempt to warn her when Gibbs is sneaking in. It works, but annoys Gibbs so much that he orders her to get rid of it.
When Gibbs temporarily comes back from his 10-Minute Retirement, he finds Tony, who had been filling in as the team's leader, hiding behind a stairwell while the other agents are talking, eavesdropping with a speakerphone. He tells Gibbs that "you know exactly what I'm doing", and then attempts a Stealth Hi just like Gibbs did as soon as the opportunity arrives. He quickly finds out that Gibbs did not gain his information that way, causing him to remark, "I have much to learn still, master."
Gibbs has a stealth bye pulled on him when he, Kate, and Tony visit Guantanamo. He's giving them orders while reading a newspaper, and they're down the hall arguing over who gets the bedroom with the bathtub. Naturally, Gibbs gets back at them by taking said room.
One particularly memorable moment is, unfortunately, only implied: Abby thinks that Gibbs has forgotten her birthday, and says that she forgives him, prompting Gibbs to tell her to check her desk drawer for his gift, despite her having been in the office all day.
Charles "Chip" Sterling pulls one in his introduction. He attributes it to special shoes, which make him extremely quiet; he turns out to be setting up Tony, so his sneaking skill is appropriate.
On one occasion Tony attempted to outfox Gibbs. When Gibbs failed to appear on cue, Tony was flummoxed, and then Gibbs showed.
Tony and Tim experience a twofer in one episode. They are hiding behind the stairs, observing Gibbs in the bullpen when all of a sudden director Vance appears behind them to ask what they are doing. They make an excuse and watch as the director leaves. Just as Vance closes the door behind him, Gibbs appears right behind them telling them to go back to work.
Hawkeye: Well, Flagg, I guess you've got better things to do — like torturing sheep. Col. Flagg: As a matter of fact, I do. Now everybody close your eyes. BJ: Beg your pardon? Hawkeye: Whaaa? Col. Potter: Close our eyes? Radar: Oh, nonono... Col. Flagg: When I finish a job, nobody sees me leave. BJ:Oh, I forgot. You're the wind. Col. Flagg: I'm either swallowed up by night, or disappear in the mist. It's my trademark. Now close your eyes. Hawkeye: I'd rather close my ears. Col. Flagg:(finally exasperated) If you don't close your eyes, I'm not leaving! Hawkeye & BJ:(both rapidly covering their eyes) Bye! See ya! ''(sound of enthusiastic yelling, followed by the crash of glass; Hawkeye walks over to the office window) Hawkeye: The "wind" just broke his leg.
He succeeds at least once, after being humiliated by Winchester in a tent filled with angry people he turns off the only lamp and is not there when someone manages to turn it back on again. Those present are more impressed by Winchester than by this stunt.
Elaine was menaced by one of these types on an episode of Seinfeld. She dubbed the practice "sidling", and convinced the perpetrator to start carrying Tic-tacs around, letting her know when he was coming or going by the rattling he made. Played with a bit as even though she and and everyone else could HEAR the sidler, he was still functionally invisible until he greeted people.
Subverted in Burn Notice, where Michael explains that it do not involve spy magic, but quick feet and strong fingers, as he is seen hanging from the roof.
Sylar from Heroes does this several times in the first season, both the quick disappearing act and the suddenly appearing from nowhere. Usually Sylar pops up just behind the protagonist's shoulder who only moments before had been looking around an empty room or empty plaza. Bennet and Peter actually speculate in the season finale that Sylar has the power to "hide in plain sight". Given that Sylar has assimilated an unknown number of superpowers, it's not that unlikely.
About Bennet's "hide in plain sight" comment; guess who taps on his shoulder a second later?
He does this in season four out of the back seat of a closed car, reappearing on the top of an apartment building about 100 feet away in less than ten seconds. The writer admits this is 100% Offscreen Teleportation.
Clark Kent does this on occasion, though he usually just speeds away on-screen while everybody is looking away.
Kara picked up the family business and arguably did a better job (read:more off-screen Stealth Byes due to budget cuts).
Green Arrow also pulls this at least once in Season 9 on Cat Grant. When Green Arrow is first introduced, Clark turns from him for two seconds and turns back to find him gone. It's all the more bewildering because Clark doesn't appear to have noticed himself, despite having had super hearing for years by this point.
Lionel Luthor also frequently pulls this off, usually to help reinforce the point that Lionel is sneaky. For instance, Clark or Chloe goes down to the cave and the camera pans around the cave and shows that nobody is there. All of a sudden, a literal second later we hear Lionel's voice saying "Miss Sullivan" or "Clark?" and the character turns around and suddenly Lionel is just there. Lionel managed to do this so often that, given that the show takes place in the DC Universe and the fact that Lionel hangs out with other rich people, one seriously has to wonder if young Bruce Wayne learned this trick by studying Lionel.
Chloe finally gets to pull this trick on Clark when he's stuck in a virtual world. He seems to realise how irritating it is.
In Green Arrow's own series Arrow, he does this a lot, particularly after threatening villains.
At one point he does it out of a moving car in the middle of an empty street.
Christopher Eccleston pulled this off very well in "The Empty Child". When Nancy and her fellow orphans sneak into a dining room while the home's residents are in a bomb-shelter(the ep takes place during the Blitz), Nancy starts a plate around and everyone takes a slice of beef. The Doctor was already sitting at the other end of the table, accepting the plate from the child ahead of him. He later does it again when he follows Nancy to her hideout. She points out that people can't usually do that to her.
For that matter, Nancy herself did it to the Doctor, appearing seemingly out of nowhere to tell him not to answer the phone in the TARDIS (which shouldn't have worked to begin with), and having vanished when he turned around again to question her further about the phone call.
In the same two-parter, Jack disappeared very suddenly... and then, better yet, Rose and the Doctor managed not to notice that they were being teleported.
Jack: Most people notice they've been teleported... You guys are so sweet.
"How dare you?" It was a whisper colder than the wind outside, and it seemed somehow to fill the room. Vettul was back, just behind him. The way she seemed to just appear was uncanny. [...] And she swayed from the room, thump-thumping on her twisted legs.
The Eleventh Doctor does this to Amy in "The Beast Below". He's in the middle of explaining that that time travel is like a nature documentary, they must only observe and never interfere, while the scanner pans over a crying child. Amy questions how hard it must be not to help people, only to realise the scanner now showing the Doctor outside, interfering...
He also does this to Craig in "Closing Time", twice. Once while Craig is trying to tell the lady at the shop that they aren't a couple, and again just before Sophie gets home. Poor Craig.
Neatly subverted in the final episode of Father Ted where a mysterious priest asks about Ted and then vanishes with a little music sting. Ten seconds later he re-appears with the comment "Sorry, I went over there. What did you say?"
LOST's Others are capable of this. A memorable example was Harper's appearance at the beginning of "The Other Woman". The audience was convinced this meant she was actually an apparition, until this was officially debunked.
This happened on Las Vegas, of all places. James Caan's character, Ed Deline, is around a bend in a corridor, holding a gun to the head of someone on the floor. Another character, McCoy, comes along and tells him that the police want him for murder. Ed looks up, and then McCoy turns at the approach of the police. When he, and the camera, turn back, Ed is gone. When the other character reviews the security tape, Ed actually waved through the camera at him, when he wasn't looking. McCoy deletes the recording before we actually see Ed leave. It's implied, but never shown, that Ed escaped through the fire doors behind him.
Kamen Rider Ryuki: Main villain Kanzaki Shirou does this in virtually every scene he's in. He pops in on one of the Riders, tells him to go kill the other Riders, and pops out. Justified as he is utilising a Portal Network that connects all reflective surfaces.
Ted occasionally does this unintentionally, as he puts it: "No one expects me to be anywhere." One episode exaggerates this to the point that he's able to spy on people for a newspaper because people simply don't pay attention to him.
Dr. Cox manages to pull one off. Turk is sitting on a bench near the hospital's parking lot, enjoying a sandwich. A van passes in front of the screen and Dr. Cox is magically sitting next to him. Once he begins talking, Turk is understandably surprised to see him there.
Horatio Caine on CSI: Miami also does this from time to time (mostly the Stealth Hi version), complete with Click Hello when he's sneaking up on the Perp of the Week. Apparently Jerry Bruckheimer didn't think the sunglasses routine and super-serious monotone fulfilled the show's Narm quota.
Played with a bit of a horror aspect in the episode "Bushwhacked". As Mal and Zoe are cleaning out the derilict's cargo bay, the feeling that something is wrong starts to overtake them. They look around the previously empty bay, and find that River has snuck up on them without warning, only this time, she's looking up. The camera pans up, and cue the horror.
Mal pulls one of these on Jubal Early in "Objects in Space", when Early climbs out on top of Serenity and starts for his ship, only to have Mal pop up behind him, rip off a witty one-liner, and hurl him into deep space. More easily justified, as it's space.
Early himself manages to pull it off on Kaylee earlier on, and exploits it for maximum terrifying effect. It helps that Early's appearance would have been completely shocking, since he was a complete stranger and they were in the middle of space (meaning that there would have been no obvious means of him getting on the ship at all).
River pulls off a subtle one in "Safe" when she slips out of the store while Kaylee and Simon have their disagreement. If you watch closely, you can actually see her circling around Kaylee and then vanishing off-screen.
Castiel does this, even when people are looking directly at him. One time Dean was driving in a car, the camera pans around the side of the car (losing sight of the passenger seat in the process) and when it comes to the side of the car, Castiel is sitting calmly shotgun. Dean is considerably startled. Another time, mid-conversation with Dean, he vanishes from the park bench after Dean glances away. It can be assumed that he is flying from place to place (since he's an angel, and the sound of wings and rushing air accompanies his arrival) but visibly he only appears and disappears.
Dean: It's not like Cas lives in my ass. The dude's busy!
Castiel appears behind him
Dean: Cas, get out of my ass!
Castiel: I was never in your...
Crowley turns this into an artform. In fact, he doesn't make any noise at all. When Cas gets upgraded, he starts doing the same thing.
Anna is also shown doing it. At one point appearing in the back of the Winchester car, while Dean's driving.
Anna:(suddenly appearing in the backseat) Hey, guys.
Dean: Ah! (jerks steering wheel, but manages to get the car under control)
Dean: You ever try calling ahead?
Anna: I like the element of surprise.
Of course, beingDean, he immediately starts hitting on her.
On Leverage, Parker ran out on the group in the middle of "The Orphan Job", but tech guy Hardison, having experienced her pulling a stealth bye earlier, tracked her down with the GPS device he sneaked into her shoe should she disappear again. She does this sort of thing all the time.
This is, in fact, a direction note for the series, as noted in the commentary. The audience almost never sees Parker entering or exiting from a room. She just walks into scene once everyone's there.
On Stargate SG-1, Daniel in ascended form does this quite often. In fact, this is the preferred entrance of most ascended beings.
Particularly notable in "Full Circle". Jack, Sam and Jonas need Daniel to appear to help them out, so Jack starts looking round the room calling out to him. The camera follows him, panning round the room. When it gets back to the start, Daniel has appeared, standing right in front of Carter! Naturally, she doesn't notice him until he speaks.
Paris does it to Rory in Gilmore Girls, prompting Rory's "God! You're like the pop-up book from hell!"
Francine is also quite adept.
Subverted in the first episode of How I Met Your Mother, when Marshall and Barney were talking, and Marshall suddenly noticed Barney had disappeared, naturally assuming that Barney was doing another one of his magic tricks(which he used to impress the ladies into bed). Barney pops his head from behind the bathroom doorway and remarks: "I'm taking a leak, dumbass!"
In the finale of Battlestar GalacticaKara Thrace does this in the middle of an open plain when Lee turns away for a moment, proving that she really was killed in Season 3 and is actually some kind of corporeal angel.
Warehouse 13 has the enigmatic Mrs. Frederic, who rarely enters or leaves a room except via this method. Her bodyguard and the Regents (Mark Sheppard, at least) seem capable of doing it as well.
Artie does this once to Claudia in order to catch her disobeying his and the Regents' orders.
An episode of NUMB3RS featured a mysterious government agent checking up on the characters. He had a bad habit of surprising people with a "stealth hi" (his exits were normal), but in a subversion he was also disarmingly cheerful and helpful.
Frank Lemmer from Parker Lewis Can't Lose was quite good at the "bye" part, simply fading into thin air occasionally. At one time this failed when he tried to teleport out of an awkward situation with his current love interest and he just flickered a bit, with a strained facial expression.
Agent LaRoche in The Mentalist is good at sneaking up on people, a useful skill for him to have as an Internal Affairs investigator, since otherwise, the protagonists are likely to try to avoid him.
In The Thick of It, Malcolm Tucker is able to sneak up on people in a glass-walled office. "I'm a shapeshifter!"
On an episode of The West Wing, C.J. manages to sneak into Leo's office behind him without him noticing. After Leo recovers, he says, "You should wear a bell around your neck, you know?"
Happened in The Palace, of all things, with one of the king's senior advisors. Prince George is enjoying a nice bath, when he opens his eyes and jumps, startled. Not only has Sir Iain entered the room without a sound, but he's casually perched on the side of the tub.
In The Big Bang Theory, Sheldon attempts to stay at Raj's apartment in order to avoid a bitter argument between Penny and Leonard. Unfortunately, when he enters, Raj was already in a severe argument regarding leaving for a wedding back in India (citing that he has something important to do for his university as his reason), as well as his parent's implication that he and Howard Wollowitz were a couple ("The closest thing we have to a daughter in law is that Jewish boy Howard"). When Raj turns and angrily asks Sheldon to back him up by telling them that they are just friends, Sheldon was already long gone (obviously because of wanting to run away from their argument).
A running gag in Spooks, despite the show otherwise taking itself quite seriously, is that every Director of a national intelligence agency knows how to do this. Harry in particular seems able to effortlessly break into any building, no matter how difficult it was for the rest of the team.
David Karofsky from Glee started a meme of Suddenly Karofsky due to his tendency to appear seemingly out of nowhere despite his big size and habit of wearing a distinctive red letterman's jacket. It was played for dramatic effect when he was bullying Kurt.
Dang of Canadian ten sitcom Mr Young tends to suddenly appear at random times, mostly when people say his name. He's so good, he can even do this in outer space. In fact, he's so amazing at this that he can do this in two places at the same time.
In Crusade, Galen, the resident techno-mage, did this frequently. In an episode, another techno-mage did the same to him, leading Galen to mutter "Now I know how it feels...".
Pixelface: In "Fool's Gold", Claireparker demonstrates she is an expert at this. Alexia spends most of the episode attempting to prove she is better, without success.
In Revolution, this is the standard method of Big Damn Heroes. In Episode 2-9, "Everyone Says I Love You", Monroe takes the time to lampshade it afterwards.
Monroe: I'm Batman.
Charlie does this in episode 1x02 of By Any Means; disappearing when the DI he is talking to turns to look at the tied-up villain in the boot of a car Charlie has just delivered to him.
Done by Koloth in an episode of Star Trek: Deep Space Nine who sneaks into Odo's office. Odo, being the Chief of Security is understandably disturbed by this, especially since he didn't hear the telltale sound of doors opening. When asked how he got in, Koloth simply introduces himself. When Odo persists that this isn't an answer to his question, Koloth replies that it is. He later explains that he's a Klingon Dahar Master, implying that all Dahar Masters can pull off stunts like that.
Starblazer Adventures, based on the 1970's-80's British science fiction comic book. The Quick Exit and Vanish stunts allow you to do the "Bye" version of this out of combat and during combat, respectively. Using the Vanish stunt requires a dramatic flourish such as a smoke bomb or bright flash.
Maid RPG has a few different versions. As a maid, if you get the power 'Trespass', you can intrude on any scene - including if another character uses the power that makes another dimension solely for them and one other character. The power 'Stalking' makes you completely undetectable while following someone, so you could just appear after following them. And then of course there's 'Teleport'. As a butler, you can also get 'Stalking'. You can also get 'Now You See Him...' which is exactly this, or 'Two As One', which is limited to appearing near the master when in danger. As these have nothing to do with colors, you could even be wearing rainbow tie-die dress or suit while doing this.
Hollow Earth Expedition supplement Mysteries of the Hollow Earth. The Hermit will guide lost travelers to the edge of the Northern twilight region so they can return to the surface world. If after taking a few steps to the south they turn and look back, he will have mysteriously disappeared.
Assassin's Creed allows you to do this when killing guards or targets, but for a non-gameplay example, this is how Altaďr kills one of his targets in the intro video.
Brotherhood also does this with your assassins. When you call them, they will immediately pop out of any nearby hiding space and attack.
A shopkeeper does this to Link, then admits that it's a hobby of his. He doesn't like it much when Link manages to pull this on him.
Tetra likes this one as well. She pulls it once on Link and once on Ganondorf.
Gilgamesh pulls one of these, played for laughs, after the final battle with him in Final Fantasy XII.
Garrett does this to half the people he meets in Thief: Deadly Shadows, including the Big Bad. His mentor manages to pull the same trope over on him once, however, in a hilarious and brilliant inversion.
In Super Smash Bros. Brawl's "Subspace Emissary" mode, Sheik manages a variation of this: instead of disappearing when Fox looks away and looks back, he's suddenly drinking tea (through his mask), without having visibly been offered it. Mundane Utility at its finest.
It should also be noted that the distraction was Princess Peach raising her hand in a "STOP" gesture (in order to stop Zelda/Sheik and Fox from fighting), then offering Fox a cup of tea. When he looks over, Sheik is already drinking a cup, leaving the player to wonder where Peach got the tea first, how Sheik got a cup second. (The scene occurs on top of the enemy airship, which Fox had been attacking until he accidentally almost blasts Peach with his ship's guns, causing Sheik to attack him.) This was a rare example of the distraction being in on it.
He also did it straight in Ocarina of Time on at least one occasion, although he usually blinds Link with a Deku nut as a Distraction.
This is also done by Impa the first time Link meets her. It is suggested that Zelda picked up many of Impa's techniques for use as Shiek.
The Pokémon Trainer does this during Subspace Emissary gameplay, and in large scrolling multiplayer stages. The Trainer himself trails his Pokémon at all times. However, he doesn't follow its movements over Bottomless Pits and similar obstacles. So, the Pokémon can leave the Trainer behind to leap over pits, onto platforms, down elevators... only to find the Trainer inexplicably waiting on the other side.
In The Elder Scrolls IV: Oblivion, Lucien Lachance will sneak up on you when you sleep (and the right conditions are met) to engage your first meeting. When the meeting is over he will use a powerful invisibility spell to hide himself, then leave the room. It's supposed to emulate this trope, but fun things like detection spells, dispelling, and the ability to speak to him tend to ruin the moment.
In a way, it's sort of a subversion — the game's makers could have just had him disappear into thin air, but they decided to do it realistically within their game's rules, and let the player not get "Gordoned" if they're actively trying to avoid it.
Try following him though a door, suddenly he's gone, spooky....
A favourite tactic of serpent thieves in Achaea, who rely on various semi-invisibility tricks to creep into rooms and remain unnoticed while they plant hypnotic suggestions in their victim's mind, only revealing themselves at the last moment to snap their fingers in front of the victim's face and activate the suggestions. One prominent thief likes to play this trope literally, saying "Hi." at the moment of the snap.
One of Alma's favorite tricks in F.E.A.R. Justified, as she's a psychic ghost who can teleport at will.
The aptly-named Houdini Splicers in BioShock are big fans of this one, appearing and disappearing in a cloud of crimson smoke, usually right in front of you or, in your initial encounter with one, right behind you without any warning whatsoever, with hands ablaze.
Actually subverted in that, if you look at water puddles, you can see their feet forming ripples in them.
Played straight with the Lutece's in BioShock Infinite who can appear and disappear at will and sometimes to use shadows caused by flickering lights to cover it.
There's a neat little trick in Metal Gear Solid 2 where you can get an early peek at at a villain who will come in next scene. You can only see him by looking in first-person mode while unarmed (and his face will be partially obscured), and the second time you try it, he'll be gone(cue creepy fanfare).
Played straight in the same game by Mr. X, shortly after giving Raiden a cell phone.
In the ending to Metal Gear 2: Solid Snake, Solid Snake pulled this off on Holly and Campbell, although Campbell implies that this has happened before.
A rather unusual version of this occurs in The World Ends with You. Before Shiki and Neku make a pact by the statue of Haichiko, Joshua is standing right next to Neku. After the cutscene however, he's disappeared.
Government agent Mike Toreno does this to C.J. throughout his missions in GTA: San Andreas. C.J. eventually admits "that guy's like the devil".
In Vagrant Story, the mysterious Sydney does this. Ashley enters an empty room, looks around and sees nothing, then turns toward the door he entered. As he tries to open it, he finds it is inexplicably locked. He turns around again to face the room, and Sydney is there. Their conversation is intriguing. How he got inside or whether he was hiding there the whole time is never explained.
Faith does this in Mirror's Edge when speaking to a detective. The detective looks away briefly when he hears sounds, turns back toward Faith and she is gone. It turns out the sounds he heard were Faith's footsteps as she was vanishing while he was looking at her.
A Gmod addon called The Harmless Companion Cube remains still in plain sight and rewards players who look away with cold, unyielding steel between the shoulders.
Onikage from the Tenchu series is a demonic practicioner of this type of exit. One of his best was following a defeat by Ayame in Wrath of Heaven. The camera pans so that his body is behind her for only a split second, and he is gone. There are a number of other examples from the series. They are Ninja after all.
Played with in Xenosaga episode I, when chaos pulls this off in his first appearance. KOS-MOS re-checks her secondary sensors and sees that yes, he really did just appear out of nowhere. It's just the first clue that this Pretty Boy is far more than he seems.
Hiroshi in Family Project has a tendency to either teleport into the screen or somehow sneak into the attic and from there gain access through to the bathroom ceiling to make sure he is present at any events he feels he should be at. Or at least to cling upsidedown to the bathroom ceiling. It's not exactly clear how he does strange things like this and is chalked up to the fact that he is pretty insane.
In Mana Khemia, Flay got this down pat, startling Vayne several times with his sudden appearance. Nicely averted when Vayne starts to look to where Flay should be at... then he walks through the door.
Sagacious Zu likes to pull this on the party while you're infiltrating the Lotus Assassin Fortress in Jade Empire. He's even good enough to appear from nowhere in Death's Hand's throne room for his Heroic Sacrifice.
Thane will do this during his loyalty mission. He stops to pray in the middle of a well-lit street, and as he finishes the prayer, two people cross in front of him. As soon as they pass, he's gone. The Shadow Broker archives have a video clip of him stepping into a shadow and not coming out the other side.
It seems to be a drell thing, as Feron does the same in the closing cinematic for the Lair of the Shadow Broker DLC during a momentary power outage.
Kasumi's special attack - she Lampshades it with her "Now you see me..."
Shepard himself does this in one scene. Cloaking devices are nice, huh?
In Mass Effect 3, the kid during the Vancouver blitz vanishes without a trace and without making a sound, while inside a rather echoey air vent, in the split second Shepard looks away. The implausibility of this has led to the kid in question appearing regularly in discussions of the Indoctrination Theory.
In Prototype, Alex Mercer seems to be able to teleport in addition to his Person of Mass Destruction and Plague Master status. For example, he manages to get the jump on his ex-boss despite the fact that the morgue security camera confirmed he was still there less than a fraction of a second earlier. Of course, this scares the hell out of everyone else, particularly given that Alex is basically The Thing (1982) save the Antarctic environment and extraterrestrial origins.
Kingdom Hearts is full of them. Riku and Mickey are quite good at it, but the Organization 13 are experts. Xaldin manages to sneak up on Roxas, but the best example has to be Xion and Roxas, who manage to disappear in front of Carpet and Genie... in the middle of a vast open desert... while wearing black robes. That takes skill. Or a black swirling vortex that they use to travel between the worlds...
Unintentional: One of the Sherlock Holmes adventure games, "Sherlock Holmes: Nemesis", wants Watson to always hang around the player (Holmes) so that you can talk to him. Watson doesn't have a walk animation, however. It gets really creepy.
The Anguished One in Devil Survivor 2 likes doing this. He's so good at it that the hero, despite being very much The Stoic, can in one instance get freaked out enough to outright yell at him to cut it out.
Stefan in the Fire Emblem Tellius series consistently joins the party by sneaking onto the battlefield out of nowhere from a space he should have theoretically been visible from (i.e. one that was near but not an edge space). Additionally, in his first info conversation in Path of Radiance, Ike asks him "What the...? Um...who are you? How long have you been a member of my troop?."
Kellam from Awakening has it worse. Despite wearing gigantic shiny armor, he manages to be unseen by everyone. It even takes over a chapter for the characters to notice that he was there from the start, and he has to be re-recruited by the very group he's working with! Apparently he doesn't make any noise when he moves, and he tends to assume conversations are over before they really are, which is why several characters experience him "disappearing" on them as they're speaking to him.
In Atelier Totori, Totori's father is an absolute master of this. In nearly every conversation with him, the characters freak out after his first line and wonder when he showed up. In his case, it's because he has so little presence that even his own daughters often forget he's there.
A character joins your party using this trope in Suikoden III - simply travel through the appropriate area with space in your party, and he'll somehow slip into your ranks with no warning or notification whatsoever.
Ditto the flying squirrels in Suikoden II. While Mukumuku can be recruited in another way, the other four only appear if you wander around a certain area with a space in your party and wait.
Shadow the Hedgehog, of Sonic the Hedgehog fame, pulls off an absolutely awesome subversion in "The Fall" stage of his titular game. The GUN Commander gives him a (completely unjustified) You Killed Maria rant with a gun between Shadow's eyes, then pulls the trigger while the camera is on his face. Cue the camera cutting to behind the Commander - revealing Shadow is gone. And then panning down to reveal Shadow is standing behind the Commander, arms crossed.
Fubar of the Whateley Universe likes to pop in behind people. (Yes, his codename is really Fubar.) Since it's not his real body but an astral projection with telekinesis to give it the appearance of solidity, he can pop in and out whenever he wants.
Ystos from Noob is prone to doing this when using his assassin avatar, frequently creeping up behind other players while they're talking or distracted.
In Dungeons & Dragons, a typical episode would begin with Dungeon Master saying something off-screen, the characters going "Dungeon Master!" and then cutting to him as he gave out a set of cryptic clues and warnings, before either the characters looked away, or he walked behind a tree or rock — and not appearing on the other side.
Bugs Bunny did this all the time. Also Daffy, and in one of his cartoons, The Little Man from the Draft Board.
In Droopy's case, there's often more than one Droopy. Whenever the antagonist wonders how Droopy could be everywhere at once, it turns out there are hundreds of them.
Animaniacs: Yakko, Wakko & Dot, being modern inheritors of Bugs-style cartoon antics, pulled this a lot.
Mr. Director: Hoyl! How'd you... with the going... you were there... but here now... you are... for me to see... how'd you do...
Parodied on Family Guy; Stewie and Brian are standing by the side of the road, and note that they need a quick escape. A truck passes in front of them, and they're gone. Then the camera pans a few feet down the road. Brian and Stewie are standing there.
Brian: It would probably have been a good idea to get on that truck.
Something similar happened in the first Chicken Fight between Ernie and Peter Griffin: Ernie the Giant Chicken manages to escape by Peter unintentionally knocking him onto a truck passing under the overpass, with Peter being shocked at letting the Giant Chicken escape. After waving Peter goodbye, the Giant Chicken smugly turns around, only to express shock at Peter being at the next overpass, who then proceeds to jump onto the truck after him.
In Code Lyoko, the heroes frequently pull this kind of exit on any bystander whenever they hear about a XANA attack. Actually Lampshaded by William about Yumi in "Sabotage":
William: As usual, she couldn't wait to give me the slip...
Parodied in South Park (in The Dark Knight parody episode "TheCoon"), when Cartman's titular alter ego does this to the police repeatedly in each conversation, only to reappear on the other side of the room. Oddly enough, only Da Chief has to look away for him to do this — the rest of the force is still looking at him. Rival hero "Mysterion" plays it straight.
In the Jonny Quest TOS episode "Werewolf of the Timberland", the Indian named White Feather does this several times to Jonny and Hadji.
Parodied on Johnny Bravo. A villain throws a smoke grenade and gives an Evil Laugh, but when the smoke clears, he hasn't moved at all.
Similarly to the Johnny Bravo example above, Mr. Burns once attempted this in The Simpsons, disappearing in a cloud of smoke (laughing maniacally as he did so), in order to avoid paying a sum of money. When the smoke cleared, he had only just managed to get the exit door open and shouted something along the lines of "Oh, fine! Take it!"
The Robot Devil tries this in one episode of Futurama, vanishing in a cloud of smoke in an opera house. Cut to him running up the aisle while everyone is distracted.
Azula pulls this in the first episode of season 2. She waits for Zuko and Iroh by sitting in the shadows of the house they are staying in, and waits several seconds before interrupting their conversation. Given where she was sitting, they should have been able to see her.
Katara also does this in the middle of season 2. On their way to stop the drill from taking down Ba Sing Se, she approaches the guy who's fixing the drill, says a short "Hi", and freezes him so that the others could get the blueprints.
In Teen Titans, Slade combines this with Behind the Black. Terra sees Slade's reflection in a mirror and turns around to face him (and we actually see Terra facing in Slade's direction while his reflection remains motionless in the mirror) but when the camera angle changes to show where Slade should be standing, he's already gone.
Slade also managed to pull this several times in the Season 1 climax, on Robin. You know, the guy who was trained by Batman.
In the American Dad! episode "Failure Is Not a Factory-Installed Option", Stan loses his confidence in his persuasive skills so he goes to see his Sensei. When he returns he enters and exits every scene by pulling a Stealth Hi/Bye, complete with a Sting. When the car salesman still manages to get the best of Stan, he attempts a Stealth Bye, only for the camera to pan over and show him with his head in the mailbox. "Damn! I can't even exit mysteriously anymore!"
Pinkie Pie is able to do this. The strongest examples come from the episode Green Isn't Your Color, where Pinkie is able to appear from an apple cart (with apple in hoof, of course) and from a bucket of sponges smaller than her.
Zecora pulls this off in "The Cutie Pox". After she cures Applebloom's condition, she stays just long enough to offer the filly some sage advice before mysteriously vanishing, much to the amazement of all present.
Trixie... tried. She used a smoke bomb, but everyone could still see her running away once it dispersed - in her second appearance, she tripped.
Storm Hawks: In the penultimate episode, Cyclonis does this a few times with Piper, popping up in front of/behind her. This was some sort of mental telepathic conversation they had, so it overlaps with Mind Rape and Circling Monologue.
In the end of Turtles Forever, the Mirage Comics Turtles pull the bye part on their animated counterparts. 80s Raph approves.
Dawn from Total Drama Revenge of the Island tends to appear and disappear without warning.
The penguins, both in Madagascar and The Penguins of Madagascar. The human antagonist in the tv series adaptation, Mr X., was even stealthier, to the point that even the penguins themselves had to spent half an episode unsuccessfully trying to elude him to go for a swim at a nearby lake after he became a zookeeper. In addition, there was Savio, a suave boa constrictor from the Hoboken Zoo who curbstomped the penguins multiple times, easily avoided their bombs and traps, and surprising them when they least expect it.
Fenwick keeps doing this to Bob Santino in Dogstar. Any time he asks where she is, it can be almost guaranteed that she will be standing right behind him.
Birdman. Although the title hero doesn't normally do this, he does at the end of "Versus the Speed Demon" while the prison warden is telling him what will happen to the re-captured villain.
Magicians of course incorporate this effect in their routines. Even without props and such, it's possible to a degree as people's perceptions can be fooled with much more easily than people believe.
Cats do this all the time, even when they aren't trying as the bodies of all cats are literally designed for stealth thanks to millions of years of evolution, so they do this on pure instinct and is naturally to them as breathing. Putting bells on cats is not as effective as people think, since a competent hunter will simply learn to stalk without ringing the bell. Highly intelligent cats will simply find a way to remove the bell and/or collar entirely, still without making a sound.
Azrael of Gaijin Smash fame was once haunted by a Japanese Schoolgirl who would appear out of nowhere, shout "boobs!", then disappear again.
Most people will have pulled this off or had it pulled off on them purely by accident on at least one occasion. Without special vigilance training most of us are surprisingly oblivious to our surroundings when preoccupied. The increasingly widespread use of handheld electronics with headphones may make this easier to do as the gadgets provide sensory isolation.
Practicing martial arts can make people more efficient, and therefore quieter, at moving around. It results in this trope whether intentional or not.
Vehicles with electric motors can be so quiet, it's been suggested that they be fitted with noisemakers to avoid this trope. Specifically, so people don't get run down crossing the street. Since deaf people have been dealing with that problem for a while and this would not help them we could just learn their technique instead of trying to legislate the problem away. The blind, however, are out of luck in some circumstances.
The fun thing about those legislations: Most of the sound of the car is made by the driving itself, the wheels on the road and so on - so a vehicle with an electric motor would be quieter, but only at low speeds and not by much