Some characters, most probably unusual ones, are participating in wacky hijinks on their way through the town and decide that they need to go shopping for something, be it mundane, supernatural or just plain crazy. They bust into the store, acting and looking absolutely and completely out of place (and most probably also being totally obnoxious). They get weird looks sent their way, some people sneak out just in case, most customers are stunned with the sheer audacity of the scene.
Cue the Super-Stoic Shopkeeper. He/she will pay absolutely no heed to the hijinks, serve the customers in a composed and orderly fashion, maybe suggest a thing or two the characters might also want, ask whether they prefer to pay with cash or a credit card and basically do anything else they would do for a regular customer.
This happens because perhaps this is a regular occurrence to the shopkeeper, or they've Seen It All and it'd be really hard to surprise them, or maybe they're an Almighty Janitor or someone had them Reassigned to Antarctica. Or maybe they're a disaffected teen who just can't be bothered to care. For whatever reason, anyone and everyone is just a regular customer in their eyes and has to be treated accordingly.
Shopkeepers might not care about who the customer is; see No Hero Discount.
- Borat: One of these visibly restrains himself when Borat asks what type of gun is best for killing Jews. He then suggests a Desert Eagle (an Israeli weapon).
- In RoboCop 3, an elderly hotel receptionist barely glances at the RoboCop, who enters with a naked gun and asks which room the villain stays in. The receptionist answers and gets back to his newspaper.
- The gun shop owner in It reacts perfectly calmly when the Bradley gang (who are topping the nation's most wanted list) just walk into his shop and order thousands of rounds of ammunition. Of course, this being by Stephen King, what happens when they pick up their order is not so pleasant.
- Needful Things: Leland Gaunt doesn't even flinch when his customers are heavily underdressed. Then again the trope applies to him for his own twisted reasons.
- Our Miss Brooks: Mr. Fisher in "Mr. Fisher's Pawn Shop," played by the indomitable Frank Nelson. He doesn't get upset in spite of the wacky hijinks going on all around him.
- Averted in Angel when Darla, after slaughtering most of the occupants of a clothing store, tries to enlist an employee's aid in selecting shoes. Since she does nothing but whimper and try to crawl away, Darla kills her and complains about the service.
- In an episode of Frasier, the same room service guy keeps coming to a hotel room which contains, at various points: Niles and Lilith, Frasier and Lilith, and Niles and Frasier, in various states of undress. They're working through the fallout of Niles sleeping with Lilith. His response to everything is a bemused-but-stoic "OK".
- Korean series 49 Days features Yi Kyung, the Broken Bird who is introduced as a Super-Stoic Shopkeeper getting robbed. She doesn't react to robbery, and even tells them to kill her when she's threatened.
- Comic shop proprietor Stuart in The Big Bang Theory and the way he deals with the parade of ill-adjusted nerds, sociopaths and weirdos who comprise his clientele. Not even Sheldon Cooper fazes him. Much. Although he can be panicked by a pretty girl. (He's had less experience in dealing with pretty girls. Or any sort of girl). And even then, he handles it better than his regular customers.
- Granville (sir David Jason) in sequel series Still Open All Hours. Having inherited the corner shop from the deceased Arkwright, he approaches life with a calm Yorkshire stoicity.
- In Pokémon HeartGold and SoulSilver, the player character spends some time dressed up as a Team Rocket grunt. Every NPC in the city gets new dialogue to reflect this, with most of them expressing either fear or anger. The exceptions are the employees at the local department store, who continue to treat you like a regular customer. One of the other NPCs even lampshades this.
- In ADOM, you can have the weirdest mutations from the corruption of Chaos, but the only one that bothers shopkeepers is the aura that scares away customers. That this one does bother them shows it's probably a deliberate choice to have them ignore the others. Of course, a shop in this game might be halfway down the Caverns of Chaos, so it's only to be expected.
- In Undertale, Burgerpants is a jaded washout working for a narcissistic, delusional robot in a Burger Fool restaurant that doesn't even sell real burgers. If he serves an Omnicidal Maniac player character who's cut a bloody swath through the underground, the extent of his reaction is to complain that he still has to come to work even when everybody's dead and how he "only gets the freaks". He's so sick of his job that even when threatened by the player, he says he can't go to hell as he's "all out of vacation days".
- Atomic Robo: In a flashback, when Doctor Dinosaur (who is, it should be noted, a talking dinosaur) shows up at a science fair with uzis.
Robo: How'd a dinosaur get guns!?
[One Week Ago...]
Alonso: [of "Alonso's Gun Hut"] 'Fraid I'm gonna have t'see some I.D.
Dr. Dinosaur: [holds up a book labeled "Big Book of Dinosaurs", flips it open to a page showing his species]
Alonso: Awright, let's ring y'up.
Dr. Dinosaur: In a perfectly legal manner is how!
- Batman: The Animated Series:
- In the episode "Beware the Creeper", right after being drastically changed by a vat of chemicals and Joker's laughing gas, The Creeper busts into a vintage clothing shop, makes a mess of the place trying to find some clothes to match his new appearance. Clients run and scream. The woman behind the counter says, completely deadpan, "With your skin color, I'd go green." while handing him a pair of underpants. After picking up a few more bits of costume ("How about the boa? Too much?!" "Not on you, baby.") he pays with his credit card.
- In "The Man Who Killed Batman", the bartender remains calm as the place gets turned upside down by a brawl started when another hoodlum decides to pick a fight with Sid (who had supposedly killed Batman) to pump up his reputation. Given that the place is hosting a criminal party to celebrate Sid's triumph, this might be justified as the sort of thing that happens there all the time. The one thing the barkeep does is sneakily slide a glass bowl off a table and onto one man's head, so maybe he enjoys these fights.
- The Simpsons: In The Cartridge Family Homer goes to buy a gun from Bloodbath & Beyond. The clerk remains completely nonplussed, even when Homer repeatedly fires an unloaded handgun in his face and threatens his life for imposing a waiting period.
Homer: I'd kill you if I had my gun!Clerk: Yeah, well, ya don't.
- Steven Universe: In the episode 'Lion 2: The Movie', after Connie and Steven defeat the Robot Shooty Thing, they buy movie tickets with a pink lion and deadly weapon in tow. The ticket-seller is only slightly weirded-out by all this
Steven: Two kids and one lion for Dogcopter 3.Ticket Lady: ...do you have a rewards card?
- The Tick: Most shopkeepers in The City will be either this, or in therapy.
- In the Wander over Yonder episode "The Nice Guy", the cashier at a gas-station convenience store is a snarky teen who is, at most, mildly annoyed by Wander's antics trying to buy Sylvia a Thunder-Blazz.
- In the We Bare Bears episode "Primal", after his brothers go mad with hunger on an ill-planned Horrible Camping Trip, Grizzly hijacks a parked car and drives them to a nearby fast-food restaurant. The cashier at the drive-thru window not only effortlessly translates Panda and Ice Bear's maddened growls into an order, but is completely unfazed by the sight of three bears (two of which are viciously mauling each other in the back seat) paying for the food.
- This is very much a Truth in Television. Those that work in retail often deal with and do business with individuals that are far from the norm. Part of this is professional courtesy, since the individuals are still customers. The other part is from having experience with these kind of customers.