Instant Bandages

Characters who suffer Amusing Injuries, or emerge from a Big Ball of Violence, will immediately sport bandages, even if they couldn't possibly have received medical attention. Sometimes, the bandages spontaneously appear in the very next shot, in the immediate aftermath of the blow, as if they had been stamped there by the force of whatever hit the character.

The standard example is a crossed pair of Band-Aids on the head, but the Instant Bandages may be more elaborate. Wrapped gauze dressings covering entire limbs, arm slings, and plaster casts complete with crutches from hammerspace are also fairly common.

Anime and Manga

 * In both the Love Hina manga and OAV, Keitaro is sent to the hospital with a broken leg, much to the surprise of the cast; Keitaro's ability to recover from numerous injuries with Instant Bandages had become a running joke at this point.
 * Maes Hughes manages to pull off this trope after being crushed by a twenty-foot-tall picture of his daughter (don't ask) in one episode of Fullmetal Alchemist (image).
 * Sakaki in Azumanga Daioh seems to have this occur right after most of her attempts to pet cats, all of whom save for one who bite her automatically. After a gang of cats attacked her, she even required a sling for her arm.
 * All over the place in Midori no Hibi. In the pilot, Instant Bandages appear on a cat.
 * One of the characters in Zombie-Loan has the power to summon Instant Bandages for healing. She pays of her loan by selling this service to the other Zombies.
 * Fruits Basket: Kyo gets these after being tripped.
 * Mahou Sensei Negima routinely. When they don't appear, you know that things are getting serious.
 * Done once in Lucky Star. Konata makes a remark about her teacher, Nanako Kuroi. Kuroi hears her, brings a clipboard down on her head, a "THWAK" sound is heard, and the next scene shows Konata with an enormously comical bandage on her head. Oddly enough, the bandage disappears in the next shot.
 * In episode 16, the characters remember Miyuki walking right into a door. After Miyuki opens it and walks in shyly, the bandages disappear in the next shot.
 * In Hidamari Sketch, Miyako gets one after misinterpreting the invitation to their welcoming party as a letter of challenge, and attempting to punish Hiro for the surprise attack; she's hit on the head by Sae. She gets another after being hit by a strong tennis serve by Sae that went into the bamboo grove, and another when she and Yuno are called by Sae, and she jumps the railing to get down. (In the anime, Yuno follows, and gets one, too. Nori gets a couple when sharing a bed with Nazuna, who moves around in her sleep a lot.
 * In Asu no Yoichi episode 3, Tsubasa makes a Face Plant. When she looks up immediately after, her face has manifested a bandage over her nose. A few seconds later, her nose is healed and the bandage is gone. Given that she is a ninja, these things are entirely plausible.
 * In Sekirei, Minato sports a couple after Tsukiumi does a Crash Into Hello on him.

Comic Books

 * Happens all the time in the Franco-Belgian comic Léonard whenever the disciple suffers Amusing Injuries, either at the hands of his sadistic master or through his own incompetence. Sometimes the cat Raoul is shown to bandage him, but most of the time they instantly appear out of thin air. They usually vanish as the scene changes, and sometimes the disciple is shown to have Wolverine-like fast healing with the injuries vanishing gradually as the scene progresses.

Film

 * In Madagascar, the animators/modelers couldn't make Marty's wound to look like an actual wound without making it creepy or disgusting. So they slapped on some bandages instead.
 * This happens to Sam in the live-action movie Transformers Revenge of the Fallen. Apparently Mikaela just happened to have those bandages with her or something. (Of course, this was to cover the actor's actual injury, so it couldn't be smoothly worked into the film.)

Video Games

 * In the game Theme Hospital, broken bones never have to be set. Patients enter already wearing bandages or casts, and the only service the hospital performs is to remove them.
 * This happens to a hill in Super Mario World; the giant bandage is instantly applied upon impact. The shot doesn't cut away at all; there's a small cloud of dust and the bandage is there after. (Presumably the bandage is huge because the impact was caused by a sizable fortress crashing down on the hill).
 * Happens a lot to Mid-Boss in Disgaea, usually after you beat him up.
 * It happens constantly in Loco Roco where bandages just appear instantly on bigger enemies and bosses without even needing ball of violence or next cut.
 * In Punch Out, Everyone will get bandages after the first Knock Down (including you) and will get more after the second one.
 * Tielle from Recettear appears with them on her head anytime she gets hit by a monster.

Western Animation

 * Very frequently done in The Powerpuff Girls
 * Looney Tunes, the Trope Codifier.
 * Just so you are not underwhelmed but what that implies, let us spell it out. Over the past 70 or 80 years a rolling stock of characters have repeatedly used this trope, almost once an episode in some cases, to generates hundreds upons thousands of examples that have probably been the introducer for the concept of triangular bandages for hundreds of millions of children. However, we just can't think of one yet. Try Wile E Coyote and The Road Runner, he gets hurt a lot; it will probably come up.
 * Funnily enough you can now get most of those cartoon characters on band-aids for kids.
 * While it's not instantaneous, Thrust is injured in Transformers Armada and shows up in the next scene with his arm in a sling and his head covered in bandages. In the Decepticon moon base. Where did a robot on the moon get bandages? For that matter, why does a robot have bandages?
 * Apparent quite a few episodes in Courage the Cowardly Dog especially when incurring those injuries himself.

Web Comics

 * Some evil advisors show up in bandages like this Cwen's Quest next we see them after some of them were set on fire. Though at least one of them still suffered from some disfiguring burn marks after the bandages came off.
 * Fey Winds here.