Etiquette Nazi

A character who is egregiously obsessed with manners, politeness and/or (sometimes obscure) etiquette laws, and will do whatever it takes to fix the problem, be it harassment, legal intervention, or violence. The protagonist(s) must stay within this character's rules and expectations so as to not suffer the wrath of etiquette, thus this character becomes a crippling obstacle to the goal which would otherwise be easily attainable.

The intervention doesn't need to be violent, since the protagonist(s) often merely don't want to offend the character for various reasons. And it doesn't always have to be an unreasonable viewpoint, but it always comes out during a situation with a simple solution, which is then pointlessly overcomplicated.

Note: as any modern etiquette book will tell you, the act of being an etiquette nazi is in itself an egregious violation of etiquette. The rules are there to smooth social interaction, not for some stuck-up bastard to use as an excuse to grind it to a screeching halt.

Anime and Manga

 * Kaiketsu Zorori: When Zorori, Ishishi and Noshishi try to help newbie wizard Nelly find the Grun Rod, Noshishi finds a juice dispenser that pours juice into your mouth as long as you stay under it with your mouth open. Naturally taking advantage of this, later he severely has to use the bathroom, and prepares to go behind a bush. Nelly is disgusted by this and demands that he find a bathroom. The only bathroom in the area is a stall in the middle of a bridge, and Noshishi goes into it, only to have the floor fall out, dropping him into the ravine below.

Comedy

 * Stan Freberg's "Old Man River" sketch—he's trying to sing "Old Man River", but keeps getting interrupted by a Moral Guardian who issues on-the-spot revisions to correct perceived instances of ageism, sexism, poor grammar, etc.

Comics

 * Ron Barrett's Politeness Man comic in the National Lampoon magazine. The character constantly got after people for not being polite, often forcing them to act politely even when it made no sense to do so.

Film

 * Serial Mom: Kathleen Turner murders people for various offenses against etiquette, for example beating a woman to death for wearing white after Labor Day.

Literature

 * Mrs. Peacock, in the Clue books (books based off the board game, humorous collections of short mysteries the reader has to solve).

Live Action TV

 * Get Smart: In one episode Maxwell Smart runs across a street while being shot at by KAOS agents, accidentally jaywalking. When he safely arrives at the other side, a police officer demands that he go back and re-cross the street, or else he'll give him a ticket. Naturally, Smart goes back and crosses the street properly, being shot at all the way and all the way back.

Western Animation

 * Two Stupid Dogs: In the first episode where Little Red Riding Hood sees the bigger dog as her granny, she offers the dogs cheesecake, but only letting them eat it within granny's cottage. After finally arriving at the three bears' house (they assume it's granny's house) while the three bears are away, the dogs put the cheesecake up to their mouths when the clock suddenly strikes 9 PM. She takes the cheesecake away from them saying "You can't eat sweets after 9! That's what Granny ALWAYS says!", and makes the dogs go to sleep because 9 PM is bedtime, saying they can have the cheesecake in the morning. When they wake up, the three bears are home.