Gas Mask Longcoat

*The* last word in post-apocalyptic haute couture.

Basically any character that wears a gas mask and, well, a longcoat. Occasionally, there will be a good reason for this, like the character deals with cold weather and/or toxic fumes on a regular basis, but mostly these characters exist because it looks really cool. Trench Coats seem to be the preferred apparel, though other kinds of long coats are acceptable.

Can be one sign of a Post Apocalyptic setting with an unlivable environment. Also common attire for Doom Troops thanks to the dehumanizing and vaguely skeletal/insect-like look of gas masks as well as the implication that Weapons of Mass Destruction are in use by one or more sides. Either way, you are almost certainly living in a Crapsack World if this look is practical or common.

Can overlap with Gas Mask Mooks if said mooks also include trenchcoats in their uniforms. Not to be confused with Badass Longcoat.

Examples of Gas Mask Longcoat include:

Anime and Manga

The 3rd diary holder from Mirai Nikki.
Shingen Kishitani from Durarara!!

Comic Books

The Sandman from Sandman Mystery Theater. Notable in that he also has a hat. Probably the Ur Example in fiction, since he's been sporting the look since 1939.
During the first few arcs of Y: The Last Man, Yorick disguises himself with a gas mask, but phones it in a bit on the coat, wearing a poncho instead.
Dr. Kroenen from Hellboy. He is seen wearing a long coat as part of his Nazi uniform once or twice, but eventually trades it in for a significantly less awesome apron.
Major Maxim, hulking Nazi Super Soldier and main antagonist from the Danger Girl series, wears a similar getup to Kroenen.

Film

The Tatooine-informant alien in Star Wars: A New Hope who ratted out Kenobi and Skywalker to the Stormtroopers in Mos Eisley; he was an alien who looked like he had a gas mask, but he definitely had a long coat.
Kroenen from the film version of Hellboy is dressed in a Nazi uniform, with a black coat and black cap, and a metallic gas mask.
The mooks from Atlantis the Lost Empire, despite the film taking place in 1914 (in real life, gas masks weren't even used until late in the First World War).

Tabletop Games

Imperial trench infantry in Mutant Chronicles, complete with Brodie helmets.
The Death Korps of Krieg from Warhammer 40k are an entire army of this. The Armageddon Steel Legion use this trope as well.
- It should be noted that both are based on real world militaries from the same nation but of different eras. The Death Korps is intended to resemble World War 1 German infantry, whereas the Steel Legion bears more of a resemblance to the later Wermacht uniforms.
Standard uniform of the Deathwatch in Unhallowed Metropolis

Video Games

Fallout: New Vegas: This is the uniform of the NCR Veteran Rangers. Counter to the omnious look, they're the New California Republic's elite force, spreading democracy at gunpoint.
- Tycho from Fallout 1 is described as this if you read his flavor text, but due to the graphical limitations of the time his in-game representation is simply one of the handful of standard NPC sprites.
- In the Honest Hearts DLC, you can find the Desert Ranger combat armor, which is almost exactly like the Ranger armor save for being unaffiliated with a faction and has some distinct markings and writings by it's previous owners.
  - The reason for them looking almost exactly the same is that the NCR adopted the Desert Rangers' (like Tycho, but as mentioned that only showed up in the flavour text) armor for their Veteran Rangers.
- Lonesome Road introduces Riot Armor, which is basically the NCR Veteran Ranger armor from the core game with some stat bonuses and no faction association, as well as the Elite Riot Armor which throws in a minor case of Shoulders of Doom. The overall outfit is slightly more protective but also lighter in weight.

Random Chairman: "Hey baby, you dig these new troopers? The hot fashion is killer robot chic!

- Also, Ulysses wears a coat with the Old World flag on his back as well as a gas mask due to the radiation of The Divide.
Psycho Mantis is this in his first scene in Metal Gear Solid, where all the FOXHOUND members wear coats. He ditches the coat and keeps the gas mask shortly afterward, though.
The First Sons from In Famous. Also crosses over with Gas Mask Mooks.
The original design for the Half Life 2 Combine Mooks featured the civil protection with gasmasks and longcoats. The longcoats were cut, gasmasks were not.
Popular summer wear in Chernobyl.
- However, because the longcoat is the worst armour in the game, don't expect to combine this with Badass Longcoat.
The Corroder from Clock Tower 3 wears a gas mask and a long brown, stained apron that greatly resemble a coat. Justified in that his weapon of choice is a gun that shoots acid.
He lacked the coat initially, but Kabal from Mortal Kombat 3 gained a sleeveless one in Deception and Armageddon.
Silhouette from Destroy All Humans!
One of the possible outfits in Brink, as well as various other Gas Mask Mook looks.
Practically a requirement for characters in Metro 2033.
E.Y.E.: Divine Cybermancy: standard issue uniform for all Federal Cops
Venom troopers in Return to Castle Wolfenstein.
The Storm Troopers in the final mission of Medal of Honor: Airborne.
For the Renaissance-period version of it, the Plague Doctor outfit in Assassin's Creed Brotherhood. Actually has roots in Real Life (see folder below).
The Bogeyman in Silent Hill: Downpour
This is how Zero appears to Junpei when he is kidnapped in Nine Hours, Nine Persons, Nine Doors.

Web Comics

The Captain from Romantically Apocalyptic.
The Gas Mask Mooks (i.e, every single character) in Gone With the Blastwave. This is their army's answer to (apparently) the entire world now being an irradiated wasteland.
If you count a nun's habit as coat, then the satanistic Little Sisters of Belial from Scary Go Round do fit this trope.
The FAN has Captain Nil, though it's technically a cape he's wearing.
Remus introduces Knife Nut Williams as one. He later drops the gas mask and replaces it with a more generic black balaclava.

Web Original

Death's Head, a supervillain with the power to cause spontaneous illness and infection, from the Global Guardians PBEM Universe, wears a World War II-era gas mask, a fedora, and a trenchcoat of his costume.
A-GENT 88 wears this, mostly to help protect people from his ability.
In Fallout: Nuka Break, we meet an NCR Ranger at the end of Episode 6 wearing the armor seen at the top of this page.

Real Life

Many soldiers, particularly German ones, in World War I. Most likely the Trope Maker.
- And for good reason: the coat protected skin against blister agents.
- They weren't called Trenchcoats for nothing.
More primitive versions can be found in the Plague Doctor, who were employed during the Black Plague. The plague doctor's mask possessed glass eyepieces, and the nose was filled with herbs to ward away 'bad air', which was one of the believed causes of the plague at the time. The doctor then wore long thick outer garments to protect them from their surroundings, and carried a cane to interact with things without directly touching them (think that claw thingy the trashman carries). Although there was very little the doctors could actually do for their patients besides taking note of the infected and instigating quarantines, they were paid relatively handsomely for the risk involved in their jobs.