Nicknaming the Enemy

Soldiers often come up with a name for the enemy that's easy to remember, usually quicker to say than their actual name. Sometimes this is a racial or ethnic slur (and in some cases becomes such a slur); sometimes it's a cultural reference, and sometimes refers to appearance. Doing so is commonly a form of Demonization and has the effect of 'Othering' the enemy, making them seem less human, thus keeping the troops from considering the enemy's humanity, and thus making it easier for the troops to kill them. For that reason, the practice is often encouraged (or at least not discouraged) by the troops' superiors while the war's going on. In science fiction or fantasy settings, this is made even easier when the enemy is not the same species as the troops.

These designations often find a way into propaganda and slogans used to whip up civilian support for the war effort, and continued use of these terms after the war can indicate a person who lived through the war and either adopted the term as a habit of speech or is having trouble moving past those years.

A subtrope of Demonization. Compare to What Measure Is a Mook?, Fantastic Slur, Reporting Names.

Anime and Manga

 * Done in Mobile Suit Gundam, in which the Federation forces were termed "Fedies", and Zeon forces called "Zeeks".

Film

 * Enemy Mine: Dracs are called "lizards" by humans.
 * Blade Runner uses the term "Skinjobs" to refer to Replicants.
 * District 9's "Prawns."
 * In both the 1988 film Alien Nation and the 1989 Fox series that continued the film's storyline, the humanoid alien race is officially referred to as "Newcomers." The epithet "Slag" is used by the bigots who target them.
 * Three Kings had several soldiers discussing which nicknames for the Iraqis were appropriate and which ones were not. One particularly dim-witted soldier complains that he just can't keep it all straight.

Literature:
""The historians can't seem to settle whether to call this one 'The Third Space War' (or the fourth), or whether 'The First Interstellar War' fits it better. We just call it 'The Bug War'.""
 * In Robert Heinlein's Starship Troopers, Humanity's main opponent was officially known as the Arachnids (or Pseudo Arachnids), but the MI called them the Bugs.


 * The other opponent's official name was never mentioned, but the MI called them the Skinnies.
 * In both the book and the movie Black Hawk Down, the Somalians are referred to as "Skinnies" by the Rangers, as they apparently were in real life. While many assume that this refers to the malnutrition of the locals, it's actually a reference to Starship Troopers, which is a popular book among the battalion and required reading at West Point.
 * In Larry Niven and Jerry Pournelle's Footfall, the invading aliens are called the Fithp, but humans call them Snouts because they look like baby elephants with two trunks.
 * In Horatio Hornblower Frenchmen are always referred to as Frogs, and the Spaniards are called Dagos.
 * Honor Harrington has "Manties" (Star Kingdom/Empire of Manticore), "Peeps" (People's Repubic of Haven),"Andies" (Andermani Empire), "Sillies" or "Confeds" (Silesian Confederacy), and "Sollies" (Solarian League).
 * Haven's State Security troopers get called Black Legs, owing to their black uniform trousers.
 * World War Z: United States soldiers referred to the undead as Zack; in the United Kingdom and Europe, they called them Zed.
 * In the Worldwar series, humans are called Big Uglies, the Race are called Lizards.
 * In The Dresden Files, being The Nicknamer, Harry Dresden does this with most of his enemies (and his allies tend to pick them up). Since I Know Your True Name is in effect in this universe this is actually quite a good strategy (some enemies are actually weakened by being referred to by nicknames).
 * Lampshaded with the Denarians, who Harry learned the name of before interacting with them much, and as such, never gave a nickname to (although, even then, their "official" name is "Order of the Blackened Denarius"). When they show back up, he remarks that actually calling them "Denarians" is giving them far too much credit, and asks his allies for suggested nicknames (they go with "Nickelheads").
 * The "Buggers" in Ender's Game.
 * The Mote in God's Eye:
 * The humans nickname the aliens "Moties", since its believed that the alien probe came from the star called "The Mote". Though, it's done not because they're at war, but because they didn't know what the alien's name.
 * "Outies" refers to anyone trying to fight against the Second Empire of Man.
 * In the Star Wars Expanded Universe, the Rebels derisively call Imperials "Bucketheads". More often, they use the term "Imps".

Live Action TV

 * Mash: both North and South Koreans are occasionally called "Gooks" by unsympathetic guest characters.
 * Space: Above and Beyond: The term "Chigs" were used to refer to their alien enemies.
 * Meanwhile, a Silicate agent informs the humans that the Chigs have their own unflattering nickname for the humans, which loosely translates as "Red Stink Creature" - rather close in meaning to what the humans call them. Just as we think the Chigs seem "unnatural" by Terran standards because they have green blood and smell like sulfur, by the standards of what "normal" life forms are on the Chig homeworld, our red blood and non-sulfur smell is disgusting and frightening to them.
 * Battlestar Galactica's remake has the cylons as "Toasters". Human-form cylons are also called "skinjobs".
 * The saurian Scary Dogmatic Aliens of V call themselves "visitors" and are referred to as "lizards".
 * Ultraviolet, a character who is a former soldier refers to Code 5's as "leeches".
 * Most of the dinosaurs in Land of the Lost were given nicknames. The local T-Rex was called Grumpy.
 * Independent-leaning characters in Firefly are known to call Alliance troops "purple-bellies".

Video Games

 * In Ace Combat 5 The Unsung War, the Oseans refer to Yuktobanians as "Yukes".
 * In Halo, the marines call the Elites "split-lips."
 * In fact, most alien names in the Halo universe fit this trope: Grunts, Jackals, Brutes, Elites, Hunters, Buggers, Grubs, and Prophets are all nicknames given by humans to refer to the separate races that compose the coalition of aliens they're at war with. Even their vehicles (Ghosts, Wraiths, Banshees) are nicknamed.
 * Fallout 3s Ghouls refer to humans as "Smoothskins." However, it's not clear whether this is necessarily a slur, as even friendly, sympathetic Ghouls refer to humans as this, sometimes even to their faces. On the other hand, when humans refer to Ghouls as "Zombies," it's definitely' intended to be derogatory.
 * Ditto when Three Dog refers to the Super Mutants as "Frankensteins."
 * In the Wing Commander franchise, expect the humans to call the Kilrathi some variation of Cats or Furballs, while the Kilrathi call the humans "Hairless Apes".
 * In video games featuring a war between the United States and a resurgent Russia, the American soldiers will sometimes use the hypothetical Cold War-era nickname "Ivan" to refer to their enemies.
 * In Killzone the ISA refer to the Helghans as Higs.
 * Star Wars: The Old Republic the Republic forces sometimes call the Sith Empire Imps.

Western Animation

 * In Exo Squad, the Terrans use either "Neos" or "Sapes" for Neosapiens. The first one is PC, the second is a Fantastic Slur, as Marsh points out once.
 * Star Wars: The Clone Wars: the Clone would often call droids as klankers.

Historical/Real Life

 * In World War One, the Germans were often called "Huns" by the Allies.
 * Works made in (or to a lesser extent made later but set in) World War Two refer to Japanese as "Japs" or "Nips" (short for Nipponese), and Germans "Krauts," though some World War One vets may still call them the "Huns;" "Jerry" was another popular term. Calling Italians "Wops" also crops up whenever writers remember the Italians were even in the war. Even officially issued documents like "Know Your PT Boat" (US Navy Bureau of Ships Technical Publication No. 9) did this.
 * The Germans had their own nicknames for the Allies: Tommy (British), Amis (Anglo-American), and Ivan (Russian).
 * Works set in the Vietnam War will contain references to "Charlie" (from the radio callsign for Vietcong, Victor Charlie) in more or less official communiques and to 'gooks' or 'gomers' in the American troops' slang.
 * In the current wars in the middle east, insurgents are referred to as haji's or ragheads by US Army forces, though this is being frowned upon more and more in garrison (at home).