The memetic nature of Fire Emblem Heroes also means that many setups, teams, and characters have special nicknames for them.
- Characters running setups designed to attack four times in one round of combat are referred to using a portmanteau of "quad" and part of their name: e.g. "Quadsuna" (Setsuna) and "Quadelia" (Cordelia).
- "Tiny Hands" for Reinhardt due to how small his hands look in his artwork. There is also "Thundercock" and "The Reinhardt".
- A team with an underlying theme behind it usually gets "[Theme] Emblem" e.g. an all-cavalry team is usually called "Horse Emblem", and a team composed entirely of Camilla and her alts is usually called "Camilla Emblem".
- "Giraffe Mage" for Sophia because of her overly thin and long neck.
- "Nursina", "Healercina", and "Medicina" are names for a skill setup for Lucina that takes advantage of Renewal and Falchion's recovery effect to turn her into a pseudo-healer with Reciprocal Aid. (It works better with Lucina than, say, Marth because Lucina gets Aether for even more self-healing.) Similar builds with other Falchion users follow this trend, such as Medichrom and Medicalm for Chrom and Alm, respectively.
- Alternate versions of characters from seasonal events are often given nicknames to differentiate them from their originals, like "Bunmilla" (Spring Camilla), "Buncina" (Spring Lucina), and "Bridelia" (Bride Cordelia).
- "Reinbow Pulse". It's a specific build of Reinhardt that involves the combination of Moonbow, Quickened Pulse, and his signature Dire Thunder.
- Since colorless units are generally considered to be the worst pool in the game except for a few strong standouts, those standouts are often said to be in "Colorless Hell", since drawing for them will almost always mean spending orbs on a glut of useless Heroes along the way.
- The Black Knight's signature "Black Luna" Special is often referred to as "Eclipse" by fans, both as a reference to the Black Knight's mastery skill from his home games and because it's a cooler-sounding name.
- In a carryover from the fandom for Path of Radiance and Radiant Dawn, the Black Knight gets the nickname "Burger King," due to the top of his helmet vaguely looking like a crown, having the same initials, and the sheer absurdity of comparing him to a fast food chain. As an extension, the one-time 4 dollar orb pack that comes with a free Black Knight is often called "The BK Value Meal".
- The Black Knight is called "Jim Raynor" in some circles due to sharing the same voice (Robert Clotworthy, in a rare case he goes into an anime-ish work) as the aforementioned character from Starcraft and wearing black big suit/armor.
- "Bike" for Brave Ike. It was meant to shorten his name, but it also has the effect of portraying him as a literal bike. Same with "Like" for Legendary Ike, and "Yike"/"Yikes" for Young Ike.
- Lucina's Brave Hero variant is often referred to as "Lancina", to emphasize her classification as a lance user.
- "Ploy Boy" for Arvis, since he effectively has three Ploy skills between his weapon and natural skill set, more than any other character in the game. With the use of the Spd Ploy Sacred Seal, Arvis can run all four ploy skills at once.
- "Bladeblade" for the weapon Laevatein (belonging to the Hero of the same name), due to being a sword with the same special effect as Bladetomes.
- "Psycho Eirika" for the version of her where she wields Gleipnir, due to a meme where she either mugged or outright killed Knoll to rob it from him.
- Spring Kagero is sometimes called "Ninjabbit" because of one of her special activation lines, where she says "Ninjabbit attack!"
- Both of the Fell Robins are officially named "Robin," but the fandom nigh universally refers to both as "Grima" after the being possessing them.
- Reinhardt's sword variant is referred to as "Swordhardt" to differentiate the two.
- "Razzle Dazzle" is the nickname for staff builds that include a combination of Wrathful and Dazzling Staff for the B slot and weapon refine, letting healers take advantage of both of those exclusive skills in a variety of ways.
- There are Voting Gauntlet periods in which the competitors' scores are close enough that neither side is declared weaker or gets a multiplier for the next hour, in which their status is "Same". As this period can potentially stretch on for hours depending on the character match-up (especially during the final round), it has been lovingly dubbed "Same Hell" by some.
- Taking a page from Fate/Grand Order, young Azura is referred to as "Azura Lily", as that game referred to the younger versions of characters as "(Character) Lily".
- Before the announcement in late December 2018 for the update on unit merges for February 2019, "Boon" and "Bane" (from the Avatar creation system of Fire Emblem Fates) were the names called by fans for "Asset" and "Flaw" (from the Avatar creation system from Fire Emblem: Awakening), respectively, with certain Assets having +4 from neutral "Superboons" and -4 from neutral for Flaws "Superbanes". "IV", short for Individual Values from Pokémon, is also used by fans to describe Traits, the combinations of Assets and Flaws, before it was officially named, due to how it similarly works for units in Heroes, as well as "Neutral" for Normalized Traits.
- Immediately upon the reveal of Caineghis's title as "Gallia's Lion King", people called him Mufasa or variations of the name, considering his bulkiness and the fact he's trying to pass his position onto his relative. Even the popular Fire Emblem Heroes Youtuber Phoenixmaster1 calls him this as Youtube's demonetization filter for some reason considers the middle syllable of "Caineghis" to be part of a really racist word.
- "Flierball" for a specific type of defense team for Aether Raids, where players use a full team of fliers units bunched together and buffing each other up with buff Fliers and Drive skills, varied in attack types and weapon effectiveness, and have great mobility due to being able to warp to each other with Flier Formation, Air Orders, and Wings of Mercy.
- "Jelly Skelly" for Hel, Líf, Thrasir, and Ganglöt due of their bodies looking like they are made out of gelatin, exposing their skeletons.
- "Gen X", short for "Generation X", is the nickname for units within a certain BST range during a certain period of their release, with successive "Gen" units have higher BST than their predecessors, usually starting after the release of Chose Your Legends Heroes that year. For example, "Gen 2" 1-ranged units have 5 BST more than their "Gen 1" equivalents.
- "Fishing" is used for the act of checking the score of the matches and spending a Dueling Sword in the process, and quitting out if the score is not high enough in Arena.
- "Rally Trap" is used for a specific strategy in Aether Raids Defense, where a nuker Rallies another unit in attack range of an enemy unit, then a dancer dances them while also removing any debuffs to have the Nuker attack the unit in range instead. "Restore Trap" uses the same strategy, instead the unit is a healer with the Restore+ staff.
- The single use free focus summon on New Heroes and Legendary Remix (and Special, Legendary and Mythic, and Double Special for Feh Pass players) banners after 40 summons on a specific banner has been called "Sparking", named after the spark system in Granblue Fantasy which Heroes uses a similar system, where in Granblue you get a Cerulean Spark for every draw you make, and that within a limited time period players can trade 300 sparks to get a guaranteed drawing of a character they want.
- In the Sept 2020 update, a new item called the Trait Fruit was introduced as a means of changing a unit's assets and flaws. Those are all the official terms, but that didn't stop fans from coming up with different names that coincide with the different ways to refer to assets and flaws, calling these fruit "IVcados" or "Boonanas" instead, or even "Dragonfruits" to match the Dragonflower items which also affect stats.
- Plumeria is often shortened into either "Plum" or "Plums" or "Plumie" or any other sweet-sounding nickname due to her popularity and surprisingly sad backstory that shot her into The Woobie territory.
- Ninja Lyn is usually referred to as Lynja, as a portmanteau of her name and ninja.
- Subsequently, a strategy in Aether Raids Offense in which Ninja Lyn was used for her Galeforce-like Duo skill as well as to act as a Wings of Mercy beacon for other Galeforce units was nicknamed "Lynjaforce".
- "Felix Navidad" for the seasonal version of Felix from the A Miracle Festival event and associated Tempest Trial, named after Jose Feliciano's famous song "Feliz Navidad."
- Eldigan's resplendent version is often called "Heldigan" as a portmanteau of Hel and his name Eldigan, as this version dons a Hel styled outfit.
- Fallen Female Morgan is often called "Momo/Mo-mo" due to being called that by her Regular counterpart in her Forging Bonds scenario.
- On a similar note, Fallen Lilith is sometimes referred to as "Lilith Two" or "Crazy Lilith", due to her Regular counterpart and Sharena nicknaming her.
- Surtr, The Conqueror from Book II is often called Alolan Ganondorf, due to his similar appearance, destructive tendencies, as well as his fire-themes fitting the tropical isles of Alola. There was indeed complaints that a "Surtr Summer Speedo" seasonal alt was not released.
- Fáfnir, the main antagonist of Book V, is sometimes called Galarian Surtr, due to how the two share similar personality traits, but with Niðavellir's mechanical theme replaced with Surtr's fiery motif.
- In a similar way, people also like to call Laevatein Alolan Severa, due to their twintails, similar builds and deadpan expressions.
- "Godswords" is used for any Sword Infantry units that are Lightning Bruisers with powerful skill kits, usually used for heroes such as Ayra, Karla, Catherine, and Legendary and Brave Marth.
- Similarly to Bike and Like above, Fallen Edelgard often gets shortened to Fedelgard. Which often gets shorted to Fedel, as "Edel" is a nickname from Edelgard's home game. "Fedel" then gets warped sometimes to "FedEx," because it's funny, and also she can be really annoying in player vs player modes if you're not expecting her. "Fatalgard" has also gotten some use.
- Upon being revealed in the Book VII Movie, many people have nicknamed Nerþuz "Shiny Freyja", due to her looking very similar to Freyja but with a primarily pink and purple color scheme, compared to Freyja's blue and white color scheme. Fittingly, she's revealed to be Freyja's aunt.
- "Raid Boss" for a unit in a team that is the sole focus for buffs and supports, especially defensively, and is intended to be very difficult to take down.
- Units who haven't received refines for a long time and are highly unlikely to ever receive one are referred to being stuck in the "refine jail". These units include the regular versions of Hector, Reinhardt, Olwen, Ophelia, and Surtr, non-legendary and non-mythic dancers, 3-4 star healers, and every seasonal unit who didn't debut with a perf.
