Hadschi Halef Omar Ben Hadschi Abul Abbas Ibn Hadschi Dawuhd al Gossarah, a character in the Orient Cycle books of German author Karl May. He is normally just called Hadschi (Hajji) Halef Omar, but reciting his full name is a shibboleth among readers. If you can't pass the "Hadschi Halef test" you're not a true Karl May fan. The name is long enough for the chorus of the Dschinghis Khan song "Hadschi Halef Omar" to consist of little more.
Golbasto Momarem Evlame Gurdilo Shefin Mully Ully Gue, the Emperor of Lilliput in Gulliver's Travels. It was written when many Real Life rulers had even longer names.
March Upcountry series by John Ringo and David Weber: Prince Roger Ramius Sergei Alexander Chiang MacClintock. (His mother's name is Alexandra Harriet Katryn Griselda Tian MacClintock... the Seventh.)
There is a character in Japanese folklore whose full name is Jugemu-jugemu Gokōnosurikire Kaijarisuigyo-no Suigyōmatsu Unraimatsu Fūraimatsu Kūnerutokoroni-sumutokoro Yaburakōjino-burakōji Paipopaipo-paiponoshūringan Shūringanno-gūrindai Gūrindaino-ponpokopīno-ponpokonāno Chōkyūmeino-chōsuke.note This is where Lakitu gets his Japanese name, "Jugemu" from. Moreover, the Spiny ("Togezou" in Japan) eggs he throws are called "Paipo", another reference to the story.
The full name of the main character in the Mistress Of The Art Of Death novels is Vesuvia Adelia Rachel Ortese Aguilar. Not as long as some of the other examples on this list, but stands out in a world where most people only have a name like Agnes or Mary or Alf or Will.
In J. R. R. Tolkien's Middle-earth (The Lord of the Rings, etc.), the tree-like Ents have a language that to us 'hasty folk' is incredibly long-winded. Entish names are more or less a complete description and history of the individual thing being discussed. Worse yet, due to the phonetics of Ent language (which has a lot of humming), they can't even be transcribed. Tolkien was a linguist; when he wrote that something couldn't be transcribed, he would have had a pretty good idea of how bizarre a language would have to be for that to be the case. However he did offer "a-lalla-lalla-rumba-kamanda-lind-or-burúmë" as a "probably very inaccurate" attempt by the Hobbits to represent a fragment of Entish. This was part of the word for a hill.
So Treebeard's real name would be a description plus biography of his life upto that point in time. This gives some understanding of why Ent-moots take so long. At the time of The Lord of the Rings, Treebeard is the oldest mortal living thing in Middle-earth, and the rest of the Ents aren't too much younger.
Gnomes in the Dragonlance universe have names nearly as long, because, even though they don't live as long as Ents, their names include a description and biography of themselves and every one of their ancestors in recorded history.
In Enid Blyton's The Magic Faraway Tree, Old Wathisname goes to a fortune-teller to ask her to learn the secret of his True Name (Koolamoolitoomarellipowkairollo, or at least, that's how it's pronounced). He tells the others to always request for his true-name, but by the end of the story forgets, because Status Quo Is God.
"Sally" von Humpeding from Thud!. Like other Discworld vampires, Margolotta von Überwald has four pages in the Almanack de Gothic (which parodies the Almanac de Gotha in the same way that Twurp's Peerage parodies Burke's Peerage). The vampire in Monstrous Regiment has to turn over the page while writing down his name to join the army ("but you can just call me Maledict"). It's mentioned in another book that vampires in general tend to acquire very long names "as a means of passing the time."
Apparently this habit carries over even to the ones who've sworn off Uberwaldean naming conventions, as the VP of the Temperance League's Ankh-Morpork mission (according to the relevant Discworld Diary) is named Ms. Jane Mary Betty Pamela Ann Peggy von Jones.
Monstrous Regiment also introduces the nation of Borogravia, which is governed from an old castle at PrinceMarmadukePiotreAlbertHansJosephBernhardtWilhelmsberg. Presumably all of that except the "berg" is the Overly Long Name of the prince whom the place was named after.
The Wee Free Men had a Nac Mac Feegle named "Not-as-big-as-Medium-Sized-Jock-but-bigger-than-Wee-Jock Jock". Pratchett did his usual "wind it to 11" trick on the page he gets introduced, resulting in sentences like ' "No, not Not-as-big-as-Medium-Sized-Jock-but-bigger-than-Wee-Jock, Not-as-big-as-Medium-Sized-Jock-but-bigger-than-Wee-Jock Jock" said Not-as-big-as-Medium-Sized-Jock-but-bigger-than-Wee-Jock Jock. ' It rapidly gets surreal. And hilarious.
C.M.O.T. Dibbler appears many times in the books, and the initials had been understood to stand for his nickname, Cut-me-own-throat Dibbler, until in Making Money his full name was unveiled: Claude Maximillian Overton Transpire Dibbler. So he said anyway, but this is Dibbler (AKA 'throat') we're talking about. It's quite possible he made it up.
Nobby Nobbs is actually called Cecil Wormsborough St John (pronounced sinj'n) Nobbs, which is not just overlong but rather posh for Nobby Nobbs.
It's Nobby. He probably nicked those names off of someone posh.
Occasionally happens by accident in Lancre, where whatever's said at the christening can't be changed. This gives such names as the royals Esmerelda Margaret Note Spelling or My God He's Heavy the First, and the unfortunate commoner "Moocow" Poorchick, a.k.a. James What The Hell's That Cow Doing In Here Poorchick.
One Man Pouring A Bucket Of Water Over two Dogs, or One Man Bucket for short. His slightly older twin wishes he was named Two-Dogs-Fighting.
The city named Heliodeliphilodelphiboschromenos appears in a song (presumably followed by a deep breath) in Eric.
Goblin names are short morose phrases, like Tears Of The Mushroom, Of the Twilight the Darkness or Of The Wind Regretfully Blown (although the latter prefers "Billy"). Only using part of their name is a deadly insult, though some of the more pragmatic ones accept a shorter form, like Of the Chimney the Bones, a goblin constable (when in a fight, "Boney" is a lot more efficient than his real name).
Lady Sybil's full name is Duchess Sybil Deirdre Olgivanna Vimes nee Ramkin.
Tikki Tikki Tembo, an American children's book about "why Chinese people have short names," involves a young boy named... Tikki-tikki-tembo No-sa-rembo Chari-bari-ruchi Pip-peri-pembo note Translation: "The Most Wonderful Thing in the Whole Wide World. The story involves characters forced to say the name multiple times as they report him having fallen into a well. In early versions of the story, it takes so long to organize a rescue that the unfortunate Tikki-tikki-tembo No-sa-rembo Chari-bari-ruchi Pip-peri-pembo drowns. In the more well known children's book, he just barely survives.
This is an adaptation of the story of Jugemu, mentioned above.
In a recorded variant of the work by Paul Wing titled "Long Name No Can Say", the name was Nikki Nikki Tembo No So Rembo Oo Ma Moochi Gamma Gamma Goochi ("Long Name No Can Say" was the nickname everyone called him because of that). In that version, the boy had 6 elder sisters whose 1-syllable names rhymed with "Humph" (the name of the eldest, which was muttered by the father who was disappointed at having a daughter, then repeated for the next 5 ones), and a younger brother named "Yen". The parents also hired a band that would play a silly tune whenever the boy's name was said out loud. And he nearly drowned too, but was rescued in a plan formulated by "Humph" and assisted by Yen. After that it was decided the boy would simply be called "Nikki".
There is a Japanese variant with a name having over 30 parts (in the Russian translation it is given as note Onyudo - Konyudo - Mapiraponyudo - Hiranyudo - Sej-takaponyudo - Harimapobeto - Hejtako - Hejtako - Heme-ta - Kemeta - Ichchiochirika - Chochchorachirika - Chooni-Chooni - Chobikuni - Chotorabucuni - Nagonabicuni - Apoyama - Kopoyama - Amosu - Komosu -Moosu - Moosu - Moosigo - Yasiklapdoni - Temoku - Temoku - Mokuno - Mokuno - Mokudzobo - Tavanchoosuna - Hihidzoeshka)
This does NOT agree with the Japanese variant given in a German collection of Japanese folktales. Due to troper lazyness, have the Korean version instead: Hak-kori-daeji-sandaeji-bawi-doI-soe.
In novels by Iain M. Banks, the interstellar non-empire called The Culture features long names, with references to significant places, symbolic references and group affiliations . For example, Balveda, from Consider Phlebas; Juboal-Rabaroansa Perosteck Alseyn Balveda dam T'seif. She was born on the Rabaroan Orbital, Juboal star system, is currently affiliated with the T'seif estate, was named Perosteck Balveda by her parent(s) and chose Alseyn herself (it's a graceful but fierce avian raptor). By making names this unique, The Culture avoids any confusion. Many of the names Culture ships choose for themselves count as Overly Long Names in their own right, eg the GSV So Much for Subtlety, the ROU All Through with This Niceness and Negotiation Stuff, GSV Anticipation of a New Lover's Arrival, GCU Very Little Gravitas Indeed or ROU Frank Exchange of Views (Psychopath Class).
In Banks's non-culture novel Against a Dark Background, the reverse of this trope—Small Name, Big Ego, perhaps?—is brought into play; the aristocratic main character is named Sharrow. Just Sharrow. When a police officer asks for her full name, she responds... colourfully.
They have an interesting convention that the lower the social class, the more the names. Lampshaded when one character mentions that if Sharrow's cousin had been born with four names instead of one, he'd be a street thief. (This may be a reference to the habit British aristocrats have of using simply the name of their peerage—e.g. Toby Fitzwalter Vere de Vere, Lord Lovaduck, would sign his letters as simply "Lovaduck" without any of his given names, or even the title "Lord.")
Ue Mistake Not My Current State of Joshing Gentle Peevishness for the Awesome and Terrible Majesty of the Towering Seas of Ire That Are Themselves the Milquetoast Shallows Fringing My Vast Oceans of Wrath (Known as Ue Mistake Not... for short).
Outside the Culture, the main character in Whit, or Isis Among the Unsaved is The Blessed Very Reverend Gaia-Marie Isis Saraswati Minerva Mirza Whit of Luskentyre, Beloved Elect of God III. Her grandfather, the founder of Luskentyrism, also has an overly long name, owing to his habit of adding middle names from various religious sources whenever he feels like it.
Pippi Longstocking: Pippilotta Delicatessa Windowshade Mackrelmint Ephraimsdaughter Longstocking. Or her original Swedish name, Pippilotta Viktualia Rullgardina Krusmynta Efraimsdotter Långstrump.
Star Surgeon by Alan Edward Nourse has the character Dal Timgar, whose full name is unpronounceable to humans.
Dal took a deep breath and began to give his full Garvian name. It was untranslatable and unpronounceable to Earthmen, who could not reproduce the sequence of pops and whistles that made up the Garvian tongue. The doctors listened, blinking, as the complex family structure and ancestry which entered into every Garvian's full name continued to roll from Dal's lips. He was entering into the third generation removed of his father's lineage when Doctor Tanner held up his hand.
Oscar Zoroaster Phadrig Isaac Norman Henkle Emmannuel Ambroise Diggs, more commonly known as The Wizard of Oz. (Oz, because the rest of his name spells PINHEAD.)
In the Polish translation he gets even more names. The initials after "O.Z." actually spell three words.
From the works of Robert Rankin we have Hugo Artemis Solon Saturnicus Reginald Arthur Rune, the Guru's Guru, the Logos of the Eon, the Hokus Bloke, the Perfect Master, the Mumbo Gumshoe, the Cosmic Dick, the Reinventor of the Ocarina, the Lad Himself (but you may call me "Master").
Used a few times in Diane Duane's Young Wizards books mostly in the Foreign Sounding Gibberish sense, as most possessors of odd names here are not human, such as Khairelikoblepharehglukumeilichephreidosd'enagouni, better known as "Fred" (who is a white hole and therefore seems to be translating his name from various forms of radiation); there's also the great white shark ed'Rastekeresket t'k Gh'shestaesteh, whose name gets shortened to Ed, and aliens Roshaun ke Nelaid am Seriv am Teliuyve am Meseph am Veliz am Terianst am det Nuiiliat (who is royalty, and his name therefore denotes lineage), and Filifermanhathrhumneits'elhhessaifnth, or "Filif" (an alien tree). One can conclude that Diane Duane is rather fond of overly long names to establish alien-ness rather than to invoke comedy—though the idea of a 100-foot-long great white answering to "Ed" is rather comedic.
Oddly Fred's full name is a slightly-off transliteration of a line from the Homeric Hymn to Aphrodite (chair' helikoblephare, glukumeiliche: dos d' en agoni). Roshaun's full name was actually quite a bit longer; that was what he considered an appropriately respectful nickname.
She also loves doing this in her Star Trek novels, especially concerning Romulans — sorry, Rihannsu. The Romulan Way features a Romulan Commander named Ael i-Mhiessan t'Rllaillieu, and a Federation agent going by the name Arrhae ir-Mnaeha t'Khellian. To make things even worse, the poor woman's Human name is Terise Haleakala-LoBrutto. And now my fingers have cramped up.
In the Wild Cards novels, the alien who tries to stop the release of Xenovirus Takis-A on Earth has a name that begins with Prince Tisianne brant Ts'ara sek Halima sek Ragnar sek Omian of House Ilkazam (and that's just his first name; his full name would list his genealogy for the last thousand generations). The American scientists and military men he makes first contact with are endlessly corrected on how it's said, and mispronouncing it is quite the insult. So he is given the much-simpler nickname Dr. Tachyon.
In the afterword to 3001, Arthur C. Clarke admits to rifling through a Sri Lankan phonebook to find the name "Thirugnanasampanthamoorthy". (The character so named comes up with the idea of infecting the Monolith with a computer virus.) It's rather a short name by Sri Lankan standards.
Also, in 2010, it is revealed that the full name of Dr. Chandra, who programmed the HAL 9000 computer, is Dr. Sivasubramanian Chandrasegarampillai.
The character Jeronimo, colloquially known as "El Desamperado" in Neal Stephenson's The Baroque Cycle, Book 4: Bonanza, has the full name and title of Excellentissimo Domino Jeronimo Alejandro PeÃ±asco de Halcones Quinto, Marchioni de Azuaga et de Hornachos, Comiti de Llerena, Barcarrota, et de Jerez de los Caballeros, Vicecomite de Llera, EntrÃn Alto y Bajo, et de Cabeza del Buey, Baroni de Barrax, Baza, Nerva, Jadraque, Brazatortas, Gargantiel, et de Val de las Muertas, Domino Domus de Atalaya, Ordinis Equestris Calatravae Beneficiario de la Fresneda. This is Truth in Television, or close: many Spanish nobleman did have ridiculously long names, and much of it is actually titles of nobility: if you strip out all the Barons of this and Counts of that, you can figure out that he has exactly two given names as we'd understand the term. (Jeronimo and Alejandro.)
The heroine of The Princess Diaries (the books, not The Film of the Book) learns her full name is Amelia Migonette Thermopolis Grimaldi Renaldo. As opposed to just Mia Thermopolis, which some would consider bad enough.
Francisco Domingo Carlos Andres Sebastian d'Anconia, the largest copper magnate in the world of Ayn Rand's Atlas Shrugged. At one point a guard asks him his name; he replies, "There isn't time to tell you."
Word of God is that the character's full name is "Wilthurio Longbarrow Sackfirth Toxophola Fedlric Fritillary Wilfrand Hurdleframe Longarrow Leawelt Pugnacio Cinnabar Hillwether Jodrellio", hence why he's known as "Jodd".
Every hare has one of these. Such as Bellscut Oglecrop Obrathon Ragglewaithe Audube Baggscut—shortened to Boorab—from The Taggerung.
Cap'n Tramun Josiah Cuttlefish Clogg probably comes under this heading, particularly by the standards of vermin, who usually have one-word three-syllable names at most (which are all nicknames anyway).
Then there's the Painted Ones' leader, Shavvakamalla.
In the Liaden Universe stories of Steve Miller and Sharon Lee there's an alien race among whom each individual's name is not merely a reference label but a complete description of the individual (they're extremely long-lived, and like the Ents have never seen the value of shortcuts). The individual who most often appears in the stories is introduced as "Twelfth Shell Fifth Hatched Knife Clan of Middle River's Spring Spawn of Farmer Greentrees of the Spear-makers Den, The Edger"—and that's the ultra-condensed version he uses on human paperwork; his full name, we're told, takes nearly twelve hours to speak. Fortunately for the characters (and the reader), he lets his human friends get away with just "Edger".
Alan Dean Foster's novel Spellsinger features "Caspar di Lorca di l'Omollia di los Enansas Giterxos", more usually known as "Caz". A city councilor in the sequel goes by the name of Millevoddevareen. Ironically, his associate Mudge accuses the hero, Jonathan Thomas Meriweather, of having an excessively long name and insists on calling him "Jon-Tom".
Also by Foster, The End of the Matter features a goofy-looking mad alien that claims to be named Abalamahalamatandra. In Sentenced to Prism, the protagonist meets a caterpillar-like creature named A Surface of Fine Azure-Tinted Reflection With Pyroxin Dendritic Inclusions.
The Hollows has Ptah Ammon Fineas Horton Madison Parker Piscary. They just call him Piscary.
The title character of Christopher Stasheff's The Warlock in Spite of Himself is Rod Gallowglass, "born Rodney d'Armand (he had five middle names, but they make dull reading)...."
In Andre Norton's early novel The Prince Commands there's "Michael Karl Johann Stefan Rene Eric Marie, Prince and Lord of Rein, First Lord of the Kingdom, Duke of Casnov, Count of Urnt, Baron of Kelive," (plus several others, including colonelcy of three different units), newly informed of his royal heritage and usually referred to or addressed simply as "Michael Karl." The family name, although not included in that recitation, is Karloff. (Some of his titles may have gone away when it turned out his cousin the Crown Prince wasn't dead after all. But then, he might have gotten them back after the Crown Prince became King.)
Aximili-Esgarrouth-Isthill, an Andalite from Animorphs, usually shortened to Ax by his human compatriots. All the Andalites have a similar three-part name, which apparently have a first name, family name (from either the mother or father's middle name) and a third name.
Ketran names as well. Toomin/The Ellimist was formally known as Azure Level, Seven Spar, Extension Two, Down-Messenger, Forty-one (actually kind of an address, his place on the giant crystals in the sky.)
Voltaire's Candide had governor Don Fernando d'Ibaraa y Figueora y Mascarenes y Lampourdos y Souza.
The fun is not confined to the Spanish language: an early chapter is set in the quaint German village of Waldberghof-Trabk-Dickdorf.
While not as impressive as some of the other names in this list, mention should still be made of Sir Darian Firkin k'Vala k'Valdemar from the Heralds of Valdemar series. Technically he could also probably add "of Ghost Cat" to the end of that, though nobody ever uses that particular one. He actually grew up with the far more reasonable name Darian Firkin, it just got a bit extended over time.
In Andrzei Sapkowski The Witcher novels anyone who has any connection to the elves (like Nilfgaardian nobility, Nilfgaard Empire assimilating indigenous Elven population, instead of persecuting it like Nordling kingdoms) or vampires sport names at least a full line long. Other race aren't that big on the matter.
One of the characters in Raymond Queneau's The Blue Flowers is named Joachim Olinde Anastase Crepinien Honorat Irenee Mederic, whose initials spell out his first name.
From Isaac Asimov's Foundation: people from the planet Gaia start with short names, but add syllables as they grow older. They usually adopt one-syllable names for everyday use. Dom, for example, whose full name is 253 syllables long, only reminds himself of his full name once a year on his birthday.
The Chiss race have longish names which are contracted to a daily-use shorter version, the "core name." People need permission to use those, though—it's like going on a First-Name Basis. Mitth'raw'nuruodo, rather hard to say for most people, first courteously and then with more condescension allowed humans to call him Thrawn.
Yoda: Dark Rendezvous has the young Padawan Tallisibeth Enwandung-Esterhazy. She goes by Scout.
In Tales of the Bounty Hunters, we have Hekis Durumm Perdo Kolokk Baldikarr Thun, one of the few humans on Mechis III, who added a new, grandiose title to his name whenever he felt his superiors didn't appreciate him. So not only does he have a Overly Long Name, but it's self-inflicted at that. IG-88 had his personal servant droid put a blaster bolt through his head as part of the take over of Mechis III, putting him out of everyone's misery.
The Witchfinders in Good Omens tend to have ridiculously long names like Praise-Him-All-Ye-Works-Of-The-Lord-And-Flye-Fornication Smith and Ye-Shall-Not-Eat-Any-Living-Thing-With-The-Blood-Neither-Shall-Ye-Use-Enchantment-Nor-Observe-Times Dalrymple. Apparently this is an exaggeration of what used to be a common naming practice.
Also, the name they call the Antichrist by in the hospital sequence. Played for Laughs here, and especially funny when it's repeated several times across a page.
Currently she is being handed a golden-haired male baby we will call the Adversary, Destroyer of Kings, Angel of the Bottomless Pit, Great Beast that is called Dragon, Prince of This World, Father of Lies, Spawn of Satan, and Lord of Darkness.
Funnier because he's being contrasted in that paragraph with two babies referred to only as Baby A and Baby B.
The heroine of The Ordinary Princess is named "Amethyst Alexandra Augusta Araminta Adelaide Aurelia Anne". She prefers to go by "Amy".
Clennen Mendakersson in The Dalemark Quartet is self-admittedly fond of long names, and thinks his own and his wife's are too short. So he made up for it with his children and his horse: Dastgandlen Handagner Clennensson, Cennoreth Manaliabrid Clennensdaughter, Osfameron Tanamoril Clennensson, and Barangarolob. Dagner, Brid, Moril, and Olob for short.
The Bible has Isaiah's son Maher-shalal-hash-baz, which is both the longest name and word in the Bible. And somehow there's an American actor with that name (which has since shortened the thing to "Mahershala").
In Larry Niven's Ringworld novels, the City Builders and their client races such as the Machine People have names five to six syllables long. Examples include Halrloprillalar, Valavirgillin, Laliskareerlyar, Arrivercompanth, Harkabeeparolyn and Kawaresksenjajok.
At one point, Aral introduces himself as Prime Minister Admiral Count Aral Vorkosigan.
From Lord Vorpatril's Alliance: Tej, whose full name is Akuti Tejaswini Jyoti ghem Estif Arqua Vorpatril. Her father found a book entitled Ten Thousand Authentic Ethnic Baby Names From Old Earth, Their Meanings and Geographical Origins and was apparently attempting to use as many of them as possible on his children. They have half a dozen each, which they boiled down to a nickname.
The Princess from the Myth Adventures short story "Myth-ter Right" is named Gloriannamarjolie. That's just her first name, as was selected by her father, King Henryarthurjon.
The Stormlight Archive has the character known as "Rock" whose real name is "Numuhukumakiaki'aialumamor", which apparently is a poem in his native language about a rock his father found just before his birth.
This is the premise of the book Turtle Knows Your Name where the main character's name is Upsilimana Tumpalerado and everyone makes fun of him for it; it is later reveled his grandma's name is Mapaseedo Jackalindy Eye Pie Tackarindy.
In Robin McKinley's Sleeping Beauty retellingSpindles End, the princess's full name is Casta Albinia Allegra Dove Minerva Fidelia Aletta Blythe Domnia Delicia Aurelia Grace Isabel Griselda Gwyneth Pearl Ruby Coral Lily Iris Briar Rose. Evidently this isn't an unusually long name for a royal—at least, no one ever remarks on its length.
In Eric Linklater's The Pirates in the Deep Green Sea, octopi have very long names. Culliferdontofoscofoliopolydesteropouf reluctantly allows the other protagonists to call him Cully, while pointing out that it's a very short name for an octopus.
His Excellency Shri Katarnak Kala Kaloota Kawa Kaw Kaw, a white crow who becomes an Evil Overlord in the Crow Chronicles.
In Warrior Cats, all cats of the Tribe of Rushing Water have overly long names, like Brook Where Small Fish Swim or Pebble That Rolls Down Mountain or Teller Of The Pointed Stones. They just go by shortened versions of their names, such as Brook or Stoneteller.
The Sandra Boynton book 15 Pets had the turtle have one of these, while the fourteen other animals are simply named Bob.
The Latlans in Andraste all have obnoxiously long names. One of the protagonists is named Arcassyle Noveclyde Pulynn Argenaddynn, Syrakkddnnson. He goes by 'Elvin'.
In Tales of Kolmar, the Kantri all have lengthy truenames known to very few and rarely spoken, short usenames known by all, and slightly longer usenames used by close friends. Their king's truename is Khordeshkhistriakhor, Akhor to most, Akhorishaan to close friends. The human Lanen can't pronounce his usename properly and calls him Akor. When Akhor becomes human, he finds his old truename no longer applies and picks a new one - Varien Kantriakor rash-Gedri, Kadreshi naLanen, which he lampshades as being a bit long. Varien the Changed One, for short.
The formal name of the title character in Mark Twain's "The Stolen White Elephant" is Hassan Ben Ali Ben Selim Abdallah Mohammed Moisé Alhammal Jamsetjejeebhoy Dhuleep Sultan Ebu Bhudpoor. Its nickname is "Jumbo."
In Robert Jordan's Wheel of Time wolves are introduced with very simple names such as Two Moons, or Dapple or Hopper. Two Moons actual name is more a mixture of scents and images that combine to actually mean "a night shrouded pool, smooth as ice in the instant before a breeze stirred, with a tang of autumn in the air, and one moon hanging full in the sky and another reflected perfectly on the water so that it was difficult to tell which was real. And that is cutting it to the bone."
There's a god from the Dragaera novels named Tristangrascalaticrunagore, although even his fellow-deities generally call him Tri'nagore for short.
The original names of the seventeen great weapons tend to be this, like Magical-Wand-That-Creates-Death-in-the-Form-of-a-Black-Sword. The current wielders all use shortened names (for instance, the previous name gets shortened to "Blackwand").
The Western Hemisphere Union ships in Allen Steele's Coyote trilogy had names that were long paeans to their revolutionary state ideology/system, Social Collectivism. An example is WHSS Seeking Glorious Destiny Among the Stars for the Greater Good of Social Collectivism. Even the captains of these ships, and Union bigwigs, would refer to these ships by truncated names, such as the Glorious Destiny for the above example.
In Charles Williams' War In Heaven, one character introduces himself as "Aubrey Duncan Peregrine Mary de Lisle D'Estrange, Duke of the North Ridings, Marquess of Craigmullen and Plessing, Count of the Holy Roman Empire, Knight of the Cape and Sword, and several other ridiculous fantasies."
The Queen of Manticore, Elizabeth III, aka Elizabeth Adrienne Samantha Annette Winton. She goes by "Beth" to her family and closest friends, "Elizabeth" to the rest of her inner circle, and "Your Majesty" to everyone else.
Honor Harrington's best friend (and the Queen's first cousin), Gloria Michelle Samantha Evelyn Henke. She goes by "Mike".
Henke's flag lieutenant, Gervais Winton Erwin Neville Archer. He goes by "Gwen".
Honor's mother, Allison Carmena Elena Inéz Regina Benton-Ramirez y Chou Harrington. She goes by "Allison", "Dr. Harrington", or—to her husband and brother—"Alley". And she'd really rather ditch everything between "Allison" and "Harrington" anyway...
Honor's sister is Faith Katherine Miranda Honor Stephanie Harrington. Her brother was a bit luckier, and is "only" James Andrew Benjamin Harrington.
Weber's another series, Safehold, does the same, with added bonus of My Nayme Is. For example, one of main characters is Cayleb Zhan Haarahld Bryahn Ahrmahk note Duke of Ahrmahk, Prince of Tellesberg, Prince Protector of the Realm, King and Emperor of Charis, although he's generally called just Cayleb or Cayleb II. His daughter is Alahnah Zhanayt Naimu Ahrmahk, and his wife's full name(s) are Sharleyan Alahnah Zhenyfyr Ahlyssa Tayt Ahrmahk.
There's also fresh and revamped Harchongese army, going by the name Mighty Host Of God And The Archangels.
Dragon In Distress has Princess Florinara Tansimasa Qasilava Delagordune, who insists you call her by her full name.
Zigzagged in the SF short story "Traveller's Rest" by David I. Masson. The hero's name "Hadolarisóndamo", a.k.a. vsq 389 mld 194 rv 27 xn 3 is not that long, but in the beginning and end of the novel it gets shortened just to "H" due to the time gradient.
In Golden Dawn, the trapped angel's name is Midwinter Sunrise When The Sun's Rays Touch The Snow-covered Mountains And Reflect The Pale, Golden Light. More of a description, really.
In Vampire Academy, Lissa's full name is a minor example: Vasilisa Sabina Rhea Dragomir.
Mr Gum has a spectacular example in its nine-year-old heroine Polly, whose real name is Jammy Grammy Lammy F'Huppa F'Huppa Berlin Stereo Eo Eo Lebb C'Yepp Nermonica Le Straypek De Grespin De Crespin De Spespin De Vespin De Whoop De Loop De Brunkle Merry Christmas Lenoir.
While we never see the full name of Mina and Jonathan's son in Dracula, it's mentioned that he's named after all of those who participated in the adventure, suggesting very strongly that this trope applies.
The Hungarian political novel Journey of Tarimenes has "Bangocibumbujpulujhurculujbüszkülüjkikiriposzidoszi", the personification of aristocracy.
In the Zachary Nixon Johnson series, the Thompson family butler is named Wintercrescenhavenshivershamshawjamison.
People from the nation of Herun in The Riddle Master Trilogy typically have very long, elaborate, difficult-to-pronounce names, though they typically only use them in formal situations - a syllable or two will suffice among friends. Hence, the Morgol (Queen) Elrarhiardon and her daughter Lyralathuin are "El" and "Lyra", respectively, to those who know them personally. The legendary wizard Ghisteslwchlohm, who may or may not be from Herun (though his name follows their conventions, according to the Morgol) typically goes by Master Ohm.
Journey to Chaos: The names Nunnal Enaz gives to her inventions are so long that her husband joked it takes longer to say them then describe what they do. An example of what she considers a short name is "Noitearc Powered Orderly Transmission Jammer".
When Michael Moorcock's multiple-continuity recurring villain Gaynor the Damned started to appear in non-heroic-fantasy settings, he often used the name Paul von Minct or van Minct. The Dreamthief's Daughter reveals that his original version, a Nazi Nobleman, was named Gaynor Paul St Odhran Badehoff-Krasny von Minct.