A Running Gag in Christopher Anvil's "The Trouble with Cargoes" stories: the boss of the shipping company renames ships based on how well or (usually) badly they've performed recently. Which is why his line has ships called Moron's Delight and Spittoon.
In Lola Rose, protagonist Jayni spends most of the book living under the alias of Lola Rose; she and her family are hiding from her abusive father. Even at the end of the story after he leaves for good, she decides to break with the past by continuing to be known as Lola Rose. It's also symbolic of a break from her father since her original name was a portmanteau of her parents' names (Jay and Nikki.)
Cookie has a plot involving a girl and her mother fleeing from an abusive father. The heroine, Beauty, is a plain and overweight girl who has struggled to live up to her name; but when she and her mother start a successful cookie-making business, she becomes known as Cookie (also a play on her surname, Cookson) and decides that she is much happier to live under this name.
By Work:
2666: Benno von Archimboldi is named after Guiseppe Arcimboldo, an artist Hans Reiter read about while going through Anksy's diary. The von is associated with his Germanic heritage, but it's also a way for Reiter to remember Baroness von Zumpe.
In The Amy Virus, protagonist Cindy Butt renames herself Cyan Beaut as part of the process of discovering her identity and rebelling against her parents' abuse. Her mother promises to make it official by allowing her to legally change it to that new one at the end of the story.
Serfs are allowed to change their name when they gain legal adult status (Stile chose his name from a piece of farm equipment that allowed him his first experience with horses) Serfs who win The Great Game and gain Citizen status are allowed to change them again (Rifleman does this, commemorating the trapshooting game that won him his Citizenship).
Werewolves receive a full, four-syllable name. They are given the first syllable at birth. They receive their second when they are officially made pack members (around five or six years of age - members of the same peer group all get the same second syllable). The third is granted by the Pack Leader at around nine or ten years old, after a First Kill (successful solo hunt). The fourth is received after a wolf's ritual first mating - traditionally both partners taking the other's first syllable as their last. It is apparently traditionally the first for both parties. A werewolf isn't considered a full adult Pack member until gaining the fourth syllable. Adept Brown's werewolf companion only had a three-syllable name because She was a lesbian and refused to mate with a male.
In The Balanced Sword, the Intelligent Toads are given one name when they are born and choose a second name with some personal significance when they become adults. One of the protagonists of the trilogy is a Toad named Poplock Duckweed, and his introduction shows the event which inspired him to choose the name "Poplock".
In A Brother's Price, little Neddie was not born with that name. She was adopted in order to save her from being executed with her family, as she was a toddler at the time. Her adoptive family renamed her.
Two examples stand out in the Chalet School series, courtesy of serial Nicknamer Joey Bettany / Maynard. Firstly, Eustacia Benson becomes known as 'Stacie' in Eustacia after getting injured on a mountain and subsequently taking a level in kindness. Secondly, in Theodora, Jo gives troubled teen Theodora Grantley the nickname of 'Ted' to represent her wiping the slate clean by starting a new life at the Chalet School and putting her Dark and Troubled Past behind her.
Street rat "Roach" chooses Briar Moss when he needs a legal name, Living Circle religious dedicates choose naturey names when they join a temple and academic mages invent some kind of typically fancy-sounding last name when they get their credentials.
It doesn't always work out in the mage's favor though, such as with Frostpine, who chose the name because he thought frostpines were pretty trees. When he actually traveled to where pines got covered in frost, he discovered that he hated the associated climate.
Her previous name, if she had one, isn't shown, but Joat in The City Who Fought picked her own name as an anagram of "Jack-of-all-trades" because that's how she sees herself - as someone who can do a bit of everything.
In Jeramey Kraatz's The Cloak Society, Misty wants to be The Mist. When she is certain she is not up to rescuing Gage, he appeals to her that it was beyond Misty's powers, but he thought that The Mist could do it. This inspires her, and she's able to pull it off.
Captain's Fury has the moment when Tavi first publicly identifies himself by his true name instead of the nickname he's been known by since infancy. And outs himself as the grandson of the First Lord Gaius Sextus and heir to the throne of all Alera, putting an abrupt end to the Succession Crisis that had been brewing since Book 1. This wasn't news to the readers, but it was quite an in-universe Wham Line for those who witnessed it.
"I have been known as Tavi of Calderon, [...] but my name is Gaius Octavian."
In the penultimate book, Princeps' Fury, Tavi is named Tavar by his Canim allies. It's a word in the Canim language that happens to sound like his real name, or at least his nickname, which is convenient. Later, he learns that it's the word for a small, very dangerous predator, similar if not identical to a wolverine.
In the final volume, First Lord's Fury, Gaius Isana gives the traitorous Lady Aquitaine a more fitting name:
For my husband's memory, for my child's future, for those whose blood is upon your hands, I defy you. I name you Nihilus Invidia, Invidia of Nusquam, traitor to the Crown, the Realm, and her people.
Tendu of The Color of Distance have three sentient stages in their life cycles, bami, elder, and the optional enkar. As bami they chose a symbol to be their name, and with each stage it becomes more elaborate. A visiting human assigns words to these symbols so she has an easier time with names, and sees the bami Ani become elder Anito, and later the enkar Anitonen.
In Confessions of Felix Krull, when the protagonist becomes employed as a liftboy at the Hotel Saint James and Albany in Paris, the director tells him that from now on he will answer to the name Armand, to show him who's boss and because he considers "Felix" too intimate and pretentious.
In The Count of Monte Cristo, Edmond Dantes takes on several different names. Lord Wilmore is the title he takes when performing acts of generosity and the eponymous Count is his new central persona as he gets his revenge. He only reveals his old name to his enemies just as he has defeated them, as the final blow.
In Alexey Vinokurov's The Country of Three Lands, a goblin (whose race is viewed as Always Chaotic Evil) undergoes a Heel–Face Turn. As goblins are notorious for foul language, this one teaches himself to say "oh, blin" (sort of a milder equivalent of "damn" in Russian) whenever he wants to curse. He promptly gets nicknamed Oblin.
The Dalemark Quartet: At the end of The Crown of Dalemark, the new king takes the name Amil, which is one of the names of the Undying spirit of the land who is mostly called The One. This represents the king taking on the burdens of The One specifically rooting out the renegade mage and descendent of The One, Kankredin.
In Sarah A. Hoyt's Darkship Thieves, Thena tells Kit he doesn't have to change his name when they marry, but he insists.
In the sequel novels (of questionable canonicity) to Harry Harrison's Deathworld books, the battleship recovered in the short story is renamed from its original Imperial name Nedetruebla ("indestructible" in Esperanto) to Argo. In the second story arc of Return to Deathworld, Jason figures out what the name Argo refers to and freaks out, considering their current mission directly parallels the ancient myth (even his first name fits). In a later novel, the ship is destroyed by sabotage, indicating they probably should have kept the original name.
In Dinner at Deviant's Palace, the cult gives a new name to every member when they join, to help separate them from their own life. Inverted at the end, when the character called Sister Windchime renounces the cult and changes her name back to Barbara.
In Dinoverse, the lieutenant raptor of a pack gets named Junior since he's always hanging with the slightly smaller "boss". When he falls down a hole with only one of his sickle claws intact, the same character changes his name and starts calling him Hook.
Agnes Nitt from Terry Pratchett's Discworld series renamed herself Perdita to sound more mysterious. She actually wanted to be "Perdita X Dream" but even she realized her down-to-earth Lancrian peers wouldn't take her seriously that way; they were already referring to her as "Agnes what calls herself Perditax". It got complicated when "Perdita" became more and more of an independent split personality with each book, but at first it was just Agnes calling herself Perdita.
This is significant in Divergent, as characters changed their names to abandon their old faction identity:
The main character Beatrice becomes known as Tris instead of Beatrice. While this is a nickname, it's meaningful because it is significant in the character adopting a Dauntless rather than Abnegation identity.
Four decided to call himself Four because he only has four fears in the fear landscape. His original name was Tobias, but as he was abused by his father that's also one reason he wanted to abandon that identity.
Doctor WhoExpanded Universe: Done by a species in Original Sin, after losing an extremely unpleasant war with the Earth Empire. The two Hith met in the course of the book are named "Homeless Forsaken Betrayed And Alone" and "Powerless Friendless And Scattered Through Space".
The original name of the girl Dodger rescues in Dodger is never given. The Meyhews call her Simplicity, although she says to Dodger "I think I am not very simple". By the end of the book, she's Serendipity.
In Richard Powell's Don Quixote USA, the main regiment of the San Marcan army, known at the start of the book as the Regiment of the Thirteenth of September, changes its name every time the government changes leaders. According to the Generalissimo's second-in-command Carlos, very few dates remain unused.
Dragon Jousters: At the end of Joust, Vetch abandons his serf name and takes back his original name of Kiron.
In Dragonsdawn, Tarvi Andiyar changes his name to Telgar, which was originally his wife's surname. He never admitted how much he loved her until she was dying and made the change to honor her sacrifice to help the Pern colony.
Later in the timeline this is in the backstory of all male dragonriders, who replace part of their name with an apostrophe. So when Lytonal became a dragonrider he became L'tol. After he survived his dragon's death he became Lytol.
The Dresden Files: Harry Dresden has a penchant for nicknaming things, groups, and individuals.
In Death Masks when Harry first encounters the Archive, he doesn't just recognize this five-year-old as a powerful and dangerous force to be reckoned with, but also a child. She has no given name because her mother, the previous Archive, never gave her one before something happened that put her into a coma. This means she has been the Archive all her life, rather than inheriting the mantle in her adulthood with her own developed personality and mind to maintain her own person. So Harry calls her Ivy and treats this powerful being like any other girl, like allowing her to play with his cat. The name is the first step in Ivy slowly developing her own distinct personality separate from the Archive's massive amount of information (namely all knowledge either written, typed or now printed) as well as personal memories of all previous Archives.
The shadow of the Fallen Angel Lasciel resides in Harry's head for several books. Eventually after years of enduring her and not giving in to temptation to take up her Coin, he asks the shadow a question: how long has anyone else ever lasted against a shadow? She realizes with some hesitancy no person has lasted more than a month or two before taking up the coin. He further notes that if his mind is malleable enough to turn to evil, then as the shadow lives in his mind, she is just as malleable. He argues that she is distinct and now different from the True Lasciel and her absorption into Lasciel upon his claiming the Coin is equivalent to her death. So, he nicknames her Lash. This pebble starts a rock slide to the point she eventually turns on Lasciel, renouncing the Fallen and willingly gives up her existence to save Harry's life from a powerful mental attack. All from a nickname Harry gives.
Archangel Uriel pointedly warns Harry against using the nickname "Uri" for him again. The "el" ("of God") part of his name is a very important part of Uriel's identity. Thus, the possible changes using the nickname could invoke would not be positive ones.
Earthsea has many examples, as the power of a name is a prominent theme in the books.
In a world where knowing a thing's true name allows you to control that thing, it's common practice for a person to have one name as a child, then have a rite of passage into adulthood in which that name is discarded and replaced with two others, their secret true name and a public name which everyone will call them from then on. The protagonist of A Wizard of Earthsea starts off with the name Duny; he is given his true name, Ged, by the mage Ogion and calls himself by the name "Sparrowhawk".
In The Tombs of Atuan, the rite turning Tenar into the priestess involves taking away her name; henceforth, she is Arha, the Eaten One. Ged restores "Tenar" to her, a significant plot event.
Ged: You must make a choice. Either you must leave me, lock the door, go up to your altars and give me to your Masters; then go to the Priestess Kossil and make your peace with her — and that is the end of the story — or, you must unlock the door, and go out of it, with me. Leave the Tombs, leave Atuan, and come with me oversea. And that is the beginning of the story. You must be Arha, or you must be Tenar. You cannot be both.
In Always Coming Home, people in the Valley tend to have three names throughout their lives; as children, as adults and as old people. The mother of Stone Telling was Willow as an adult, and once she broke up with Terter, demanded to be called by her childhood name, Towhee. It was considered an extremely wrong action which her daughter never accepted, and upon her death, she was mourned as Ashes. Stone Telling herself also had a fourth (or rather, second) name while living among the Dayao.
In Eccentric Neighborhoods Don Álvaro had originally named his oldest daughter "Milagros" (Spanish for "miracles"). He ends up naming her Clarissa (derived from the Germanic name Clarice, itself derived from the Latin clarus, meaning bright, clear or famous) because she is so intelligent. The rename also sets her apart from her sisters' names which are based upon poetry or mythology.
The Empirium Trilogy: Corien renamed himself after he escaped the Gate. He hates his original name, Kalmaroth, seeing it as an indelible reminder of his former failure during the Angelic Wars.
An Encounter and an Offer has a fae boy being renamed to Arthur, after being taken by Sir Kay as a squire. He, however, has no idea why.
In the After the End series Endworld, nearly every member of the Family goes through this on their 16th birthday, choosing a new name for themselves from the thousands of books they have stockpiled.
In Robertson Davies' Fifth Business Boyd Staunton becomes Boy, an icon of youthful success, while Dunstable Ramsay starts calling himself Dunstan, after Saint Dunstan, and Paul Dempster ditches his old identity to become Magnus Eisengrim.
Forest Kingdom: It's revealed in book 4 (Beyond the Blue Moon) that Prince Rupert renamed himself Hawk after Robert Hawke, a comrade in arms whom he respected.
Fox Demon Cultivation Manual: Rong Bai's original name was Tu Shan Bai. He changed it to Tu Shan Rong Bai in honour of his mother, but removed one radical from her name. The "Rong" in Rong Sang's name is written 榕, while the "Rong" in Rong Bai's name is written 容 without the tree radical (木).
In Gene Stratton-Porter's Freckles, Freckles refuses to give the name given him at the orphanage. McLean offers him his own father's name.
"I will tell you what we will do, my lad," he said. "My father was my ideal man, and I loved him better than any other I have ever known. He went out five years ago, but that he would have been proud to leave you his name I firmly believe. If I give to you the name of my nearest kin and the man I loved best—will that do?"
Later, he learns his original name, at birth, as part of discovering his family. Then Angel's father talks to him:
Under Freckles' earnest eyes the Man of Affairs answered soberly: "I think I have, Mr. O'More."
That was the first time Freckles heard his name from the lips of another. One second he lay overcome; the next, tears filled his eyes, and he reached out his hand. Then the Angel's father understood, and he clasped that hand and held it in a strong, firm grasp.
In Alex Gino's George, George is a transgender girl who starts calling herself "Melissa" (which is reflected by the narrative referring to her as "George" until she sees herself as "Melissa" in the mirror) after she finally gets to dress up as a girl.
In Victoria Forester's The Girl Who Could Fly, at the end, Conrad is told by his father that he has to stop calling himself Harrington and no longer associate with his parents. He agrees.
In the Harry Potter series, Voldemort assumed his name upon becoming the Big Bad and casting away his connection with his Muggle father, whose first name of Tom he shares. Voldemort actually comes from an anagram of his full name "Tom Marvolo Riddle" to become "I am Lord Voldemort". In order to retain this anagram, his name tended to be changed in various languages.
The cast of Haunted (2005) are mostly Only Known by Their Nickname, and the nicknames in question come from the stories they tell, most of which are linked to their secret crimes and shames. "The opposite of superhero names."
Heralds of Valdemar: It's a part of Tayledras culture that individuals may change their descriptive "use-names" after life-changing events. Songwind, one of the heroes of the Mage Winds trilogy, changed his name to Darkwind after a terrible accident led him to abandon magecraft. Persons adopted by the Tayledras also take new names, especially if they want a clean break from their past.
Abbe Prévost's Histoire d'une Grecque moderne: The Greek concubine Zara is set free and decides to reclaim her heritage by changing her name to Théophé, representing her Hellenic origins.
Hive Mind (2016): People who come to the Sea Farm as driftwood often take new names to indicate their new life. When she comes back from the Hive, Celandine takes the name Tressa, meaning 'third', to indicate that this is the third part of her life.
The renaming of Haven from the People's Republic of Haven to the Republic of Haven signifies a seismic shift in that particular entity's politics and government and completes Haven's gradual Heel–Face Turn. As a result, Manticorans force themselves to switch their nickname from "Peeps" to "Havenites" — the Peeps were a People's Republic of Tyranny (albeit with quite a few sympathetic characters trying to make a change), whereas the Havenites — not just individual people, this time, but the nation as a whole — were a Worthy Opponent in a Good Versus Good scenario that only ended when Eloise Pritchart decided to throw a Spanner in the Works of the Mesan Alignment and took off for Manticore to kickstart the Grand Alliance. Phew.
The planet originally exploited by Manpower Incorporated and called Verdant Vista eventually rebelled and renamed itself Torch, becoming a star nation of freed genetic slaves, i.e. a beacon of freedom. Notably, the Mesans continue to call it by its original name.
Treecats who have adopted humans regard the human name they're given as an important part of the bond, though they keep their original names for use among 'cats.
Since treecat names are descriptive it's possible for a treecat's name to change multiple times during their life. A notable example is Singer of Sorrow, her name was changed to that after the rest of her clan was wiped out in the Yawata strike leaving her the Sole Survivor.
Also, the Star Kingdom of Manticore later becomes the Star Empire of Manticore, after the newly-discovered Talbott Cluster petitions Manticore for annexation, increasing the number of systems in the former Star Kingdom by several times. At this point, the Star Empire's total population is about 41 billion sentient beings (including humans, treecats, and Medusans). Queen Elizabeth III Winton is now known as both Queen and Empress.
In The Horse and His Boy at the end Shasta changes his slave-name back to his birth name Cor after he is discovered to be the long-lost Prince of Archenland.
Hunter's Moon (1989): Todds change their names to reflect their mate's family name. For example, A-ran changed his name to A-ho after coupling with O-ho.
Hurog: In Dragon Bones Ward invokes this trope when he renames his father's fierce and dangerous stallion from the evil-sounding "Stygian" to "Pansy", and endeavours to change the horse so that the new name fits. Ward is good with horses, and the stallion's "viciousness" was more due to mistreatment than anything else, so this trope works.
In I've Been Killing Slimes for 300 Years and Maxed Out My Level, Azusa rewrites her name in Katakana upon reincarnating, to dissociate from her old life. This is something that may be lost to non-Japanesenote The connotation being she no longer sees herself as Japanese., so the Animated Adaptation represents it by having her change her name order, putting her family name last rather than first, and the anime's English dub sidesteps the issue.
Invisible Man: "It is time Ras the Exhorter become Ras the DESTROYER!"
In The Machineries of Empire, Kel Cheris discards her faction name and returns to her family surname at the end of the first book to show that she is no longer aligned with her faction.
Many characters choose to abandon their old names with their old lives. Among the Malazan Army, this is actually a requirement, and the soldiers' new names are usually chosen by their drill sergeant based on their personality (Tarr, Bottle, Truth), a quirk (Blend, Limp), as a joke (Kindly, who is not), or an event (Braven Tooth, who broke one off in a bar fight).
Subverted with Fiddler. In House of Chains, he renames himself Strings in order to sign up with the Malazan military again. Nobody who's ever even heard of him buys it, so he eventually goes back to Fiddler.
Smiles was nicknamed thus by her squad's drill sergeant because she never does so and instead tries to kill everyone with her stare.
In Midnight Tides, Silchas Ruin gives Scabandari the name "Bloodeye" while the latter boasts about how no one can oppose them in this new world. Silchas explains how that's due to the blood that now stains Scabandari's vision, implying there's more to it than just the battle they just fought, and Scabandari certainly has left a trail of blood and devastation behind. He is not too pleased with his new name but nonetheless proceeds to knife Silchas in the back, leading many readers to suspect that Silchas knew of the coming betrayal.
The Maze Runner: Everyone who enter the Glades are given new names taken from famous real-life people, mainly those from the scientific field. A few of them have their names revealed in the prequel novels; Tessa's birth name is "Deedee", while Thomas' is "Stephen".
"Lily!" he repeated. "Little snow white lily! Peaches is a good name for you if you're referring to sweetness, but it doesn't fit for colour. Least I never saw none white. Lily fits you better. If you'd been a dog, I was going to name you Partner. But you're mine just as much as if you was a dog, so I'll name you if I want to. Lily! That's what God made you; that's what I'm going to call you."
In Edgar Rice Burroughs's The Monster Men, Professor Maxon and von Horn dub Number 13 "Jack". It doesn't stick. When he gets called "Bulan" by the Malays, however, it does.
Monster of the Month Club: Sparrow Earth thinks of her, her sister's and her daughter's respective renamings as meaningful, to represent the family's lifestyle as "children of the Earth". Rilla's less convinced.
Sparrow Harmony Earth was born Donna Knox, went by Donna Pinowski when she was married, and returned to her maiden name after they split up. Book 3 reveals that "Sparrow" was her husband's nickname for her because she was rather flighty and reminded him of a sparrow in flight.
Poppy Harmony Earth was, after a string of marriages that each ended in turn, Sally Knox Bailey Hailey Hobbs Street.
Rilla Harmony Earth used to be Rilla Pinowski.
The Moon and the Sun: After the Turkish slave Odelette is freed, she changes her name to Haleed and becomes a practicing Muslim.
In Jane Austen's Northanger Abbey, Catherine's younger sister Sally changes her name to... Sarah, for what young lady of common gentility will reach the age of sixteen without altering her name as far as she can? Or dropping one's childhood's family pet name might count as Downplayed Trope.
In the Old Kingdom series, Touchstone used to be Torrigan, but took the name of a fool after (in his eyes) accidentally helping the betrayal of the royal family. Also, the first book's Big Bad took the name Kerrigor after becoming one of the Greater Dead; his original name was Rogir, short for Rogirek. Chlorr of the Mask took her name after betraying her calling as an Abhorsen, her real name was Clariel.
The Otherworld: In Industrial Magic, Hans chose his name because he felt ‘John’ wasn’t an appropriate name for a vampire.
In John Milton's Paradise Lost, the narrator comments that fallen angels have lost their names and will get new ones among humanity.
The Quest of the Unaligned: In the world of Caederan, those who are aligned to one of the four elemental magics must change their name to reflect that alignment (i.e. Lahana becomes Laeshana.)
After Alaric transforms Laeshana from an aesh to a orah, there is some debate as to whether she should change her name to Lorahna. She technically doesn't have to, since orahs are elementally unaligned and unaligned names don't need to reflect anything in particular.
In G. K. Chesterton's The Return of Don Quixote, at the climax, Michael Herne reveals that the Severne family are not the ancient noble house they claim to be, having gotten their hands on the title recently and in a legally dubious manner, and their real name is Smith, even though he is in love with the Honourable Rosamund Severne. He leaves, certain he has lost all. Later, he learns that she no longer goes by Rosamund Severne; if he wants to find her, he should ask for "Miss Smith".
Red Moon Rising (Holt): When Rae and Temple are taken into the Kihuut, they are renamed Mayrikafsa and Kalashava.
In Feist's The Riftwar Cycle, the boy Pug is given the name Milamber once he graduates as a Greater Path magician. Interestingly enough he mostly goes by Pug still. The rename was supposed to be meaningful, the fact that it didn't really stick is also meaningful...
In Stephen Hunt's The Rise of the Iron Moon, when Lord Starborn casts off a newborn ship, Commander Black offers her the name Sprite of the Stars; Coppertracks insists, as a steamman, that she be Starsprite.
Thanks to his Tangled Family Tree, Jace changes his surname no less than three times. He was raised believing he is the son of Michael Wayland, so he goes by "Jace Wayland" at the start of the series. The first book's ending reveals that he is the son of Valentine Morgenstern, so he (reluctantly) becomes "Jace Morgenstern". Then the third book reveals he isn't after all and is actually the son of Stephen Herondale. For some time afterward, he goes by his adopted family's surname, before settling on "Jace Herondale" in the sixth book as a way to preserve the family name.
By tradition, mundanes who undergo Ascension take a new Shadowhunter surname. Sophie Collins takes the name "Ashdown" (though she doesn't keep it for long as she marries Gideon Lightwood and changes to his surname shortly afterwards), while Simon becomes "Simon Lovelace", which also doubles as a Dead Guy Junior as he honors his late friend, George Lovelace, who did not survive the Ascension.
After she escaped from the Circle's uprising and her husband, Valentine, Jocelyn Morgenstern changed her name to "Jocelyn Fray", Fray being the portmanteau of her maiden name, Fairchild, and Tessa Gray's surname, as Tessa helped her settle down in New York. Years later, her daughter, Clary, would change her surname from Fray to Fairchild, as she wants to reconnect with her Shadowhunter identity but not with a father she hates.
It is stated that warlocks have a tradition of changing their surnames upon being recognized as one. The names are often connected to darkness or evil things, symbolizing their demonic ancestry. However, we have yet to learn any of the old names (even Magnus' is unknown since he loathes to talk about his past).
The Jace Herondale of Thule changes his name to Janus upon entering this world. (Janus is the Roman god of doorways.)
In Skulduggery Pleasant, mages can control a person to a certain degree if they know the person's given name and they don't have a taken name yet. Because of this, everybody chooses a taken name, and most of them are pretty cool.
In Michael Flynn's Spiral Arm novel On the Razor's Edge, Donovan renames Five as "Pyati", producing much emotion not only for Five but for all his new attendant magpies. At the end, he tells them he will give them all names, and they beg for their dead comrades to receive them posthumously; when he agrees, they are in tears.
In Stargirl by Jerry Spinelli, Stargirl is constantly renaming herself. She compares it to outgrowing a shirt and finding a new one that fits.
The titular princess in The Story Of A Disfigured Princess was initially named "Kamilah", meaning "perfect child", fitting because she's a princess with restrictions but, after mutilating her face and fleeing to a distant village, she renames herself "Barabel", meaning either "outcast" or "stranger", as she leads her life as something of an outcast and, due to no one recognizing her as a lost princess (one the account of her scarred face) and when she initially moves to a new place, she was a stranger.
In The Final Reflection, all Klingons have a Rite-of-Passage Name Change when they choose the career path they will follow in adult life. This is not the only meaningful rename the Klingon protagonist has; by that point in his life, he'd already been renamed once after being adopted out of the orphanage where he spent his childhood, and he subsequently changes his name again following his adoptive father's disgrace.
In the Shatnerverse novel The Return, when Kirk and Picard prepare to mount an assault on the Borg homeworld in the Defiant-class USS Monitor, accompanied by Spock, McCoy, and the senior staff of the recently-destroyed Enterprise-D, the captain of the Monitor has the name on the ship changed to Enterprise for the mission, musing that it won't show up in the history books but he felt it was appropriate.
Star Wars Expanded Universe: In the short story Orientation, Emperor Palpatine orders the training vessel Defiance to be renamed Obedience after the execution of its commander for defying and attempting to assassinate him.
When the Rebel Alliance then the New Republic captured imperial warships. Accuser -> Emancipator, Adjudicator -> Liberator, Avarice -> Freedom (three examples are captured Imperial Star Destroyers).
When a certain character cements their Face–Heel Turn...
"Caedus. My name is Darth Caedus."
In Star Wars: Thrawn Ascendancy: Chaos Rising, we meet a young but promising Chiss from an obscure family. His name is Kivu'raw'nuru, or Vurawn for short. His superior has him apply for a merit adoption into the powerful Mitth family. After he is accepted, his new names is Mitth'raw'nuru, or Thrawn. After the end of his probation period, the suffix "odo" is added to his name. In the story, we also meet a female cadet with the core name Ziara. Who's this Ziara, you might ask. Well, maybe her full name might provide a clue: Irizi'ar'alani. Eventually, after she makes admiral, her affiliation to the Irizi family is removed, and she becomes simply Ar'alani. Had Thrawn stayed in the Chiss Expansionary Force and actually made admiral, he would likewise have been known as Raw'nuruodo.
In Robin McKinley's Sunshine, it's eventually revealed that Sunshine's birth name is Raven Blaise. When her mother cut ties with the Blaise family, she and everyone else stopped using "Raven" and began calling her Rae. By the time the events of the novel occur, she goes by "Sunshine" more than anything else, even within her own family... which is particularly significant since in this setting, a person's true name is the one they're known by rather than the one they were given at birth, and some very old vampires can't even say words related to sunlight.
In Survivor Dogs, pups are given names based on physical traits or behaviors (such as "Nose" or "Squeak"). When they're older they're renamed by either longlegs or themselves during a Naming Ceremony. For example, Lucky was born "Yap" and Lick renamed herself "Storm".
The Sword of Saint Ferdinand: After using a log as an improvised weapon to fend off an enemy squad, Diego de Vargas is named "Machuca" ("machacar" being Spanish by "smash, crush").
In Things Fall Apart, Nwoye takes a new Christian name after he converts. He chooses "Isaac". This is rather significant given what happened earlier to his adopted brother.
In Poul Anderson's Time Patrol story "Gibraltar Falls", Manse explains at the end that Feliz can't return to her own era under her own name, that's recorded history that she never did; she can, however, change her name and shift to a different one. Thomas offers "Mrs. Thomas Noruma".
In The Lord of the Rings, Minas Morgul and Mirkwood forest both had other names before they were taken over by Sauron's team.
When Minas Ithil (Tower of the Rising Moon) became Minas Morgul (Tower of Black Sorcery), the fortress-town of Minas Anor (Tower of the Setting Sun) on the other side of the Anduin was also renamed to Minas Tirith (Tower of Guard/Watch). Tolkien also mentions that Mirkwood (originally "Greenwood the Great") was given a new, third name (Eryn Lasgalen: "Wood of Greenleaves") after the events of Lord of the Rings.
People tend to acquire all sorts of names in all his works. Even objects get renamed: when the sword Narsil gets reforged, Aragorn renames it Andúril.
Aragorn's rename that was initiated to hide his identity from the Enemy, 'Estel' ('high hope' in Sindarin), is especially meaningful as he was foreseen, given the fact that Sauron was coming back and the Elves were leaving, to either be the last man of his line or the one to restore it to its former glory. The foresight came at the first from his grandmother Ivorwen, who also saw him wearing a green stone that would be the source of his other Meaningful Rename - Elessar Telcontar (Elfstone Strider). The stone itself was foretold to rightfully belong to one who would bear its name, and Aragorn's position as the Hope Bringer is Lampshaded many times in the story.
The Children of Húrin: Túrin's frequent renames; he hopes they'll be meaningful and he'll escape his fate; it doesn't work. Usually, his new name is a reflection on the latest tragedy to happen to him: i.e. Neithan (the Wronged), Agarwaen (the Blood-Stained), Turambar (Master of Doom). The final name gets an ironic echo—Master of Doom, by Doom mastered.
The Big Bad of The Silmarillion, Melkor, is given the name Morgoth ("the black enemy") by Fëanor after he steals the Silmarils and killed Fëanor's father. Similarly, Sauron's name before he went evil was (probably) Mairon. ("Sauron" is Elvish for "the Abhorred".)
Many of Tolkien's bad guys are renamed or otherwise lose their names. Sméagol becomes "Gollum". Gríma becomes "Wormtongue". The Nazgûl are nameless, at least in the core books. Sauron's ambassador has forgotten his own name, and just calls himself "the Mouth of Sauron". Even Saruman ends up as just "Sharkey" (which Tolkien conjectures is from the Orcish Sharkû, "Old Man").
Several hobbits have been mentioned in the backstory who have adopted a new family name, apparently as a result of becoming leaders or patriarchs. For example, Gorhendad Oldbuck, who led the colonization of Buckland, renamed himself to Brandybuck, and his descendants like Merry use that family name. Samwise Gamgee, likewise, becomes Samwise Gardner by the end of the timeline, which seems to be the result of his work to reforest the Shire, his becoming the master of Bag End, and being the mayor of the Shire for many decades and a known friend of the King.
In Song of the Lioness, "Claw" is a meaningful rename for Ralon of Malven, since he looked like someone did that to him between his first appearance and his attempt to become Rogue. (It's from when a maid threw acid in his face when he tried raping her mistress.)
In The Traitor Son Cycle, after his Face–Heel Turn, Nita Qwan return to his old name Kevin Orley, which symbolizes his long-forgotten grudge against the Muriens family (the resurgence of which is what motivates his Turn).
Trueman Bradley was born Truman. He changed the spelling after he decided to become a detective because a detective exposes truth.
Uprooted: People receive a name in the Language of Magic from a magical artifact when they're formally accepted as new Wizards or Witches. Defied by Agnieszka, who refuses a name change because her personal identity is strongly rooted in her home community even after she trains in magic.
Also in the same series Miles at one point reflects that he's not eager for the day that he is greeted as "Count Vorkosigan, sir?" This will signify that his father is dead, and he's the new counts. Happens at the end of "Cryoburn,"
In Dan Abnett's Ravenor short story "Playing Patience", Patience's name was assigned hers by the orphanage in which she lived, as were her sisters', Providence and Prudence. At the climax, she concentrates on her true, original name to keep herself together. Ravenor tells her to keep that name secret and safe, and she chooses to be "Patience Kys".
In Aaron Dembski-Bowden's novel Soul Hunter, Talos's slave is named Septimus — and we hear how Primus, Secundus, etc died. When Eurydice is captured, Septimus immediately dubs her Octavia. After Talos rescues her from Attempted Rape, she accepts the name.
Cat names consist of two parts. The first part stays the same forever, while the second part changes. Kitten names all end in kit (eg Hollykit or Snowkit), apprentice names end in paw (eg Sandpaw or Dustpaw), warrior names can end in anything (eg Tigerclaw or Lionheart), and leader names all end in star (eg Bluestar or Tallstar). The clan leader can also rename elders to fit with any battle scars they might have earned, etc... E.g., a cat who lost an eye becomes One-eye. A leader can also change a young cat’s name, the only known instances being because of deformities (i.e. Deadfoot, Lostface, and Crookedjaw).
The protagonist of the first several books starts off as a pet cat named "Rusty". When he joins Thunderclan he is renamed to "Firepaw", due to his red pelt color. Eventually that too is changed to "Fireheart" and then "Firestar".
War With No Name: All the animals pick new names after the Change. For instance, Sebastian calls himself Mort(e), and Jenna becomes Wawa.
The Laurel Crown of Illian is renamed the Crown of Swords after Rand conquers the country, to reflect his military focus.
The city of Aridhol became Shadar Logoth, or Shadow's Waiting, after it was inhabited by Mashadar, following its original inhabitants' corruption by Mordeth.
The thirteen Forsaken, ancient servants of the Dark One, are Appropriated Appellations from epithets used against them when they betrayed the Light: Moghedien the Spider, Sammael the Destroyer of Hope, Ishamael the Betrayer of Hope, Lanfear the Daughter of the Night, and so on. Lanfear is an exception in that she chose her own name — which says a lot about her character.
Ishamael is a notable Forsaken as he goes through several names that reflect his evolution into Nae'blis. First, he's Elan Morin Tedronai, renowned philosopher. Upon swearing service to the Dark One, he became Ishamael, Betrayer of Hope. After deluding himself into thinking he was the Dark One he became Ba'alzamon, Heart of the Dark. Finally, recognizing that he wasn't the Dark One but completely embracing nihilism, he becomes Moridin, which simply means "Death".
The Seanchan frequently rename as they change their social status. Particularly Egeanin, who is disgraced and becomes Leilwin, and Tuon, who had a different name as a child and becomes Fortuona when she ascends to Empress.
Similarly, in the last book Mat is given the name 'Knotai' and Min 'Darbinda', though they continue using their original names outside of the Seanchan court.
Padan Fain goes through a lot of names as well. At first he's just Fain, even after merging with Mordeth's spirit. Later he goes by Ordeith (Wormwood) and Jeraal Mordeth, but still mostly thinks of himself as Padan Fain in his own POV. In the later books, though, as Mordeth's personality becomes more deeply integrated into him and his dark powers expand, he decides he needs a new name. In the last book, having transcended humanity completely and become a creature of raw dark power loosely attached to his mortal body, he/they/it renames him/their/itself Shaisam.
In While the Clock Chimes, Tatti becomes friends (with hints of Puppy Love) with Brush, a poor cleaning boy at the invisibles' palace. After the invisibles are defeated and run away, she decides to ask her brothers to think up a prettier name for him to mark the start of his new life.
In Wicked, Gregory Maguire has Glinda give up on trying to make people call her by the Gillikinese name Galinda as a kind of symbol of mourning after Doctor Dillamond's death.
In Wide Sargasso Sea by Jean Rhys, a retelling of the story of the Madwoman in the Attic from Jane Eyre, the protagonist is actually called Antoinette; she gains the name "Bertha" seen in Jane Eyre as a result of her husband imposing it on her in an attempt to control who she is. On the converse, on a meta level, Rhys's changing the original Bertha's name to Antoinette has a similar effect of changing the character into something she wasn't in the first place, in this case a rounded character portrayed sympathetically and based on her own experiences instead of a random maliciously insane plot device.
Witch World: In The Jargoon Pard, in the opening, two mothers give children names that their lives may be well-set before them. One does it to claim the boy, since she knows they were switched.
The supervillain Madcap, who upon capture cuts a deal with the authorities to become a superhero called Assault (a move which ticks off Battery for several reasons);
The superhero Armsmaster, who after being targeted for 'recruitment' into the Slaughterhouse Nine — a gang of mass murderer supervillains — chooses to escape house arrest with Dragon, change his name to Defiant, and go hunting the Nine;
The supervillain Skitter, who, reacting to the prophecy of the end of the world, negotiates a deal with the authorities to surrender and become a probationary superhero called Weaver;
The superhero Weaver gets renamed Kephri, after mind-controlling almost every Parahuman to fight Scion.note Kephri is an Egyptian sun god, and fits the Endbringer naming convention
The supervillain Glaistig Uaine becomes The Atoner following the death of Scion and takes up the name Valkyrie.
Inverted in Young Wizards: Nita changes the Lone Power'sTrue Name to allow a possibility of redemption, which it takes a few books later.
In the second story arc of the Guardians of Ga'Hoole series, Nyroc, formerly the prince of The Remnant of the Pure Ones, changes his name to Coryn to separate himself from his former life and become an owl of good following his flight from his family.
Throughout the novel that started it all, only two people refer to the youngest Corleone as "Michael": his father and his wife. To everyone else he's "Mike," except his mom, who calls him the even more diminutive "Mikey." And then he executes (pun intended) his master-stroke in the penultimate chapter. The next time he meets his caporegimes, they address him as "Don Michael,"the new Godfather.
Less portentously, Vito Andolini changes his name to that of his hometown, Corleone, when he immigrates to America. He does this to make it harder for his Sicilian would-be killers to finish their vendetta, but also "...to preserve some tie with his native village. It was one of the few gestures of sentiment he was ever to make." (Averted in the film, which had his name changed by a careless immigration clerk on Ellis Island.)
Mary Yoo from Miracle Creek was known as Meh-hee-yah in Korea. When she moved to America as a preteen, her mother helped her pick out the name Mary, the closest approximation she could think of. Her first months and years in America were so traumatic that she started thinking of the two names as different people - Meh-hee-yah was an outgoing girl who got in trouble for chatting too much and could argue her way out of most punishments, while Mary was quiet, obedient, and alone.
Georg Jewell from Shtum was born Georg Friedman, but changed it at age ten after his whole family died in The Holocaust. He picked his name from two sources: "Jonatan's Jewel," his brother's beloved piece of Bohemia glass, and the Jewelly Sanatorium for Autistic Children, where Jonatan spent his final months.
Georg: I was somebody else, so I should change my name and what else could it be?
Green (2009): Green is involuntarily named "Emerald" by the court where she is enslaved- she eventually chooses the name "Green" for herself.
The Ballad of Black Tom: Tommy starts going by Black Tom after the death of his father Otis, saying, "My birth name has no more power over me. It died with my daddy."
The Cat Who... Series: When Polly's new cat is introduced in book #10 (The Cat Who Talked to Ghosts), he's named Bootsie, and turns out to be a real brat. His behavior, and Polly's towards him, improves once she renames him Brutus in book #19 (The Cat Who Tailed a Thief).
RWBY: Roman Holiday: Neopolitan's original name was Trivia Vanille. However, as a child, she had an imaginary friend called Neo; once she realised that her "imaginary friend" was really the early manifestation of her Semblance, she embraced the alter ego as being a part of herself and took the name for her own. Her appearance is therefore a trifecta of her original self, her imaginary friend's appearance, and influences from her relationship with Roman.
In Too Bright to See, trans boy Bug eventually picks his new name: Tommy, after his late uncle Roderick's middle name, Thomas.
The Mermaid's Mirror: When the mermaid Melusina went on land to live as a human woman, she started going by Lucy.
The Mer: Humans who transform into Mer are strongly encouraged to pick a new name to emphasize the deaths of their human selves. Shona's name means "God is gracious" because she's grateful to Him for her life under the ocean. Will named himself after the only thing he had left after the loss of everything from her former life. Val, previously named Elizabeth, gives herself a name short for Valiant or Valor.
The merman's youngest daughter Yria has always been weak, and her siblings worry that she won't be able to survive a long journey. She takes after her human mother Agnete enough to pass for human, so they leave her on land with Father Knud to be raised as a human girl. The archdeacon renames her Margrete and arranges for her to be baptized.
In Dalmatia, all the merfolk take on new names when they convert to Christianity and gain mortal souls. Vanimen becomes Andrei, and Eyjan becomes Dagmar.
The Wolf Den Trilogy: Upon attaining her freedom, Amara becomes Gaia Plinia Amara, Liberta.
The Yellow Bag: Rei ("King") changes his name to Alfonso shortly after meeting Raquel, as he never liked his old name.
Yellowface: The main character's full name is Juniper Song Hayward, due to her mother having had a hippie phase, but she's gone simply by "June Hayward" both personally and professionally her whole life. This changes when June sells a (stolen) manuscript based on Chinese history and culture, and the publisher worries about the optics of a white author at a very white publisher profiting off Asian culture. This leads them to have her publish under the name "Juniper Song," which sounds vaguely Asian. The official reason June gives for the rebrand is that her first book under her own name bombed, so she wants to make a clean start, and she never says she's Asian, so she feels it's on other people for making assumptions. Those who realize "Juniper Song" is a white woman don't buy this explanation for a second.
Zenobia July: When the titular trans girl was deciding on her new name, she chose "Zenobia" because it started with a Z and ended with an A, and "July" because that was when she got her name legally changed, and because it started with the same letter as her original last name, Jarecky.
