Earn Your Title

This is where a character has a nickname that arose from something they did in the past, usually infamous. This is usually a title gained as a direct result of something they did and is nearly guaranteed to be descriptive of the person it's referring to. This is what usually leads to someone being called The Butcher.

Similar to Appropriated Appellation except the person rarely if ever uses the title. If the title is used in a comedy, expect a Noodle Incident to explain how the character earned it.

Related to The Magnificent but the title tends to describe the person and more often than not gives at least a little backstory. Sufficiently awesome ones are the Red Baron.

Anime and Manga

 * Black Lagoon has Roberta, an unassuming housemaid who turns out to be the "Bloodhound of Florencia." So known because she was once an assassin for FARC known for never failing to kill a target.
 * There's also Sawyer "The Cleaner". She cleans up messes, usually in the form of people who haven't exactly died yet. Not that it stops her for very long.
 * Revy is also known as "Two-Hands". And there's little mystery why..
 * Balalaika's unofficial nickname is "Fry Face" for the numerous burns on her face that she received during the war in Afghanistan. I wouldn't suggest calling her that to her face though. Just saying.
 * Trigun: Vash the Stampede is known as the "Humanoid Typhoon," mainly because any area he's in usually turns into a disaster zone by the time he's through.
 * The Dirty Pair get their show named after their infamy. Just don't call them that to their faces.
 * Sanosuke Sagara of Rurouni Kenshin is nicknamed "Zanza" because he wields an oversized zanbato.
 * Kenshin himself is called "Battousai" (more or less "kills on the draw") because of his technique or "Hitokiri" (manslayer) because of his former job as an assassin.
 * Fullmetal Alchemist: One episode has Barry The Chopper. And it's no surprise why, . They could've easily gone with The Butcher for this one - and, indeed,.
 * Guts from Berserk is known as the "Hundred Man Slayer" due to his single-handed massacre of a hundred Blue Whale Knights at the midpoint of the anime.
 * This is also Manji's nickname in Blade of the Immortal for much the same reason, although in his case he earned the nickname in his backstory.
 * Common enough among the upper ranks of the titular female warriors in Claymore, usually after a signature technique or ability. The exception is 'Theresa of the Faint Smile' for the fact that she never changes expression in battle. The warrior with the greatest skill at sensing youki also gets designated 'The Eye.'

Film

 * As noted on The Butcher, General "Bloodbath" McGrath in Wild Wild West (1999).
 * Boris the Bullet Dodger from Snatch. He dodges bullets.
 * Apparently, while lying on the ground.
 * There's also Bullet-Tooth Tony, who earned his nickname by being shot six times, surviving, and having the bullets melted down into his false tooth.

Literature
"Vimes: "Well, that's an unusual name." Prince Khufurah: (deadpan) "No, the name Ahmed is actually very common where we come from.""
 * Discworld:
 * "71 Hour Ahmed" from Jingo. From the book:


 * Feet of Clay reveals that Sam Vimes has earned the nickname "Old Stoneface", in some quarters which was originally bestowed on a famous ancestor of his. Said famous ancestor had a second, rather more respectful nickname of "Suffer-Not-Injustice Vimes"; apparently it's In the Blood.
 * Lyra Belacqua in His Dark Materials gets dubbed "Lyra Silvertongue" (and occasionally just "Silvertongue") by Iorek, because of her ability to beguile and fool people with her words, and her ability to "talk her way" out of anything.
 * Beka Cooper of the Tortall Universe eventually earns the nickname Terrier for her tendency to never let any case go.
 * Among the Heralds of Valdemar, Firestarting is one of the rarer Psychic Powers, and Lavan Chitward is dubbed "Lavan Firestarter" by the King for being better at it than most. He becomes known to history as Lavan Firestorm after conjuring one in a war.
 * The only way to get any kind of name in the children's book series The Borribles: until you've earned a name by an impressive feat of daring  the best you can expect is to be referred to as "hey, you!" The plot of the first novel is driven in part by the protagonist's desire to get a second name (which is not unprecedented; one of his associates has several names, each commemorating some memorable deed.)
 * The only way to get any kind of name in the children's book series The Borribles: until you've earned a name by an impressive feat of daring  the best you can expect is to be referred to as "hey, you!" The plot of the first novel is driven in part by the protagonist's desire to get a second name (which is not unprecedented; one of his associates has several names, each commemorating some memorable deed.)

Live-Action TV

 * Spike of Buffy the Vampire Slayer is known as "William the Bloody". It's assumed to derive from his violent vampiric ways for three seasons, then revealed to date from his life as a sweetly dorkish human, when his attempts at poetry were mocked as "bloody awful."
 * Another example, Spike.
 * In Stargate SG-1 the team escapes an alien prison with a wise and helpful old woman; then they learn she is known as the "Destroyer of Worlds".

Tabletop Games

 * Kharn the Betrayer from Warhammer 40,000 earned his title after slaughtering his way through two Chaos Space Marine legions, one of them his own. We're not sure if he refers to himself that way, since he usually only says things like "BURN! MAIM! KILL!," "BLOOD FOR THE BLOOD GOD! SKULLS FOR THE SKULL THRONE!" or "RAAAAAAGGHHH!!!"
 * Exalted, naturally, has quite a few of these. Probably the most prominent is the god known as the Unconquered Sun. Guess how he earned the name.
 * Both Werewolf: The Apocalypse and Werewolf: The Forsaken feature the idea of "deed names"—that is, werewolves who've attained deeds of great Renown will often take on a name to reflect it, such as "Evan Heals-the-Past" or "Dares-the-Night."

Toys

 * In Bionicle, warrior-class Skrall are not allowed to have any sort of name unless they are awarded one for their deeds.

Video Games

 * The Elder Scrolls IV get's you "The Hero of " and "The Hero Of Tamriel" from the main quest, Arch Mage (and lesser titles you get as you rise in the guild before that) from the Mages Guild quest, Head of the Fighter's guild,   from the Thieves Guild, Knight Of The Nine for the quests from the Knights of the Nine expansion and   from the Shivering Isles expansion. When you get them, certain NPCs will mention them (most notably the first, which causes the vast majority of NPCs to say "You're the one who closed the gate! The Hero Of Kvatch!?" as their default line and the Mages guild titles, which make everyone in the guild greet you with "Hello [rank]").
 * In Overlord your jester follows you around in your castle and hails you with various titles depending on your actions ("Saviour of Elves", "Abuser of jesters" etc). In the sequel his successor also makes little songs to go along with the titles once you take a Harp from the Elves, from which he'll start a band with.
 * In Fable I you can either earn your title, or you can buy them from the appropriately named "Title Vendor".
 * World of Warcraft lets you earn titles by completing achievements, which you can then chose which one to show, if any. This is just to show off, as NPC's won't care if you conquered Ulduar or became exalted by your factions capital cities.
 * The player character of Ace Combat games often pick up nicknames as the plot progresses. They tend to be along the lines of Demon Lord. And in Ace Combat Zero, your wingman is named Solo Wing because he once returned from a mission with one wing shot off.
 * Metal Gear Solid 3: Snake Eater shows how Naked Snake earns the title of.
 * Sewer Shark, where you start out in the opening cutscene as Rookie, then (in the same cutscene) get assigned the call-sign of Dogmeat, earning Ratbreath, Exterminator, then Beachbum as you successfully progress through the levels.
 * The NIS Roguelike Zettai Hero Project is all about earning the right to be called the Absolute Victory Unlosing Ranger and the faith of the world. Given that the main character starts out as a level one nameless bystander thrust straight into the Final Boss Battle, this turns out to be quite the endeavor.
 * In Dragon Age 2, the PC is referred to as the Champion of Kirkwall, although due to the How We Got Here framing device, the player doesn't find out how they earned that title until about 2/3 of the way through the game.
 * In Tales of the Abyss, Jade earned his title "The Necromancer" because he would scavenge corpses after battles Contrary to rumor, all his troops are alive and not even slightly zombified.

Web Comics
"Mab: Friend of beer-wenches? Dan: Hey, now! I earned that title just like the rest!"
 * Richard from Looking for Group has so many of these it's used for a Running Gag.
 * They're based on kills.
 * In an early Dan and Mab's Furry Adventures story, it is revealed that Dan's full title is "Daniel Ti'fiona: warrior for hire, slayer of the doomknights, bringer of peace, friend of beer-wenches". Lampshading quickly ensues.

Machinima

 * Danial the destructive, from Never Ending Nights. He isn't a bad person, be he screws up in such ways that is causes a lot of destruction.

Real Life

 * Too many, some of whom probably didn't deserve them.... 'Vlad the Impaler' probably deserved his, though.
 * The monarchs of England mostly earned theirs: William the Conqueror conquered England; Richard the Lionhearted was a valiant soldier; Alfred the Great saved his people from being wiped out by invading hordes of Horny Vikings; and Edward the Hammer of the Scots hammered the Scots (and the Welsh; and the Irish; and the Jews...) However, YMMV as to whether Bloody Mary and Good Queen Bess deserve those nicknames.
 * Often the case with nicknames one earns from one's peers in the military.