Before a duel begins, one character announces himself to his opponent without any prompting because he wants his target to know who is about to pound him.
Causes can be Genocide Backfire, You Killed My Father, or there could be nothing personal and the hero is just doing this For Great Justice. It can lead to But for Me, It Was Tuesday.
This trope is also very common in Japanese anime, manga and videogames regardless of situation: It was part of the Samurai code of honour to tell your opponent your name before fighting them and not doing so was considered rude.
May directly accompany a Heroic Second Wind.*
Most of the Arrancar seem to have some sort of honor hangup where they need to know their opponent's name. Byakuya flat out refuses to give his because he doesn't see any point in giving his name to someone who's about to die, and Mayuri only asks Szayel's name because he wants to know what to label the jar he'll be in. Yes, all of them are guilty of adding in their rank for no real reason. However, only Ulquiorra and Yammy were late on it; it took for Ulquiorra to kill Ichigo to get his last name out, and Yammy did it when he off-screened Rukia, Renji, and Chad.
This trope is directly invoked by Ikkaku, who believes that you should only introduce yourself to an opponent if you intend to kill them. Which makes this line all the more bad ass
"I'm the 3rd seated officer of Zaraki's division, Madarame Ikakku! You don't have to tell me your name, you just have to remember mine...because it's the name of the man who'll kick your ass!"
"From the Royal Enforcement Division, no. 67, my name is Ren. I am your nemesis.''
In Digimon Xros Wars, Shoutmon tends to begin a fight with something along the lines of "We are the ones who will change this world! We are Xros Heart!"
"I, Misao Makimachi, see no compelling reason to give villians like you my name!"
Dragon Ball Z (technically Dragon Ball Kai): "I'm a proud Saiyan who calls Earth home, and I'm here to defeat you. I am the warrior you've heard of in legends, pure of heart and awakened by fury. That's what I am. I AM THE SUPER SAIYAN, SON GOKU!"
Fate Zero: Rider particularly does this, in the form of exposing himself as Iskandar, the King of Conquerors.
''My name is Haruhi Suzumiya and I'm from east Junior high. I have no intrest in ordinary humans! if any of you are aliens, time travelers, sliders or espers, come join me. that is all.
She introduces herself to the Computer President afterdropping kick him. Also, she was accepting his challenge instead of delivering one.
Katekyo Hitman Reborn!: Hibarin from Monster Tamer Tsuna, "I am Hibarin, the dreadful vampire. My address is Demon Valley 2-4. I love Salisbury steak and coconut juice. My hobby is to have fun by myself. And to bite weak people to death. And to play with birds." Cue Tsuna lampshading this trope, "He's giving an introduction when nobody asked for one! And it's taking forever." And Hibari finishing his monologue with this: "And to patrol my castle. That's right. I have one last thing to say. I'm not much of a talker.
Light Yagami from Death Note informs Naomi Misora that he is Kira, approximately one second before her death kicks in.
Magical Girl Lyrical Nanoha A's: "Time-Space Administration Bureau Part-time mage, Fate Testarossa." She does this right after saving Nanoha and right before attempting to place Vita under arrest.
The heroes have a catchphrase that precisely announces a 'I AM/WE ARE XXX' shout by whoever it is to kick ass: WHO THE HELL DO YOU THINK I AM/WE ARE?!"
This trope became Nia's first Crowning Moment of Awesome! "The Spiral King Lordgenome's eldest daughter, Nia Teppelin commands you to stand down, Andiane the Elegant! Are you aware of who I am?" Simon and Yoko instantly did a "holy shit!" expression upon hearing it.
Simon: My Name is Simon. Leader of Team Dai-Gurren. If you've decided to be a wall that's standing in my way, I've got something that will open a hole in you every time. And that something is MY DRILL!
Comicbooks
When a brainwashed and tortured Wolverine first recovers his memories and powers in the "Insane in the Brain" storyline:
Dr. Rot: This is your last chance, Patient X. Do you hear me? Patient X? Wolverine: No... (snikt) Wolverine: My name... is Logan!
This gem from Superman: Man of Steel #96 in 2000, as Eradicator was trying to get him to turn away from his Human upbringing.
Superman: My name is Clark Kent. Get out of my home. Get off my planet.
"That's it! Don't you dunderheads know who I am? I'm Toph Bei Fong, the greatest earthbender of all time! When my friend tells you to calm down, you calm down!"
This classic from 'The Mighty Thor' Vol 1, #379 in 1987, by Thor himself to Jormungand.
But I have many names, serpent, even as you. Vingthor the Hurler, Longbeard's Son, have I been called. Hrodr's foeman, too. In Tyr's ancestral home, wisest Hymir knew my name as Veur; unhappy Hrungnir's playmate some have called me. East of Elvigar in Gianthome they whisper Hloriddi's name. My father called me son. My mother called me darling. And beneath the vaults of Heaven, I am Thor Odinson, the Thunderer, Jormungand's Fear!
Fan Works
In .hack Trilogy Abridged, Haseo's version of this is: "My Name Is Haseo the Terror of Death, you killed my Shino, Prepare to Die!!", and he says it when he battles Tri-Edge.
Konata Productions' Neon Genesis EvangelionAbridged Series introduces Touji Suzahara with him saying "My name is Touji Suzahara. You killed my screen time. Prepare to die!!"
A cult classic, Pokémon Revisited, has Ash burst into every gym with the line "My name is Ash, and I'm here to KILL YOU!" in way of challenging the gym leader.
In "Total Drama Battlegrounds," Ezekiel uses this trope in the virtual reality game after zombies kill his girlfriend, Heather.
The Immortal Game: Twilight Sparkle has a brief, but epic, moment like this when Titan is torturing her, while referring to her as "pony", "unicorn", and by the name of one of her ancestors who fought him the first time around. The pain causes her mind — which had previously fractured from trauma earlier in the story — to fuse back together, restoring Twilight to her true personality and power. Cue asskicking.
Night Raven: Who do you think you are, you wimp? Fluttershy: My name is Fluttershy! I’m a member of the Mirage squadron! And I've sworn to protect Equestria and my friends! I’m a pony that represents the Element of Kindness! But, to you... I will show no mercy!
In The Godfather Part II, Young Vito Corleone/Andolini confronts an elderly Don Ciccio, who asks "Tell me, who was your father?" Vito replies "My father was Antonio Andolini, and this is for you!" He then proceeds to stab him and start a gunfight.
"This is Constantine. John Constantine... asshole."
Apocalypto: "I am Jaguar Paw, Son of Flint Sky. My father hunted this forest before me. My name is Jaguar Paw, I am a hunter. This is my forest, and my sons will hunt it with their sons after I am gone. Come on! COME ON!!"
The first Transformers movie. To clear up all that "N.B.E.-01"/"Ice Man" nonsense the worthless human insects have been calling him, the leader of the Decepticons announces himself: "I AM MEGATRON!"
Beautifully subverted in Once Upon a Time in the West. Harmonica never tells Frank his name. When Frank demands to know, he gives him plenty of names, but none of them his.
Frank: Who are you? Harmonica: Jim Cooper, Chuck Youngblood. Frank: More dead men. Harmonica: They were all alive until they met you, Frank.
Shoshana: My name is Shoshana Dreyfus, and this is the face...of Jewish vengeance!
Literature
In The Princess Bride all the way through the book Inigo has been practicing his speech. After a huge buildup, when he finally gets to deliver it in the climax to his lifelong search, honing his sword skills for the battle of his life, his enemy runs away like a little girl. Of course, Inigo then chased Rugen down, and then repeated the speech several times with increasing volume as they dueled..
Used to great effect in the Codex Alera book Captain's Fury, when Tavi reveals that he is Princeps Gaius Octavian. Happens to be punctuated by a purely coincidental, plot relevant, volcanic eruption hundreds of miles away.
In 1634: The Galileo Affair, by Eric Flint and Andrew Dennis, there's a line something like "My name is Ruy Sanchez de Casador y Ortiz. Prepare to die," then subverts the reference's Heroic Second Wind. Our friendly neighborhood old fart proceeds to slaughter and get cut up, while his much-younger girlfriend-from-the-future wonders when he had a chance to read The Princess Bride and another uptimer realizes he didn't — he's Inigo Montoya's prototype.
Averted in Cordwainer Smith's "On the Sand Planet", where Casher O'Neill, after gaining enlightenment on his quest, does NOT use any of the scenes he has mentally rehearsed for years.
Inverted in A Dance With Dragons, after Theon Greyjoy pulls a Crowning Moment of Awesome by saving Jeyne Pool from Ramsay Bolton and getting both of them to reach Stannis's army safe and sound
Strider: I am Aragorn son of Arathorn, and I am called Elessar, the Elfstone, Dunadan, the heir of Isildur Elendil's son of Gondor. Here is the Sword that was Broken and is forged again! Will you aid me or thwart me? Choose swiftly!
Scrubs does this in Season 7's "Finale", where Dr. Cox is telling a Bedtime story to his son. Cox, as a brave knight, says to a monster (in reality an illness affecting a patient):
Cox: My name is Percival Cox. You're killing my friend. Prepare to die.
"Who am I? I am Susan Ivanova. Commander. Daughter of Andrei and Sophie Ivanov. I am the right hand of vengeance, and the boot that is going to kick your sorry ass all the way back to Earth, sweetheart! I am Death Incarnate, and the last living thing that you are ever going to see. God sent me."
The Doctor: Is this world protected? 'Cause you're not the first one to have come here — oh, there have been so many. And what you’ve got to ask is: what happened to them?... Hello. I’m the Doctor.Basically... Run.
In Andromeda's "Music of a Distant Drum", a season one episode. Tyr loses his memory after a crash, and slowly regains it bit by bit. When he finally remembers:
NCIS Season 7, episode 1 does this with a slight twist. Towards the end, after McGee tries and fails to kill Saleem, Tony says to Saleem, "I told you about every member of the team, except myself. The part I play... I'm the wild card. I'm the guy who looks at the reality in front of him and refuses to accept it." (Technically Tony tells Saleem his name much earlier, but this is the point where he really tells Saleem WHO he is, and right before Saleem is killed.)
Done as strait as an arrow in season 8, episode 23 with Mike Franks' last stand.
Franks: My name is Mike Franks! I figure I got one more fight in me... You want it?
Nikita: Alex does this to Vlad, the man who sold her into white-slavery.
Alex: I am Alexandra Udinov, daughter of Nicholai Udinov. And this is your reward.
Mook Guard: You work, and you live. That is all. You do not complain or laugh or do anything besides work. Whatever you thought, whatever you were does not matter. You are no one now. You mean nothing. (to boy) Who are you?
Katie: I'm Katie fucking Fitch, who the fuck are you?
Lost: Season 5, episode 12, Ben Linus upon approaching Penny Widmore: "Hello. My name is Benjamin Linus". He wasn't prepared to duel her, though; He was about to kill her when Desmond, whom he just tried to neutralized by shooting him, attacked him from behind.
Music
Johnny Cash as the title character singing "A Boy Named Sue" when he meets his father, who gave him that name that caused guys to beat him to a pulp: "My name is Sue. How do you do? Now you're gonna die!"
Also, Johnny Cash at the start of every show he ever did:
"Hello. I'm Johnny Cash."
In The Distillers' "The Young Crazed Peeling", one of the lines in the first verse of the song goes like this:
My name is Brody, I'm from Melbourne
Fitzroy Melbourne, Fitzroy Melbourne
I grew up on Bell St. then on Bennett St.
My mom kicked out my dad for battery
Myths & Religion
In The Odyssey, Odysseus just kicked the butt out of a Cyclops, Polyphemos. As he leaves he brilliantly declares "Kyklops,/if ever mortal man inquire/how you were put to shame and blinded, tell him/Odysseus, raider of cities, took your eye:/Laertes' son, whose home's on Ithaka!" He may as well have given him the precise longitude and lattitude of his house, and just thrown in his social security number, too.
Protip: if you live in Greece's "Age of Heroes" and you're already well acquainted with several mean-tempered gods, wounding the son of Poseidon is almost as dumb as killing Inigo Montoya's dad.
Video Games
Chrono Trigger has Frogs' heroic speech. "My name is Glenn! Long have I carried Cyrus's hopes and dreams, and now I bear the Masamune as well! Henceforth, I claim them as my own! I shall slay the Fiendlord Magus and restore our honor!"
Hakumen: I am the white void. I am the cold steel. I am the just sword. With blade in hand shall I reap the sins of this world, and cleanse it in the fires of destruction. I am Hakumen! The end has come!
Reznov: My name is Viktor Reznov. AND I WILL HAVE. MY. REVENGE!!''
Assassin in Fate/stay night introduces himself formally on initiating a duel, though he doesn't insist Saber identify herself.
In Super Robot Wars, anyone who's about to be on the receiving end of Sanger's BFS will at least get to know that "I am Sanger Zonvolt, the sword that cleaves evil!" Wodan Ymir does pretty much the same thing.
Sir Ano does this in one of the Oaklore quests in Dragon Fable.
Sir Ano: My name is Sir Ano de Berg'rac. You're planning to kidnap my princess. Prepare to die.
Let's not forget Ezio in Assassins Creed II after he stabs Uberto Alberti to death: "The Auditore are not dead! I'm still here! ME! Ezio! Ezio Auditore!"
From Fire Emblem, we get KIERAN, LEADER OF THE FIFTH PLATOON OF THE CRIMEAN ROYAL KNIGHTS! / SECOND COMMANDER OF THE CRIMEAN ROYAL KNIGHTS!.
Dwarf Fortess does this in Adventure Mode with anyone you can talk to, especially the ones you've been sent to kill. Speeches typically have their name, relation to other histrorical figures, kill list, and then the obligatory "prepare to die" if they're trying to kill you.
The GEKICOM Elementals and the STRUQ Team in Ilivais X do this like it's required by law. They're all Large Hams anyway. En Arteya did as well, and technically Ashe too. Justified in that otherwise we'd have no idea who they are, due to their Monster of the Week nature.
Aeofel does this constantly in Penny Arcade's D&D Podcast when he swears Oath of Eminity. Which he does a lot.
Also Katara in "The Southern Raiders", and her insistence that the soldier remember her and her mother.
Ben 10 Alien Force: Said by Kevin. "My name is Kevin Ethan Levin. You killed my father. Prepare to die." Too bad it didn't work.As usual. Though Kevin does eventually manage to kill the guy at the end of the episode.