History Main / MarathonBoss

** The Golem in ''The Millennium Girl'' is surprisingly tough due to its associated quest becoming available while you're about 10 levels too low to match it. When its HP is depleted, it gets back up at half health, putting the player in for a longer fight than they bargained for.
** While a lot of bosses suffer from HP bloat in ''The Fafnir Knight'', the three elemental Dragons get particularly nasty about it. The main issue is that they also summon a core that casts an elemental attack that grows stronger for every turn the core is alive, so you can't just ignore it or it will become too strong to handle. The cores have a non-trivial amount of HP, so you're going to need to take time off the main body to fight it, and the dragon can regenerate it periodically during the fight. All this, while the dragon continues to harass you with deadly attacks. The Great Dragon is the worst of them all, sporting '''72,000''' HP and a core with '''13,000''', on top of sky-high Strength that can one-shot your more fragile party members. You have a GuestStarPartyMember to help you out, but she's so poorly optimized she might as well be a meat shield.
** Other bosses in other entries can qualify if the player simply walks up and challenges them, as they will be sporting a full HP bar which is often too large for the party's resources to handle. This will mandate walking around the floor or boss room to trigger certain map events that will weaken it to manageable levels, going from this trope to PuzzleBoss. Examples include Boiling Lizard and Warped Savior (both from ''Legends of the Titan'').

* The final boss of ''VideoGame/TheDenpaMen''. It's [[SequentialBoss basically three boss fights]] against the Rook, Queen and King without being allowed to heal or change equipment. While the Rook can be basically beat by barraging it with physical attacks, the Queen can use a guard shield to defend itself, and uses some more damaging attacks. They're both easy compared to the King. He has tons of HP and regains some HP at the end of every turn, he attacks twice in one turn, [[TotalPartyKill he can easily sweep your entire party]], he can use guard shields to completely neutralize damage, he flip-flops from being completely invulnerable to magic and being invulnerable to physical attacks (while still being fairly strong against magic), and, near the end of the fight, he flat-out ''becomes invincible'' for a few turns, and there's nothing to do but wait it out. Yikes. The whole sequence of fights can go on for nearly an hour if you're unlucky. They even make their return in the sequels as [[BonusBoss post-game bosses]] and are just as hard. The third game even has you fight all three of them at once.

** The Denpa Men: Rise of Digitoll's [[TheRival Master Squelch]]/[[BonusBoss Self Made King]] is one of these by virtue of [[DamageSpongeBoss his high HP count]], hard hitting attacks and having Master Squelch [[OneWingedAngel transform into]] Self Made King (aka King of Evil) [[TurnsRed halfway through the fight.]] Even if you can strike him down with Light, he'll take a bit to go down.

* ''VideoGame/DisgaeaD2ABrighterDarkness'' took this trope to its logical extreme with its version of [[BonusBoss Tyrant Overlord Baal]]. The fight can easily takes over 30 minutes. To run it down:

* ''VideoGame/DukeNukemManhattanProject'' has pretty normal boss fights, with one exception: The BonusBoss, Wozma. It's an immobile green sphere with about ten times as much health as any other boss in the game and takes a good 15-30 minutes of jumping up and firing rockets at it to kill it. It's pretty well-hidden, requiring you to find all the nukes on Hard difficulty and then take a special path that's only unlocked after you've got them all. Unfortunately, your only reward for beating it is [[CosmeticAward an icon on your saved game]].

** The ultimate BonusBoss of each game certainly qualifies, sporting sky-high HP that dwarfs nearly everything else before them and deadly attacks that can level the party if not defended against. That of ''The Fafnir Knight'' has '''140,000 HP''', paired with a self-healing ability on top of flunkies that have 10,000 each. The ultimate DLC boss of the same game has a record-breaking '''280,000'''.

** Then the Game Boy Advance version added a BonusBoss example for hardcore players. The Kaiser Dragon has 327,500 HP, and can easily take 20 minutes to kill. And once you've beaten him, you unlock the Soul Shrine, which involves fighting every boss from the bonus dungeon in a row, ending with Kaiser Dragon again (though by the point you're taking on the Soul Shrine, you're usually powerful enough to kill everybody quickly).

%%** The [[BonusBoss Omega Weapon]].
* In ''VideoGame/FinalFantasyIX'', the optional Marathon Boss was Ozma because the Ozma challenge was a GuideDangIt, ThatOneBoss BonusBoss LuckBasedMission, in which you would spend more time healing, reviving and waiting to counter its attacks than actually dealing much damage. With a mere 65000 HP, Ozma can be taken down with less than nine hits, but that's before he casts [[StatusEffects Curse]], followed by [[TotalPartyKill Meteor]].

** Many of the Dark Aeons and the mother of all [[BonusBoss bonus bosses]], Penance, from ''VideoGame/FinalFantasyX International''. The weakest of the Dark Aeons has around 1 million HP. Dark Anima has 8 million HP (the highest of the Dark Aeons). Penance tops that with ''12 million HP''. And unlike some marathon bosses, all of them are '''hard'''. This [=YouTube=] video of the Penance fight: [[https://www.youtube.com/watch?v=nIZA3P4hEWI just under 36 minutes]].

** BonusBoss Trema, who has 999999 HP, which is insane considering his defense. Funnily, he still goes down easier than [[ThatOneBoss Paragon]] that ''he killed in the pre-fight cutscene''.

** Yiazmat, the ultimate BonusBoss, regularly takes players as much as 12 hours to kill, thanks to its astronomical 50 million HP. The real kicker? Near the end of the fight, Yiazmat pulls off a little trick that, if not caught and stopped, '''''heals him back to full health'''''.

** [[BonusBoss Vercingetorix]], who has 15.8 million HP (although it's worth noting that the default damage cap in that game is 99,999, not 9,999, and the fight will probably take no more than 15-20 minutes).

** The [[BonusBoss Egg Dragon]] of both ''VideoGame/LufiaIIRiseOfTheSinistrals'' and ''VideoGame/LufiaTheLegendReturns'' is intended to be this, hitting the {{Cap}} of 65,535 HP. However, there's a [[GoodBadBug glitch]] that lets the player humorously subvert this: chuck a Potion at it at the very beginning of the fight, watch its health overflow to a really small number, then hit it with an attack and watch it die. If you want to go at it the "real" way, though, you're in for a long haul.
** And there's no easy way around ''VideoGame/LufiaTheLegendReturns'''s [[BonusBoss Iris]]. Not only do you have to make it through the [[MarathonLevel 200-floor]] [[BonusDungeon Ancient Cave]] just to get to her, you have to take down her 50,000 HP while she throws the game's strongest attacks at you, inflicts status ailments including the dreaded Confuse, and reflects attacks back at their users. [[PercentDamageAttack Percent Damage Attacks]] would help you here, as they do in the game's other tough boss fights...unless you didn't find any in the randomly-generated Ancient Cave. And all this [[CheckpointStarvation with no save points]] on [[UsefulNotes/GameBoyColor a battery-powered portable system]]!

** Second is one of the [[BonusBoss SP Bosses]], Miru Syndrome. The gimmick to her fight is that you are unable to deal much damage to her at first, and must focus on [[HoldTheLine just surviving]] until an event triggers where you get back your partner and the boss' defenses go down to a reasonable level. But how long does it take for the event to trigger? Around eleven and a half minutes, during which the boss goes through six different phases. And while she can be defeated pretty quickly after the event on lower difficulties, the battle can go on for much longer if you're fighting one of the harder versions of her.

** [[Music/LynyrdSkynyrd "Freebird"]], the FinalBoss of [=GH2=], and [[Music/DragonForce "Through The Fire and Flames"]], the BonusBoss of [=GH3=].

* The BonusBoss in ''VideoGame/ShadowHearts'' that is required for the GoodEnding is a real grind. It's not particularly challenging, as its attacks don't vary much, but the fact that you have to fight it with only one character, who takes all the damage and has to do all his own healing, can make the fight last half an hour or more.

* ''VideoGame/ShinMegamiTenseiIV'' has the {{DLC}} {{Bonus Boss}}es Ancient of Days and Sanat Kumaya. The former especially, as it has Diarahan (a spell that restores ''all of its health'') and it will spam it if you hit its weakness (this forces you to get ''another'' DLC that provides the only source of the Brand ability other than Ancient of Days himself). The third DLC BonusBoss, Masakado's Shadow, would be this if not for the fact that it has a turn limit, especially since it doesn't hit terribly hard compared to the other two.

** [[VideoGame/ValkyrieProfile Freya]] becomes an [[BonusBoss optional boss]] you can fight after completing the main game. She has 20 million HP (and that's just on easy mode!) and her attacks, namely [[OneHitKill Ether]] [[ThatOneAttack Strike]], can kill even the highest leveled characters in one or two hits. To even have a tiny hope of winning, your team must be maxed out to [[LevelGrinding level 255]] and be equipped with the strongest weapons and accessories that can be found in the game. You must also have a whole inventory's worth of bombs, so that you can hopefully interrupt her attacks by blowing her up.

** [[BonusBoss Bonetail]] from ''VideoGame/PaperMarioTheThousandYearDoor''. It has a grand total of 200 HP, which is 50 more than the final boss (both actually being big numbers in this game). It will prolong the fights by causing Confusion and healing itself for 20-30 HP per heal, amongst other things. Woe be you if it defeats you after you trekked down all 100 floors to get to it.
** [[BonusBoss Culex]] from ''VideoGame/SuperMarioRPG'', with his four Crystals and a total of over 12,000 HP between the five (with Culex himself having the most). Though you can speed things up a little by focusing your attacks on Culex, that means you'll have to endure the bombardment from him and the Crystals. It's a long fight no matter how you approach it.

** The BonusBoss of ''VideoGame/TalesOfSymphonia'' who unlocks your {{Infinity Plus One Sword}}s, Abyssion, is also a Marathon Boss, featuring higher HP than the FinalBoss and a more dangerous base of attacks. The recommended strategy for dealing with him is to use an "All-Divide," an item which halves all assigned damage and thus makes it even ''more'' of a marathon. The reason this is considered an improvement is that it does not change the effectiveness of your healing, essentially making ''those'' spells double-strength. Later ports of the game have the boss nullify All-Divides, making them pointless.
** Another Tales' BonusBoss, [[ThatOneBoss Nebilim]] from ''VideoGame/TalesOfTheAbyss'', is basically the same, except that there's no All-Divide. Fortunately her damage output has been adjusted downward.

** A rare ''VideoGame/TalesSeries'' example in which the Marathon Boss is ''not'' a BonusBoss: In ''VideoGame/TalesOfDestiny 2'', [[spoiler:Fortuna]], the FinalBoss takes ''forever'' to beat. Look up videos of it on Website/YouTube, and you'll notice that they're often split into multiple parts or have most of the fight edited out. The only indication that they're going down is that the music changes.
** Magnadeus, the BonusBoss from the same game, can also take quite some time to defeat, though not usually as much time as [[spoiler: Fortuna.]]

** ''Perfect Cherry Blossom'' has [[BonusBoss Yukari Yakumo]], who takes ''over 10 minutes'' to defeat, and over 15 minutes if you try to time out her attacks (say, to graze for score). Many shmups take about 20-30 minutes to complete, total. And to even ''get'' to Yukari, you have to beat the [[BonusBoss Extra boss]] Ran Yakumo. ''Twice.'' You see, Yukari's not PCB's Extra boss. She's the Phantasm boss. No other Touhou game ''has'' a Phantasm stage.

** Typically, the last spellcard in any game is absurdly long. The average spellcard lasts about 15-20 seconds, 45 if you're going for the timeout. Final spellcards can last ''two and a half minutes.'' [[https://www.youtube.com/watch?v=h1MR9jOpH94 Kanako Yasaka's final card is particularly terrifying.]] Once again, Yukari takes the cake. Her [[BonusBoss optional]] [[https://www.youtube.com/watch?v=VKz5BJXWDYQ Last Word spellcard]] in ''Imperishable Night'' is an extended version of the aforementioned last spellcard in ''PCB''. Except you're not even allowed to bomb ''at all.''

** There is far tamer example outside of online: a [[BonusBoss Milesaur Tyrant]] named ''Gradivus, the Headless Emperor''. It has ''one hundred million'' HP, the highest of any non-Global Nemesis enemy in the game despite being just level 74, but unlike the Global Nemeses mentioned above, you ''have'' to kill this one in a single sitting. There's ways to reduce that HP relatively fast with [[GameBreaker absurd builds]], but it's a testament to its resilience that even the strongest builds in the game can't one shot it and take a while to bring it down.

** Marluxia, the final boss of ''VideoGame/KingdomHeartsChainOfMemories''. In the GBA version, where most bosses have two, maybe three health bars, he has ''four''. Not only that, but you can't actually damage him normally unless you go through his entire attack pattern. And when you do reach that point, you only have a few seconds since wind is blowing you off. Thankfully he's also open to attack every now and then, but it's unlikely you'll have strong enough cards to really exploit it until after you beat him. [[VideoGameRemake The PS2 version]] reduces his HP and gives you more openings for attack, but also adds a [[SequentialBoss second form]] with more HP than the first, a sleight that does nothing but blow you away from the boss, and another that smacks all the cards out of your deck and forces you to run around and collect them.
** Ansem, the final boss for the [[AnotherSideAnotherStory Reverse/Rebirth]] mode, is just as bad, if not worse, in the GBA version.
** ''VideoGame/KingdomHeartsBirthBySleep [[UpdatedRerelease Final Mix]]'' has No Heart. Like most {{Bonus Boss}}es in the series, he attacks almost constantly. On top of this he has 9 Health bars and excellent defense (Roughly 1800 HP and the most a player can ever do is 10-15 with maxed level and equipment). This amounts to 20-40 minutes of battling, monstrous compared to the 2-5 minutes typical of the series. No Heart takes so long because he is expected to be faced by multiple players at once, in a multiplayer battle, which would result in a more "reasonable" time to beat. When ''Birth By Sleep Final Mix'' was remade for the [=PS3=] (as ''2.5 HD Remix''), No Heart's HP and defense were heavily [[{{Nerf}} nerfed]] because multiplayer is no longer an option in the Playstation 3 version, resulting in a [[https://www.youtube.com/watch?v=nR0llMU8S4M&list=UU7BSMVFWQZmSqZsWUQ63o3g considerably shorter fight.]]
** The vanilla version of the game, and the UpdatedRerelease have Vanitas Remnant, a Monochrome PaletteSwap of a recurring boss throughout the game. He doesn't have much health, 200 compared to the 700 he has when you encounter the normal version at the end of the game, but has staggeringly high strength; 80 compared to his endgame normal version's 26, and extremely high defense; the Remnant has 27 defense compared to the normal endgame version's 15 defense. In addition to that, Vanitas Remnant has several devastating attacks that the normal version didn't have, including one that makes him totally invincible while he launches a series of devastating ranged attacks. But wait, there's more! He also takes 50 percent reduced damage from physical attacks, as well as 75 percent reduced damage from fire, ice and lightning attacks, and is immune to everything else, combine that will his already high defense, and you'll probably spend the entire fight hitting him for ScratchDamage unless you've done an obscene amount of level grinding. ''Then'', if you take damage at any point in the fight, it will almost OneHitKill you unless you have Second Chance and Once More equipped, due to his aforementioned staggeringly high attack, but you can't use the Cure/Cura/Curaga spell to heal yourself, or he will just use Cure/Cura/Curaga on himself instantly, healing him probably back to full health since he has so little health to begin with. So you're forced to use your limited amount of curative items, which will deplete over the course of the fight. The entire fight will probably consist of you dodging his attacks, getting in one or two scratch damage attacks, and then going right back on the defensive until he opens himself up again.
** The series' other {{Bonus Boss}}es are just as bad. From ''VideoGame/KingdomHeartsI'', we have the Ice Titan and [[VideoGame/FinalFantasyVII Sephiroth]]. The Ice Titan is a pain because the primary way to damage it is to deflect one of its attacks back at it, which as the fight goes on, it will do less and less, and often whilst you are in no position to be able to deflect. Sephiroth is easier to damage, but has a ridiculously large shield to whittle down before his health bar even begins to deplete, and has attacks which will almost kill you, even at full health. ''VideoGame/KingdomHeartsII'' has Sephiroth again, who has 15 health bars (the final boss has at most 7/8) and loves to do back-to-back [[HPTo1 Heartless Angels]] and [[TeleportSpam Teleport Flashes]] before you can heal.
** All games seem to end with ridiculously long bosses. ''VideoGame/KingdomHeartsII'' has a final boss with at least 6 different parts to it; one part, [[spoiler:[[GiantSpaceFleaFromNowhere The Giant Nobody Dragon]]]], is even split into 3/4 stages! ''VideoGame/KingdomHeartsI'' has a similar number of parts to its final fight.

*** The optional ones include the [[BladeBelowTheShoulder Zip Slasher]], which is a straight-up DamageSpongeBoss, the [[OurDemonsAreDifferent Invisible]], which is just as hard to hit as it is in [[VideoGame/KingdomHeartsI its original incarnation]] but has a buttload more health, and finally the [[OurDragonsAreDifferent Dustflier]], which is a DamageSpongeBoss that also has absurdly powerful attacks with (mostly) ridiculously wide ranges.
** During her [[ThatOneBoss/KingdomHearts first stage]] [[WesternAnimation/TheLittleMermaid1989 Ursula]] who can be this if you don't know the trick, which King Triton tells you. [[spoiler: You have to use spells on her cauldron until it blows up in her face.]] If you don't do this, you'll have to hit her ''a lot'' because she's the ''only'' boss who doesn't take normal damage. Though, [[LevelGrinding if you level up enough]], Ursula can be easily defeated entirely without magic.

* ''Anime/DragonBallZ: Gokuu Gekitouden'' has Freeza as this, of the [[SequentialBoss series of somewhat smaller fights]] variety. His first form has 200,000 life, and each form after that has even more. The basic outline of the fight is: You fight Freeza's first form (200,000 life) using Gohan, Krillin, and Vegeta. Then when you beat him he transforms into his second form, which has 300,000 life and you continue to fight him until Piccolo shows up. Then Piccolo goes one-on-one with Freeza's second form and when Freeza loses again he transforms into his third form, which has 350,000 life. Once Freeza has transformed into his third form Vegeta, Gohan and Krillin join in to help Piccolo, and once Freeza loses AGAIN he transforms into his final form, which has 400,000 life, and you fight him until Goku arrives. Then Goku goes one-on-one with final form Freeza and drops a Spirit Bomb on him when you win. And then, if you meet the requirements for the [[MultipleEndings True Ending]], Goku goes Super Saiyan and fights [[TrueFinalBoss 100% Final Form Freeza]]. Twice. This whole sequence of bossfights takes no less than three hours. And [[BladderOfSteel you can't pause during battle]]. Fortunately the game is generous enough to allow you to save in the middle of this series of bossfights, once when Piccolo arrives and again when Goku arrives.

* Bosses in the arcade version of ''VideoGame/DoubleDragonII'' are in general much tougher than the first game, but Abore, the Andre The Giant {{ersatz}} in Mission 2 , takes the cake. It doesn't help that you fight two of him in the final stage.

** The Landshark and Shallow Sea / SeaLab X. It can take 6 hours to complete the latter with a full crew. On medium. The former takes around an hour to beat...with 20 other people attacking it.
** Kamila, the boss of Deadman's Shadow. While an entire Shallow Sea/Sealab run can take six hours on medium, just fighting Kamilia's Bloodlust form alone will usually take at least two hours, and that's if nobody wipes. Assuming everybody is Attuned, and everyone has their rings maxed to 12.0, an entire Bloodlust ''run'' can take as long as five hours, ''not counting'' time spent assigning buffs and time lost to disconnects and lag. If not everyone is Attuned, expect runs to last as long as eight hours or more, exclusive of buff assignments and time loss.

* ''VideoGame/EldenRing:
** The Fire Giant has a whopping 43,623 HP. Already this is an intimidating amount of HP, one of the highest in the game, but it gets worse when the uneven terrain makes it hard to hit his foot sometimes, and with his habit of rolling away. The second phase has him rip off his main weak spot of his exposed foot, but sadly, his hands and eyes are very hard to hit as a melee build, meaning the safer strategy is to hide behind him, meaning you do significantly less damage, and he rolls away even more now! Combine this with his attacks like his fireballs often forcing you to run away, and you’ll be here for a while.
** The Final Boss. Radagon, isn’t this, but unfortunately it is attached to the Elden Beast fight. Combined, they have less HP than the Fire Giant, but unlike the Fire Giant neither of them can be afflicted with Frostbite or Bleed, and both of them have high resistances to Poison and Scarlet Rot and all elemental damage on top of this, meaning there is less available to melt through them. While Radagon is a traditional-ish 1-on-1 duel fight, Elden Beast, on top of having most of the HP, generally consists of him teleporting away while he fires magic at you that forces you to be on the defensive. Unlike the Fire Giant, you do not get Torrent during the fight, meaning you will spend more time simply running into attack range. This combined makes for an agonisingly long fight that many people do not attempt without summons.

* Parodied (like every other video game trope) in ''VideoGame/TheAngryVideoGameNerdIIAssimilation'' with Sir Werepire. First he's a vampire, then a vampire werewolf, then a vampire werewolf knight, then his health bar refills and he comes back as a vampire werewolf knight ghost, and ''then'' he comes back as a vampire werewolf knight zombie. The Nerd loses his temper and just leaves the boss arena:

** The series' other {{Bonus Boss}}es are just as bad. From ''VideoGame/KingdomHeartsI'', we have the Ice Titan and [[VideoGame/FinalFantasyVII Sephiroth]]. The Ice Titan is a pain because the primary way to damage it is to deflect one of its attacks back at it, which as the fight goes on, it will do less and less, and often whilst you are in no position to be able to deflect. Sephiroth is easier to damage, but has a ridiculously large shield to whittle down before his health bar even begins to deplete, and has attacks which will almost kill you, even at full health. ''VideoGame/KingdomHeartsII'' has Sephiroth again, who has 15 health bars (the final boss has at most 7/8) and loves to do back-to-back [[HPToOne Heartless Angels]] and [[TeleportSpam Teleport Flashes]] before you can heal.

** ''VideoGame/Pikmin1'': The Emperor Bulblax has a buffed life meter that takes much longer than any other creature to go down.

Some bosses can be taken out pretty fast. Not these. For these, well, you'd best make sure your schedule is clear for the day.

* {{Self Imposed Challenge}}s are a big part of ''VideoGame/GodOfWar''. One such challenge in ''VideoGame/GodOfWarII'' involves using General Kratos on the hardest difficulty with no upgrades to weapons or magic. Almost every boss becomes a Marathon Boss due to the incredibly low damage Kratos deals in this mode, and the absurdly high damage he takes. For bonus points, some veterans complete the game [[{{UpToEleven}} using nothing]] but the starting Blades of Athena at Level 1, and ignoring chests.

* Tropicallo from ''VideoGame/LegendOfMana'': instead of taking damage like a regular boss, it loses a set fraction every time one of its two tendrils dies. One of them is an insanely tough attacking type tendril, the other casts magic and has a humongous self-destruct attack when detached. This gets turned UpToEleven in the [[NewGamePlus Nightmare and No Future modes]] -- it does rather more damage, but is still a cakewalk. Unfortunately, while it winds up with a hundred health bars, the amount of damage dealt to it with each tendril's death ''doesn't increase'', meaning that you will literally spend ''hours'' trying to put it out of its well-deserved misery. (Unless you turned off No Future mode before fighting it...)

** There's also Deathwing, the BigBad of Cataclysm on heroic. You first have to actually ''get'' to him while his Mooks, which include a boss battle fight you on the way there, which may or may not count, then you fight him. He's [[UpToEleven two individual boss battles]]. First you have to kill all but 2 of the tentacles on his back, which start at 4, then get him to flip over, killing the EliteMooks that spawn, ''then'' you kill the last tentacle, kite the mook around killing lesser mooks while whittling it's hp to 10% or so while pulling him over all the dead lesser mooks, to make him unstable, exploding and revealing the actual [[AttackItsWeakPoint weak point]] which is then attacked, it takes 2 tries to kill, so ''now'' you take out his final tentacle and repeat the explosion part all over again. If you done all that, Congratulations! There are now ''six'' tentacles and you have to repeat it again, then one last time with ''eight''. After that's all done, you have beaten the first boss battle with him. The second involves killing a large tentacle so it doesn't use it's Impale twice which deals Massive Damage, then killing his arm, which is clinging to the platform, which spawns waves of mooks that deal escalating damage once ''again'' forcing you to kill ''them'', all while deathwing occasionally blasts you with a big rock that deals a chunk of damage, then constantly deals damage, forcing you to kill ''that''. If you don't do all of this in short enough time, he finishes casting "Final Cataclysm" causing a NonstandardGameOver. Done? Good! You lose one of the 4 buffs and have to do it ''3 more times''. ''THEN'' comes the final bit, where he spawns unending waves of mooks, and does damage to everyone based on how much hp he is missing.

** The game has Yggralith Zero and Telethia Plume, who are fought in online squad missions. It's not too challenging for a properly outfitted team to bring their health bar down to zero -- but they each have several '''''million''''' health bars. At least you're not expected to finish them in one sitting, or finish them at all; beating one of these bosses is a worldwide event in which players from across the globe do what amounts to ScratchDamage on the boss in timed increments, in hopes that everyone's collective efforts will have the monster defeated before the event ends. The bad news? [[HealingFactor They recover]] '''[[HealingFactor hundreds of thousands of lifebars]]''' [[HealingFactor between event cycles.]] Each one has several hundred-thousand HP already, so multiply that by about '''10 million''', and that's the total HP these absurd beings have. That's easily in the ''[[SerialEscalation trillions]]'' range, and probably ''[[UpToEleven more.]]''

** Darm in ''VideoGame/YsIIAncientYsVanishedTheFinalChapter'' is also a really long boss fight, even with your EXP maxed out. Then there's his {{teleport spam}}ming and the constant rain of fireballs you must dodge.
** Arem, the BigBad of ''VideoGame/YsIVTheDawnOfYs'', takes it UpToEleven. He has three lifebars (the last form fortunately is a ClippedWingAngel), a laundry list of powerful attacks, is hard to hit, your attacks only do minuscule damage even with max EXP, and he can regenerate his HP.

* Bosses in ''VideoGame/TheLegendOfDragoon'' are all like this due simply to the mechanics of the game. If you haven't played it, magic is outrageously rare and is for use on bosses only. Only two characters have healing magic at all (Shana/Miranda and Meru), but Shana and Miranda are ''so'' much better at it than Meru and Boss battles with Shana and Miranda take ''forever'', and the item limit is quite low. The way you heal is that every time you defend, you heal 10% of your maximum health. It definitely adds length to every boss fight. This isn't to say anything about the FinalBoss, which can easily take an ''hour or two'' if you're characters aren't grossly overlevelled.

* Parodied (like every other video game trope) in ''VideoGame/TheAngryVideoGameNerdIIAssimilation'' with Sir Werepire. First he's a vampire, then a vampire werewolf, then a vampire werewolf knight, then his health bar refills and he comes back as a vampire werewolf knight ghost, and ''then'' he comes back as a vampire werewolf knight zombie. The Nerd looses his temper and just leaves the boss arena:

* The MiniBoss battles during the Bandit Spider challenges in ''VideoGame/{{Okami}}'' are this, since both the minibosses involved ''and'' the enemies have their HP significantly buffed. Among the regular bosses, there's Orochi and [[spoiler:Yami]] as well.

** The normal final boss, Jeane, also takes a very long time to wear down, especially on Bitter difficulty.

** Pyribbit in ''VideoGame/KirbyTripleDeluxe'', as he starts to spend a lot of time in the background during the second phase and spends ''very'' little time vulnerable with he does show up to be hit. If you take a hit during that time (and you likely will, as every time he comes back to Kirby's platform, it's accompanied by an attack) and spend most of it stunned, the fight will only take longer. Made even worse in [[spoiler:Dedede Tour]], where you not only have to fight Pyribbit EX, but you have to be quick about it, too.

* Ganondorf in ''VideoGame/TheLegendOfZeldaTwilightPrincess'' - after going through a gruelling route to the top of Hyrule Castle, with ''three'' [[BossInMooksClothing Darknuts]] to face, including one right by the entrance to the boss room, you have to go up against Ganondorf himself. First, he possesses Zelda, as a TennisBoss with a nasty habit of stabbing you and using [[LightIsNotGood light magic to fry the floor around you]]. Then, he turns into the giant beast, Ganon, who you either have to be good at shooting in the crystal above his eyes or use the Wolf Link form with Midna to wrestle to the ground before going for his belly. ''Then'' he goes riding across Hyrule Plain and you have to keep him directly ahead of you so Zelda can stun him with Light Arrows, all while dodging his summoned ghost riders and avoiding his occasional opportunistic attacks, and ''THEN'' you finally face off in a brutal one-on-one swordfight.

** First is Rumi, the penultimate post-game boss. She has a ridiculous SIX health bars (The final boss of the game had three forms, but each was only only health bar), and that's only part of the reason why she takes so long. For every lifebar except the first, she starts by taking the battle into a flying section, which severely limits your combat options, and when that is over, she puts the [[AttackReflector 99Reflect]] buff on herself for the duration of one attack (and her attacks are pretty long) which makes it impossible to deal relevant damage to her while it is up. Finally, she also has a permanent buff that cuts all damage you do to her by half. Put everything together, and you're in for an exhausting fight.

** First is Rumi, the penultimate post-game boss. She has a ridiculous SIX health bars (The final boss of the game had three forms, but each was only only lifebar), and that's only part of the reason why she takes so long. For every lifebar except the first, she starts by taking the battle into a flying section, which severely limits your combat options, and when that is over, she puts the [[AttackReflector 99Reflect]] buff on herself for the duration of one attack (and her attacks are pretty long) which makes it impossible to deal relevant damage to her while it is up. Finally, she also has a permanent buff that cuts all damage you do to her by half. Put everything together, and you're in for an exhausting fight.