History ThatOneBoss / Terraria

* Wall of Flesh. If you don't prepare yourself in a ridiculous manner before the fight, you will have a LOT of trouble. First, you have to contend with the Hungry, mouths on tentacles that do ridiculous melee damage and become flying critters when killed, forcing you to kill them twice. For added annoyance, they respawn on Expert. They make ranged weapons a problem to use (unless you use Meteor Bullets or Unholy Arrows). If you get past that, you still have to deal with the Wall itself, which has very high health and uses BeamSpam from both eyes with increasing frequency as you do damage. On top of that, it accelerates as it takes damage; on its last legs, the Wall is actually faster than the player at full sprint. NO strategy will assure success against that freaking wall. Which makes coming back with Hallowed Armor, the Megashark, Crystal Bullets, and Excalibur (or, heaven forbid the [[InfinityPlusOneSword Zenith]]) for round 2 (or whatever number fight it is) all the more satisfying. Adding to this is the fact that it's prone to bugs. It may accidentally spawn heading the wrong way, which is pretty much instant death because any prepared player will summon it at the far end of the map. It can also spawn much further down than it's supposed to, making the world-spanning bridge you're basically required to build if you don't want to spend 90% of the fight swimming in lava or jumping over pits and structures useless. There's a reason why the characters' page says there's no middle ground - you're either overprepared or dead.

* Wall of Flesh. If you don't prepare yourself in a ridiculous manner before the fight, you will have a LOT of trouble. First, you have to contend with the Hungry, mouths on tentacles that do ridiculous melee damage and become flying critters when killed, forcing you to kill them twice. For added annoyance, they respawn on Expert. They make ranged weapons a problem to use (unless you use Meteor Bullets or Unholy Arrows). If you get past that, you still have to deal with the Wall itself, which has very high health and uses BeamSpam from both eyes with increasing frequency as you do damage. On top of that, it accelerates as it takes damage; on its last legs, the Wall is actually faster than the player at full sprint. NO strategy will assure success against that freaking wall. Which makes coming back with Hallowed Armor, the Megashark, Crystal Bullets, and Excalibur (or, heaven forbid the [[InfinityPlusOneSword Terra Blade]]) for round 2 (or whatever number fight it is) all the more satisfying. Adding to this is the fact that it's prone to bugs. It may accidentally spawn heading the wrong way, which is pretty much instant death because any prepared player will summon it at the far end of the map. It can also spawn much further down than it's supposed to, making the world-spanning bridge you're basically required to build if you don't want to spend 90% of the fight swimming in lava or jumping over pits and structures useless. There's a reason why the characters' page says there's no middle ground - you're either overprepared or dead.

* Surprisingly, [[WarmupBoss the Eye of Cthulhu]] is this on Expert, mostly due the extra-fast charge it'll start using in its second phase. It's incredibly fast, deals obnoxiously high damage, and will likely be near-impossible to avoid at the level you're supposed to be fighting the Eye at. When it's at critical health, it'll be doing it constantly - good luck hitting it with arrows.

* Of all the Celestial Pillars, the Solar Pillar is infamous for how hard it is, and on Master difficulty it's absolutely sadistic, turning into this. The Solar Pillar is designed to enforce melee with its special mechanics, but melee is suicide on Master difficulty due to the sheer amount of damage everything does - Everything will kill you in 2-3 hits. If you bring a ranged weapon or a magic weapon, Selenians will reflect your projectiles back at you so you hit yourself. If you try flying or multi-jumping, Crawltipedes will spawn and seek you out no matter how fast you fly or how far away you go and will deal 450-500 damage if they hit you. If you stand on the ground, you will have to deal with Srollers launching themselves at you from offscreen at incredible speeds. Try to hide behind blocks? Corites ignore them. And the pillar itself will randomly throw a half-dozen fireballs at you while you do all this. The greatest irony is that this supposedly melee-themed pillar has the largest, fastest, and most frequent 'projectiles' of any of them because of all the mobs throwing themselves at you. Most peoples' advice for beating the Solar Pillar on Master is just 'Keep throwing yourself into it and respawning and it will eventually die.' It's often considered harder than the ''Moon Lord.''

* The Destroyer has become notorious as an incredibly difficult mech boss, ever since it got buffed. It was briefly nerfed in 1.2 reducing its defense, damage, and health, but then 1.2.3 came along and reversed the nerf big time, raising its stats even higher than they were before. Additionally, there's less healing for you during the fight (since probes now only drop hearts 33% of the time instead of 100%) and it's completely immune to all debuffs! Most strategies that would have instantly killed Destroyer before are now significantly less useful, and you'll have to contend with its [[DamageSpongeBoss massive health bar]], BeamSpam, and storm of minions without those prior tricks. However, [[AchillesHeel piercing weapons (most infamously the Daedalus Stormbow/Holy Arrows combo) can still take it down very quickly]], and targeting its coiled segments when it first spawns can outright end the fight in seconds.

* Duke Fishron, introduced in version 1.2.4. [[LightningBruiser He's extremely fast and powerful, and has a minimum of 50,000 HP to boot]]. Fighting him in a small-medium sized arena is downright suicidal, as he will create huge tornadoes that not only shoot high-speed, high damaging sharks at a very fast rate, but will also limit the player's movements. Think it can't get any worse? He TurnsRed when low on HP becoming even faster, 1.5x as painful, and more erratic. ButWaitTheresMore -- in Expert Mode, he has a ''third'' phase when on his last legs where he fogs the entire arena, turns invisible and then appears to charge at you for massive damage from various angles; the only way to tell where he'll appear is ByTheLightsOfTheirEyes. In 1.3 (the same update that introduced Expert Mode), he got buffed even further--he will get pissed and now ''repeatedly'' use his fast charging attack if he leaves the ocean.
* The Empress of Light, introduced in 1.4, is essentially a Touhou-style BulletHell boss with a whopping '''70,000 HP''' ''at minimum on Normal''. Not only is she [[LightningBruiser fast as hell and extremely damaging]], she'll flood the screen with all manner of projectile attacks, making it hard to navigate through even with flight, and even has homing bullets in her arsenal. Oh, and if the fight goes into daytime, her bullets essentially are a OneHitKill, so you ''cannot'' afford to get grazed by one - worse still, ''beating her at day is required to get one of her particular drops''. You're going to need a gigantic arena to account for all the movement and teleportation she'll do, or you'll more than likely get destroyed. And woe betide you if you're a summoner, because the Empress is even more merciless to summon builds due to most minions being ''unable to hit her in the first place''.

* The Pumpkin Moon. It starts out simple, with [[TheGoomba Scarecrows]], [[MightyGlacier Splinterlings]], and [[LightningBruiser Hellhounds]] that can be fairly easily handled with good crowd control weapons. Then you hit wave 4 and the [[WhenTreesAttack Mourning Wood]] shows up. It's got 12,000 HP, it fires a huge spray of fire that sticks around on the ground for a few seconds and does huge damage, and it's surprisingly fast. It only gets worse from there.
* The Frost Moon. It's the Pumpkin Moon taken to eleven. The first few enemies like [[TheGoomba Zombie Elves]] and Gingerbread men can be handled with ease with Pumpkin Moon loot, up until you hit Wave 4 and the Everscreams come out with 13,000 HP, being a harder version of the Mourning Wood. Later, you have to fight [[BadSanta Santa-NK1]], which fires very powerful missiles and presents, and boasts 18,000 HP. Even later, from Wave 12 onwards, you fight the IceQueen. With 34,000 HP, she is pretty much Pumpking on crack, flying everywhere and firing ice shards. It gets hectic really fast; good luck getting past wave 12 on your own. To put it? Some people consider the Ice Queen to be ''tougher'' than Duke Fishron (see above).
* The Martians are already a piece of work, but the boss of the event, the Martian Saucer, turns it up. It has a hefty amount of health split over its 5 parts, is faster than it looks, and deals extremely high damage with a wide variety of hard-to-dodge attacks, including a death ray that hits hard, passes through walls post-Journey's End update, and can chunk you for up to 200 damage on Expert. And on Expert, if you think you've got it on the ropes after taking down its weapons to disable its BeamSpam and MacrossMissileMassacre attacks, then think again, because not only does it now have a defense of 100, all but nullifying low-power weapons, it'll dash all over the place while spamming its WaveMotionGun, which now deals over ''double'' the damage it used to and is liable to deliver two-hit kills.
* The Old One's Army, especially at Tier 3, becomes this on Master difficulty. While challenging but doable on Normal and Expert, the increases to enemy hit points, defense, and damage on Master turns the Old One's Army into a nigh-unstoppable tide of hit points that even end-game weapons have difficulty chewing through, and attacks from almost anything will kill the crystal in seconds and the player in two or three hits. Since the event is a pure damage race in a very limited space, turning it up to Master suddenly makes it require a systematic plan of attack and a generous helping of cheese to defeat. Woe unto any Master Mode player who forgot to farm Defender Medals to get a ballista staff before Tier 3, since by then it's basically impossible without a hair-pulling amount of grinding.

* Skeletron can be a pain to beat. First off, he has significantly more health than the other Pre-Hardmode bosses, and boasts two CognizantLimbs which will flail around and do respectable amounts of damage on hit. Secondly, he resists the majority of DamageOverTime debuffs, so unless you made Frostburn Arrows, you're tough out of luck. Thirdly, he can perform a head charge which is not only difficult to dodge at this point in the game, but can easily stunlock you and hammer you for a ridiculous amount of damage. Not to mention that the way his spawning works means that he's guaranteed to spawn on top of you, nailing you for cheap damage if you're unlucky. Should dawn arrive due to poor timing or the fight taking too long, Skeletron will instantly kill you. All of this is cranked UpToEleven in Expert Mode - not only does he have more health than ''Normal Wall of Flesh'', he inflicts StatusEffects, is NighInvulnerable until you take down both his hands, and can vomit out dangerous homing projectiles at an alarming rate, all the while massively increasing the speed of his aforementioned head charge.

* The Twins are a DualBoss that can easily box you in with little effort thanks to their huge hitboxes, incredibly fast speed which makes dodging them very tricky, and their TurnsRed mode that takes their attacks UpToEleven. Spazmatism has a cursed flame attack in his panic mode with a ridiculously huge hitbox, and charges at you with barely a second to dodge. Meanwhile, Retinazer's EyeBeams start getting [[BeamSpam spammed]] to BulletHell levels. The only reliable strategies many players can cook up is "make a giant sky bridge that extends all the way across the world, shoot at Spazmatism while running away on a fast mount", or "use Gravitation potion and keep switching gravity as you run away from the Twins and shoot at Spazmatism".

* The Frost Moon. It's [[UpToEleven The Pumpkin Moon Taken to Eleven.]] The first few enemies like [[TheGoomba Zombie Elves]] and Gingerbread men can be handled with ease with Pumpkin Moon loot, up until you hit Wave 4 and the Everscreams come out with 13,000 HP, being a harder version of the Mourning Wood. Later, you have to fight [[BadSanta Santa-NK1]], which fires very powerful missiles and presents, and boasts 18,000 HP. Even later, from Wave 12 onwards, you fight the IceQueen. With 34,000 HP, she is pretty much Pumpking on crack, flying everywhere and firing ice shards. It gets hectic really fast; good luck getting past wave 12 on your own. To put it? Some people consider the Ice Queen to be ''tougher'' than Duke Fishron (see above).
* The Martians are already a piece of work, but the boss of the event, the Martian Saucer, turns it UpToEleven. It has a hefty amount of health split over its 5 parts, is faster than it looks, and deals extremely high damage with a wide variety of hard-to-dodge attacks, including a death ray that hits hard, passes through walls post-Journey's End update, and can chunk you for up to 200 damage on Expert. And on Expert, if you think you've got it on the ropes after taking down its weapons to disable its BeamSpam and MacrossMissileMassacre attacks, then think again, because not only does it now have a defense of 100, all but nullifying low-power weapons, it'll dash all over the place while spamming its WaveMotionGun, which now deals over ''double'' the damage it used to and is liable to deliver two-hit kills.

Note: Because of the sandbox nature of Terraria, it is very much possible to cheese many of the bosses on this list with proper prep-work. As such, bosses listed here are based on the bare minimum amount of setup needed to have a chance at fighting them. ''Do not list ways to cheese bosses on this list''; [[Administrivia/WalkthroughMode TV Tropes is not GameFAQs]].

* Skeletron can be a pain to beat. First off, he has significantly more health than the other Pre-Hardmode bosses, and boasts two CognizantLimbs which will flail around and do respectable amounts of damage on hit. Secondly, he resists the majority of DamageOverTime debuffs, so unless you made Frostburn Arrows, you're tough out of luck. Thirdly, he can perform a head charge which is not only difficult to dodge at this point in the game, but can easily stunlock you and hammer you for a ridiculous amount of damage. Not to mention that the way his spawning works means that he's guaranteed to spawn on top of you, nailing you for cheap damage if you're unlucky. Should dawn arrive due to poor timing or the fight taking too long, Skeletron will instantly kill you. All of this is cranked UpToEleven in Expert Mode - not only does he have more health than ''Normal Wall of Flesh'', he inflicts StandardStatusEffects, is NighInvulnerable until you take down both his hands, and can vomit out dangerous homing projectiles at an alarming rate, all the while massively increasing the speed of his aforementioned head charge.

* The Destroyer has become notorious as an incredibly difficult mech boss, ever since it got buffed. It was briefly nerfed in 1.2 reducing its defense, damage, and health, but then 1.2.3 came along and reversed the nerf big time, raising its stats even higher than they were before. Additionally, there's less healing for you during the fight (since probes now only drop hearts 33% of the time instead of 100%) and it's completely immune to all debuffs! Most strategies that would have instantly killed Destroyer before are now significantly less useful, and you'll have to contend with its [[DamageSpongeBoss massive health bar]], BeamSpam, and storm of minions without those prior tricks [[AchillesHeel (although piercing weapons can still take it down very quickly)]].

* Skeletron Prime if you're trying to beat him solo. He has four arms, each of which has its own abilities and can do a fair amount of damage, and his head gains defense when it spins instead of losing it like the last version did. His high health and arms will soak up damage to near the end of the night, and if you don't beat him by then, he becomes practically unbeatable and gets a OneHitKO attack.

* The Martians are already a piece of work, but the boss of the event, the Martian Saucer, turns it UpToEleven. It has a hefty amount of health split over its 5 parts, is faster than it looks, and deals extremely high damage with a wide variety of hard-to-dodge attacks, including a death ray that hits hard, passes through walls post-Journey's End update, and can chunk you for up to 200 damage on Expert. And on Expert, if you think you've got it on the ropes after taking down its weapons to disable its BeamSpam and MacrossMissileMassacre attacks, then think again, because not only does it now have defense of 100, all but nullifying low-power weapons, it'll dash all over the place while spamming its WaveMotionGun, which now deals over ''double'' the damage it used to and is liable to deliver two-hit kills.

[[folder: Pre-Hardmode Bosses]]

[[folder: Hardmode Bosses]]

[[folder: Events]]

[[/folder]]

[[folder: General]]
* The majority of bosses in Terraria have the potential to be this. In general, the game suffers from slight UnexpectedGameplayChange and you have to be CrazyPrepared to win most of the boss fights: make all the potions to enhance your damage and defense, get the best armor and weapons possible, build an arena, and plan every step of the way. Sandbox game? Nah, it's a strategy now. No, you can't try just running circles around it. It's not gonna work.
** In Expert Mode, all the bosses become this, as they're twice as strong while you aren't. This is especially bad in the early game, as your options are limited because the bosses are holding the items you need to progress.
[[/folder]]