History DemonicSpiders / Runescape

** The worst of the lot are the Death Lotus Rogues. Their normal attack is weak, but their special attack is ferocious. When activated, they will spin around, hurling projectiles everywhere for ''extremely'' rapid ranged hits. This has a much wider range than the sellswords specials, the individual hits are strong enough to kill in seconds ''even through prayer'', and if you try to run away, [[YouWillNotEvadeMe they can follow you while still doing the special]]. If you can't stun or kill these guys quickly, the recommended option is to teleport out to avoid a costly death.

** The Hanto Sellswords hit hard with melee, and if they yell "Die by the blade!", get far away from them, because they will use a powerful spinning attack that inflicts rapid and heavy hits on anyone nearby, making it easy to die if one is inattentive (with an [[HaveANiceDeath achievement]] if you do get killed by the special).

** The first elite Slayer monster, Living Wyverns, are the bane of even the best players. They are aggressive, inflict gobsmacking amounts of damage with their attacks (even more if you do not apply a special potion to protect you from their breath), can inflict a very damaging [[PoisonousPerson poison status]], and are accompanied by a very annoying environmental mechanic. See, the underground cave they reside in is incredibly cold. If you allow yourself to become too cold, you start getting stunned for 8-10 seconds at a time, preventing you from attacking, healing, or teleporting. This can be countered temporarily by lighting the fires in the cave and using anti-stun abilities, but if you are caught off guard and your abilities are on cooldown, you may have no choice but to watch your helpless character get [[CurbStompBattle murdered]].

** Wilderness Bandits. It's not the fact that they use abilities so much as the fact that you can't set foot in their camp without being [[ZergRush Zerg Rushed]] (and likely killed) unless you're skulled (and by extension, opted into [=PvP=]. Their leaders are even armed with the completed weapons from lava strykewyrms. Worst of all, their drops are absolutely pitiful if you somehow manage to kill them. Of course, this ''is'' the Wilderness after all, so in addition to the potential of being attacked by [[PlayerKilling PKers]] due to being opted into [=PvP=], you have the added threat of monster ambushes and heavy-hitting volcanic projectiles. Have fun.

* Killerwatts are an almost literal example of a LightningBruiser. These Slayer foes have dangerous melee and ranged attacks that can hit as hard as the above-mentioned dark wizards, but ''twice as fast''. And if you forget to wear a special pair of boots, their attacks hit even ''harder'', to the point that surviving the barrage of damage, especially at the levels you'll probably be fighting them at, becomes nigh-impossible. To top it all off, the drops are mediocre and consist mostly of low-level runes, herbs, and occasional alchables.

* Lizardmen in general are already dangerous enough thanks to their hard-hitting, poisonous ranged and melee attacks and tendency to gang up on you, but lizardman ''shamans'', their high-level counterpart, pull absolutely no punches. Not only do shamans hit even harder than their lesser brethren (both with their regular attacks and poison), but they also throw some nasty and hard-to-avoid special attacks into the mix. And of course, they'll gang up on you like (and often with) other lizardmen, making survival very difficult. Oh, and you can't even ''attack'' them until you've earned 100% favour with Shayzien, which is a chore in and of itself. To top it all off, they're a fairly common Slayer assignment. On the flip side, if you're brave enough to defeat a shaman, you'll have a 1 in 5000 chance of getting yourself the highly coveted Dragon Warhammer.

* Waterfiends. It's bad enough that they have accurate, hard-hitting ranged and magic attacks, but what makes them frustrating to kill is their obscene defence against anything that isn't a crushing attack. Most good melee weapons on ''Old School'' tend to be stab or slash weapons. Decent crush weapons are few and far in between, and the better ones cost quite a lot, while still being worse than similarly-levelled weapons like the Dragon Scimitar and Abyssal Whip. Not helped at all by their average-at-best drop table, inconvenient locations, and the fact that they are a very common assignment from high-level Slayer masters.

* Lizardmen in general are already dangerous enough thanks to their hard-hitting, poisonous ranged and melee attacks and tendency to gang up on you, but lizardman shamans, their high-level counterpart, pull absolutely no punches. Not only do shamans hit even harder than their lesser brethren, but they also throw some nasty and hard-to-avoid special attacks into the mix. And of course, they'll gang up on you like (and often with) other lizardmen, making survival very difficult. Oh, and they're a fairly common Slayer assignment as well. At least if you're brave enough to defeat a shaman, you'll have a 1 in 5000 chance of getting yourself the highly coveted Dragon Warhammer.

** Wilderness Bandits. It's not the fact that they use abilities so much as the fact that you can't set foot in their camp without being [[ZergRush Zerg Rushed]] (and likely killed) unless you're skulled (and by extension, opted into PvP. Their leaders are even armed with the completed weapons from lava strykewyrms. Worst of all, their drops are absolutely pitiful if you somehow manage to kill them. Of course, this ''is'' the Wilderness after all, so in addition to the potential of being attacked by [[PlayerKilling PKers]] due to being opted into [=PvP=], you have the added threat of monster ambushes and heavy-hitting volcanic projectiles. Have fun.

** Iorwerth and Cadarn elves in Prifddinas. Unlike most ability-using monsters, their adrenaline meter is constantly locked at 50%, enabling them to use threshold abilities [[TheComputerIsACheatingBastard without having to build it up]]. It's not terribly uncommon to attack a Cadarn Magus and have him immediately stunlock you with an Asphyxiate combo. Worse yet, while the elves are not aggressive, it's not horribly uncommon for high level players with access to Morvran (the game's second highest-levelled Slayer master) to teleport to him while still under the effects of their aggression potions from a prior task, and immediately get [[ZergRush piled]] ([[CurbStompBattle and likely murdered]]) in the process of trying to get a new task ([[https://www.deviantart.com/prezleek/art/Agression-Impression-723939093 Observe]]). At least there are several banks and even a prayer altar within walking distance.

* The infamous Dark Wizards south of Varrock, the ultimate bane to new players' existence. Aggressive monsters with surprisingly strong magic attacks, they can kill any player fresh off Tutorial Island in as few as two hits. Newcomers might head up to Varrock for the first time, only to be picked off by the wizards on the way there and lose their tutorial gear. Making matters worse, their combat level is [[MinMaxing deceptively low for the damage they deal]], and they are even capable of giving higher-levelled players a run for their money.
* Not as deadly as the dark wizards, but still a fair threat, are the Draynor jail guards. Even though they only hit half as hard as the aforementioned dark wizards, it's still enough to drop a new player in four hits. Compounding matters further, they are aggressive and located in a multicombat area less than a minute away from Lumbridge, the starting town. To new players just starting out, they can be a nightmare to deal with, but at higher levels, they decrease to GoddamnedBats status. In fact, medium-level players may even exploit their aggression and use them for training, particularly in free-to-play.

** Forgotten Mages. Trying to get past all of those enemies in that one room with your Shadow Silk Hood? Good luck trying to pull it off without the hood's effects as they will promptly reveal you to the other monsters, who will proceed to ZergRush you. It certainly doesn't help that they can bind you in place and lower your melee stats, making it frustrating to kill them with melee. Necromancers are similar, except instead of trying to bind you, they instead summon zombies to attack with melee.
** Reborn Mages on Warped floors. In addition to being able to drain your stats and remove your Shadow Silk Hood's effects (if you have one) like Forgotten Mages, they can also summon hard-hitting Reborn Warriors that attack with melee. As if this wasn't enough, both Reborn Mages and Reborn Warriors can even ''follow you into other rooms''.

** The second elite Slayer monster [[WolverineClaws Ripper]] [[LightningBruiser Demons]], mainly for their ability to [[OneHitKill instakill you]], but for other reasons as well. They telegraph their DeathFromAbove attack and it is avoidable, but if you don't get right back into their melee reach after avoiding it, they will ''[[YouWillNotEvadeMe drag you towards them]]'' and hit you with a very painful melee bleed. It's bad enough in and of itself, but if your health drops below 35%, all of the other demons in the vicinity will ZergRush you, likely [[CurbStompBattle dropping you in seconds]] unless you can teleport out. On top of that, even if you do manage to kill one, it will start spinning around wildly [[LastDitchMove in a final effort to try and kill you]], causing rapid melee damage as it dies; thankfully, the Deflect Melee curse with the Devotion ability blocks all of the damage, if only for ten seconds. Oh, it should probably be mentioned that they can be found in the Wilderness too, and are one of the potential mobs that can spawn in an ambush when it occurs.

** The last elite Slayer monster, Acheron mammoths, are probably the toughest of the four. Though somewhat slow to move, [[MightyGlacier they have a truckload of health and high defence against anything that isn't a stabbing weapon]], and can use heavy hitting melee and ranged attacks, including a selection of combat abilities. They also have a [[ThatOneAttack special charge attack]] that can deal upwards of 7500 damage, ''multiple times in a row'' (though it is telegraphed and avoidable). To make matters worse, they have an "honour" mechanic while you're fighting them: if you try running out of the reach of their melee attacks (or even trying to avoid their ranged attacks), they will disable your prayers, and if you try ranging or maging them, their ranged attacks will gain a secondary effect that constantly stunlocks you, effectively mandating the use of melee to kill them.

* Revenants, powerful Wilderness-dwelling ghosts that can attack from all three corners of the combat triangle. They will ZergRush you as soon as you enter their lair, the Forinthry Dungeon (in ''3'') or the Revenant Caves (in ''Old School''), which can be deadly considering they can hit almost as hard as (and in some cases harder than) players of similar combat level (though in ''3'' there is an item you can use to make them non-aggressive, and ''Old School'' has a similar item that dramatically reduces their damage output). They also have the ability to rapidly heal themselves when their health drops low, so you'll probably spend more time killing them than you would want to. Of course, this ''is'' the Wilderness so you have the added threat of environmental hazards and monster ambushes (in ''3'') and [[PlayerKilling PKers]] (mainly in ''Old School'', but also in ''3'' if you're opted into PvP in the latter). Oh, and they can also spawn in the aforementioned monster ambushes in ''3''. They were worse when they were originally introduced into the Wilderness as a replacement for [=PKers=] following the infamous 12-10-07 update to remove [[PlayerVersusPlayer PvP]] in the Wilderness. Not only did they roam all around the Wilderness, but they could teleblock and bind you in addition to their healing powers and high damage output, not to mention that if you could succesfully kill them, their drops were much worse than what they currently are (their original best drop was a measly ''dragon scimitar''). Thankfully, when PlayerKilling returned about three years later, they were contained in the aforementioned Forinthry Dungeon, and also lost their bind and teleblock powers.

* Lava strykewyrms are considerably harder than any of the other three types of strykewyrm, and have much more difficult mechanics to deal with, such as dragging you towards them. Like revenants, these monsters are also exclusive to the Wilderness, which in this game means you have to worry about prayer-flicking to avoid a heavy-hitting projectile from the north-eastern volcano, or occasionally deal with a gang of very high-level mobs. And [[PlayerKilling PKers]] too, if you're opted into PvP. On top of that, there is also a [[EliteMook stronger version]], the [=WildyWyrm=], that can appear at complete random, but hits much higher and has ''a million'' life points. Killing them, especially the [=WildyWyrm=], is a very risky gamble no matter what your approach - if you use cheap gear, you will struggle just to get one kill, but if you wear stronger gear, you become a tempting target for [=PKers=]. It's also not helped by the fact that they're one of the 151 monsters listed in the [[MonsterCompendium Slayer Codex]], if you intend to complete it as a requirement to trim the Completionist Cape.

** Wilderness Bandits. It's not the fact that they use abilities so much as the fact that you can't set foot in their camp without being [[ZergRush Zerg Rushed]] (and likely killed) unless you're skulled (and by extension, opted into PvP. Their leaders are even armed with the completed weapons from lava strykewyrms. Worst of all, their drops are absolutely pitiful if you somehow manage to kill them. Of course, this ''is'' the Wilderness after all, so in addition to the potential of being attacked by PKers due to being opted into PvP, you have the added threat of monster ambushes and heavy-hitting volcanic projectiles. Have fun.

* Revenants, powerful Wilderness-dwelling ghosts that can attack from all three corners of the combat triangle. They will ZergRush you as soon as you enter their lair, the Forinthry Dungeon (in ''3'') or the Revenant Caves (in ''Old School''), which can be deadly considering they can hit almost as hard as (and in some cases harder than) players of similar combat level (though in ''3'' there is an item you can use to make them non-aggressive, and ''Old School'' has a similar item that dramatically reduces their damage output). They also have the ability to rapidly heal themselves when their health drops low, so you'll probably spend more time killing them than you would want to. Of course, this ''is'' the Wilderness so you have the added threat of environmental hazards and monster ambushes (in ''3'') and [[PlayerKilling PKers]] (mainly in ''Old School'', but also in ''3'' if you're opted into [=PvP=] in the latter). Oh, and they can also spawn in the aforementioned monster ambushes in ''3''. They were worse when they were originally introduced into the Wilderness as a replacement for [=PKers=] following the infamous 12-10-07 update to remove [[PlayerVersusPlayer PvP]] in the Wilderness. Not only did they roam all around the Wilderness, but they could teleblock and bind you in addition to their healing powers and high damage output, not to mention that if you could succesfully kill them, their drops were much worse than what they currently are (their original best drop was a measly ''dragon scimitar''). Thankfully, when PlayerKilling returned about three years later, they were contained in the aforementioned Forinthry Dungeon, and also lost their bind and teleblock powers.

* Lava strykewyrms are considerably harder than any of the other three types of strykewyrm, and have much more difficult mechanics to deal with, such as dragging you towards them. Like revenants, these monsters are also exclusive to the Wilderness, which in this game means you have to worry about prayer-flicking to avoid a heavy-hitting projectile from the north-eastern volcano, or occasionally deal with a gang of very high-level mobs. And PKers too, if you're opted into PvP. On top of that, there is also a [[EliteMook stronger version]], the [=WildyWyrm=], that can appear at complete random, but hits much higher and has ''a million'' life points. Killing them, especially the [=WildyWyrm=], is a very risky gamble no matter what your approach - if you use cheap gear, you will struggle just to get one kill, but if you wear stronger gear, you become a tempting target for [=PKers=]. It's also not helped by the fact that they're one of the 151 monsters listed in the [[MonsterCompendium Slayer Codex]], if you intend to complete it as a requirement to trim the Completionist Cape.

** Wilderness Bandits. It's not the fact that they use abilities so much as the fact that you can't set foot in their camp without being [[ZergRush Zerg Rushed]] (and likely killed) unless you're skulled (and by extension, opted into [=PvP=]. Their leaders are even armed with the completed weapons from lava strykewyrms. Worst of all, their drops are absolutely pitiful if you somehow manage to kill them. Of course, this ''is'' the Wilderness after all, so in addition to the potential of being attacked by PKers due to being opted into PvP, you have the added threat of monster ambushes and heavy-hitting volcanic projectiles. Have fun.

* Revenants, powerful Wilderness-dwelling ghosts that can attack from all three corners of the combat triangle. They will ZergRush you as soon as you enter their lair, the Forinthry Dungeon (in ''3'') or the Revenant Caves (in ''Old School''), which can be deadly considering they can hit almost as hard as (and in some cases harder than) players of similar combat level (though in ''3'' there is an item you can use to make them non-aggressive, and ''Old School'' has a similar item that dramatically reduces their damage output). They also have the ability to rapidly heal themselves when their health drops low, so you'll probably spend more time killing them than you would want to. It certainly doesn't help that you can be attacked by [[PlayerKilling Player Killers]] at any time, and given how valuable some of their drops are, [[ParanoiaFuel you're very likely to encounter a PKing team there at some point]]. They were worse when they were originally introduced into the Wilderness as a replacement for [=PKers=] following the infamous 12-10-07 update to remove [[PlayerVersusPlayer PvP]] in the Wilderness. Not only did they roam all around the Wilderness, but they could teleblock and bind you in addition to their healing powers and high damage output, not to mention that if you could succesfully kill them, their drops were much worse than what they currently are (their original best drop was a measly ''dragon scimitar''). Thankfully, when PlayerKilling returned about three years later, they were contained in the aforementioned Forinthry Dungeon, and also lost their bind and teleblock powers.

* Lava strykewyrms are considerably harder than any of the other three types of strykewyrm, and have much more difficult mechanics to deal with, such as dragging you towards them. Like revenants, these monsters are also exclusive to the Wilderness, [[ParanoiaFuel putting you at constant risk of PKers attacking.]] On top of that, there is also a [[EliteMook stronger version]], the [=WildyWyrm=], that can appear at complete random, but hits much higher and has ''a million'' life points. Killing them, especially the [=WildyWyrm=], is a very risky gamble no matter what your approach - if you use cheap gear, you will struggle just to get one kill, but if you wear stronger gear, you become a tempting target for [=PKers=]. It's also not helped by the fact that they're one of the 151 monsters listed in the [[MonsterCompendium Slayer Codex]], if you intend to complete it as a requirement to trim the Completionist Cape.

** Wilderness Bandits. It's not the fact that they use abilities so much as the fact that you can't set foot in their camp without being [[ZergRush Zerg Rushed]] (and likely killed) unless you're skulled. Their leaders are even armed with the completed weapons from lava strykewyrms. Worst of all, their drops are absolutely pitiful if you somehow manage to kill them. Of course, this ''is'' the Wilderness after all, so you also have the added threat of [=PKers=]. Have fun.

** The first elite Slayer monster, Living Wyverns, are the bane of even the best players. They are aggressive, inflict gobsmacking amounts of damage with their attacks (even more if you do not apply a special potion to protect you from their breath), can inflict a very damaging [[PoisonousPerson poison status]], and are accompanied by a very annoying environmental mechanic. See, the underground cave they reside in is incredibly cold. If you allow yourself to become too cold, you start getting stunned for 8-10 seconds at a time, preventing you from attacking, healing, or teleporting. This can be countered temporarily by lighting the fires in the cave and using anti-stun abilities, but if you are caught off guard you may have no choice but to watch your helpless character get [[CurbStompBattle murdered]].
** The second elite Slayer monster [[WolverineClaws Ripper]] [[LightningBruiser Demons]], mainly for their ability to [[OneHitKill instakill you]], but for other reasons as well. They telegraph their DeathFromAbove attack and it is avoidable, but if you don't get right back into their melee reach after avoiding it, they will ''[[YouWillNotEvadeMe drag you towards them]]'' and hit you with a very painful melee bleed. It's bad enough in and of itself, but if your health drops below 35%, all of the other demons in the cave will ZergRush you, likely [[CurbStompBattle dropping you in seconds]] unless you can teleport out. On top of that, even if you do manage to kill one, it will start spinning around wildly [[LastDitchMove in a final effort to try and kill you]], causing rapid melee damage as it dies; thankfully, the Deflect Melee curse with the Devotion ability blocks all of the damage, if only for ten seconds.

[[folder:Examples from ''[=RuneScape=] 3'']]
* A literal example are the infamous Shadow Spiders. They aren't particularly damaging, but the minute one attacks you, it cuts your prayer points in half. When you consider that prayer points are used both to NoSell enemy attacks and give hefty buffs, you see why they're so dangerous, especially considering that Jagex loves to put these guys right at the start of several dungeons. It's even worse as of the Evolution of Combat, where not only are their homes multi-combat, but they now use ''ranged'' attacks.

* Lava strykewyrms are considerably harder than any of the other three types of strykewyrm, and have much more difficult mechanics to deal with, such as dragging you towards them. Like revenants, these monsters are also exclusive to the Wilderness, [[ParanoiaFuel putting you at constant risk of PKers attacking.]] On top of that, there is also a [[EliteMook stronger version]], the [=WildyWyrm=], that can appear at complete random, but hits much higher and has ''a million'' life points. Killing them, especially the [=WildyWyrm=], is a very risky gamble no matter what your approach - if you use cheap gear, you will struggle just to get one kill, but if you wear stronger gear, you become a tempting target for [=PKers=]. It's also not helped by the fact that they're one of the 151 monsters listed in the [[MonsterCompendium Slayer Codex]], if you intend to complete it as a requirement to trim the Completionist Cape.
* Dungeoneering:
** To lower levels, Dungeon Spiders, especially before the introduction of the Evolution of Combat. They can poison you, which does 50 damage every 20 seconds or so, which fades away very very slowly. Within Daemonheim, every resource is limited, including food, so losing this much HP is a major issue. However, it's not just that. They can poison you through prayers, which you would expect to stop that sort of madness[[note]]though to be fair, ''all'' poisonous monsters are capable of doing so[[/note]]. Fortunately, poison mechanics have changed since the launch of the Evolution of Combat[[note]]Poison now wears off after three minutes and does less damage per hit, though it does damage faster[[/note]], and even if you do get poisoned, there is a cure which can be bought for just 200 gp, and potions which give immunity for several minutes can be made with Herblore. In addition, they do not appear on Warped floors, but given how dangerous those floors are to begin with...
** Brutes. These [[MightyGlacier slow but tough]] foes are not as infuriating as the dungeon spiders and only appear on Furnished and Warped floors, but their attacks are utterly devastating, especially at higher levels where they will consistently hit into the 1000s. On furnished floors, they also feature in a puzzle room where you have to pickpocket them while they're asleep to obtain the key to the door. Failing to pickpocket them or making noise by running in the room and stepping on debris will result in you facing ''four'' of them at once.
** Dragons. Though rarer than brutes, they tend to hit harder thanks to their dragonbreath, which will hit you very hard if you do not have a [[LuckilyMyShieldWillProtectMe special shield]]. Worse yet, you might not even find said shield on the floor, and even if you do, it's worthless if your main weapon is two-handed, forcing you to waste time making a new weapon from scratch. Thankfully, Protect From Magic can be used to partially mitigate their breath, but even then it will still hit plenty hard.
** Forgotten Mages. Trying to get past all of those enemies in that one room with your Shadow Silk Hood? Good luck trying to pull it off without the hood's effects as they will promptly reveal you to the other monsters, who will proceed to ZergRush you. It certainly doesn't help that they can bind you in place and lower your melee stats, making it frustrating to kill them with melee. Necromancers are similar, except instead of trying to bind you, they instead summon zombies to attack with melee.
** Reborn Mages on Warped floors. In addition to being able to drain your stats and remove your Shadow Silk Hood's effects (if you have one) like Forgotten Mages, they can also summon hard-hitting Reborn Warriors that attack with melee. As if this wasn't enough, both Reborn Mages and Reborn Warriors can even ''follow you into other rooms''.
** One of the challenge rooms is a bit of a DemonicSpider ''web''. Imagine a Forgotten Mage, but with much higher stats ''and'' the ability to call in reinforcements to back him up, and you've got the Mercenary Leader. The number of reinforcements he calls in depends on how many people are on your team. On a solo dungeon he only calls three units. In a five-man group, he calls in ''fifteen'' units. Expect to be dropped in seconds in a group dungeon if you go in alone. Even in a solo dungeon, you can usually expect to use up a considerable amount of food or even take a death or two fighting him and three other mercenaries at once. On a members world, it might involve getting attacked from all three sides of the combat triangle at once by mercenaries in level 99 equipment, particularly if you're in Hard Mode. Thankfully it is fairly rare, and has been made considerably easier as of the Evolution of Combat.

* Goraks, extradimensional monsters that can ignore prayer, hit excessively hard, and drain your stats. They're only found in a couple places (God Wars Dungeon and the Gorak Plane), but they're extremely aggressive and can be dangerous if you don't have a quick means of escape or a way to raise your stats back up. Just to add to that, their drops mostly consist of low-level weapons and pitiful amounts of gold, with their only worthwhile drop being a hard clue scroll.

** The giant swamp snakes. Not only do they have powerful, fast melee and magic attacks, pack hefty HP, and come in packs, but unlike the other nasty monsters (shades, snails, ghasts, and nail beasts), they can't be easily distracted from your companion. When you enter the area for the event, you're almost guaranteed to get swarmed, with several of them focusing on your companion. If you don't have enough food in your companion, or are not quick to distract them with the Provoke ability, then you're screwed, and it can be outright impossible on the hard route without using Provoke.

* Pretty much ''[[EverythingTryingToKillYou everything]]'' on Ape Atoll, unless you're a monkey. The spiders and scorpions, despite being tiny, can hit pretty hard and inflict a nasty poison on you, and they'll respawn almost instantly after death. Ninja monkeys come in packs and can deal ungodly amounts of both melee and ranged damage, and the gorilla guards block your path, pack a mean punch, and can heal themselves, making them hard to kill. Even the slightly-less powerful zombie and skeletal varieties in the gnome tunnel will mob you if you give them the chance.
* The Temple Trekking swamp snakes are much more dangerous in ''Old School'' than they are in ''[=RuneScape=] 3''. While they only use melee here, they attack faster and hit harder than they do in ''[=RS3=]''. But the worst part is that once they start attacking your follower, there's no distracting them unlike in ''[=RS3=]''. If you don't kill them quickly, especially on the hard route, your follower won't stand a chance against their heavy damage output.

* Just about everything in Waterbirth Island counts, but special mention goes to the Rock Lobsters near the end just before the Dagannoth Kings. Their melee attacks are alarmingly fast and pack a fair punch, and they are highly resistant to everything except magic. Of course, they live in a multiway combat zone, so they'll quickly gang up on you, all but necessitating Protect from Melee if you want to survive. Oh, and there are also ranged-using Dagannoths and magic-using Wallasalkis nearby as well, so you'll probably end up taking heavy damage anyway and wasting your supplies that you'd otherwise be saving for the Dagannoth Kings.

* The tribesmen on Karamja. Though not very strong by any means, if they damage you, you'll be smacked with a pretty nasty poison that can deal 11 damage per hit - a lot of damage for ''Old School [=RuneScape=]'', and nearly three times what their actual attacks can hit. Thankfully, there is a shop that sells antipoisons if you get hit with it, and they stop bothering you once you reach level 65 combat, though they can still attack at random during the Tai Bwo Wannai cleanup minigame.

* Waterfiends. It's bad enough that they have accurate, hard-hitting ranged and magic attacks, but what makes them frustrating to kill is their obscene defence against anything that isn't a crushing attack. Most good melee weapons on ''Old School'' tend to be stab or slash weapons. Decent crush weapons are few and far in between, and the best ones cost quite a lot, while still being worse than similarly-levelled weapons like the Dragon Scimitar and Abyssal Whip. Not helped at all by their average-at-best drop table, inconvenient locations, and the fact that they are a very common assignment from high-level Slayer masters.
* Sourhogs, an obscure Slayer monster assigned by the lowest-levelled Slayer masters, Turael and Spria. They take more abuse and deal more damage than most of the other possible assignments from Turael and Spria, and require a special pair of goggles or a Slayer Helmet to kill. Forget either of those, and their max hit quintuples from 6 damage to ''30'' damage. The only saving grace is that they're locked behind a quest that isn't a part of any major storyline, and even then, they're assigned in small enough amounts that a task can go by fairly quickly.

** Iorwerth and Cadarn elves in Prifddinas. Unlike most ability-using monsters, their adrenaline meter is constantly locked at 50%, enabling them to use threshold abilities [[TheComputerIsACheatingBastard without having to build it up]]. It's not terribly uncommon to attack a Cadarn Magus and have him immediately stunlock you with an Asphyxiate combo. Worse yet, while the elves are not aggressive, it's not horribly uncommon for high level players with access to Morvran (the game's second highest-levelled Slayer master) to teleport to him while still under the effects of their aggression potions from a prior task, and immediately get [[ZergRush piled]] ([[CurbStompBattle and likely murdered]]) in the process of trying to get a new task. At least there are several banks and even a prayer altar within walking distance.

* Just about everything in Waterbirth Island counts, but special mention goes to the Rock Lobsters near the end just before the Dagannoth Kings. Their melee attacks are alarmingly fast and pack a fair punch, and they are highly resistant to everything except magic. Of course, they live in a multiway combat zone, so they'll quickly gang up on you, all but necessitating Protect from Melee if you want to survive. Oh, and there are also ranged-using Dagannoths and magic-using Wallasalkis nearby as well, so you're going to take heavy amounts of damage regardless if you're on your way to face the Dagannoth Kings.

* Cave crawlers, for similar reasons as the aforementioned Tribesmen. Although they're not aggressive, and their poison isn't as dangerous as the tribesmen's poison (though it can still hit 8s), what makes them DemonicSpiders is the fact that they are a Slayer monster, which means that you may sometimes be ''required'' to kill them. Worse yet, you can receive these from even the lowest level Slayer master at as low as level 10 Slayer and ''10 combat'' - that is, at a point where the poison will likely drop you in two hits. If your combat level is under 20 and you get them as a task, well, you'd better hope you brought some antipoisons. Fortunately, there are safespots in most of their locations where you can range or mage them.

* Pretty much ''[[EverythingTryingToKillYou everything]]'' on Ape Atoll, unless you're a monkey. The spiders and scorpions, despite being tiny, can easily smack you with nasty poison and respawn almost instantly after death. The monkeys come in packs and can deal ungodly damage, and the zombie and skeletal varieties in the gnome tunnel will mob you if you give them the chance.

* How about a few from the SpinOff, ''Old School [=RuneScape=]''?[[note]]Most of these wouldn't count in ''[=RuneScape 3=]'' due to being either non-aggressive or much weaker there.[[/note]]
** The infamous Dark Wizards south of Varrock, the ultimate bane to new players' existence. Aggressive monsters with surprisingly strong magic attacks, they can kill any player fresh off Tutorial Island in as few as two hits. Newcomers might head up to Varrock for the first time, only to be picked off by the wizards on the way there and lose their tutorial gear. Making matters worse, their combat level is [[MinMaxing deceptively low for the damage they deal]], and they are even capable of giving higher-levelled players a run for their money.
** Not as deadly as the dark wizards, but still a fair threat, are the Draynor jail guards. Even though they only hit half as hard as the aforementioned dark wizards, it's still enough to drop a new player in four hits. Compounding matters further, they are aggressive and located in a multicombat area less than a minute away from Lumbridge, the starting town. To new players just starting out, they can be a nightmare to deal with, but at higher levels, they decrease to GoddamnedBats status. In fact, medium-level players may even exploit their aggression and use them for training, particularly in free-to-play.
** The tribesmen on Karamja. Though not very strong by any means, if they damage you, you'll be smacked with a pretty nasty poison that can deal 11 damage per hit - a lot of damage for ''Old School [=RuneScape=]'', and nearly three times what their actual attacks can hit. Thankfully, there is a shop that sells antipoisons if you get hit with it, and they stop bothering you once you reach level 65 combat, though they can still attack at random during the Tai Bwo Wannai cleanup minigame.
** Cave crawlers, for similar reasons as the aforementioned Tribesmen. Although they're not aggressive, and their poison isn't as dangerous as the tribesmen's poison (though it can still hit 8s), what makes them DemonicSpiders is the fact that they are a Slayer monster, which means that you may sometimes be ''required'' to kill them. Worse yet, you can receive these from even the lowest level Slayer master at as low as level 10 Slayer and ''10 combat'' - that is, at a point where the poison will likely drop you in two hits. If your combat level is under 20 and you get them as a task, well, you'd better hope you brought some antipoisons. Fortunately, there are safespots in most of their locations where you can range or mage them.
** Pretty much ''[[EverythingTryingToKillYou everything]]'' on Ape Atoll, unless you're a monkey. The spiders and scorpions, despite being tiny, can easily smack you with nasty poison and respawn almost instantly after death. The monkeys come in packs and can deal ungodly damage, and the zombie and skeletal varieties in the gnome tunnel will mob you if you give them the chance.
** The Temple Trekking swamp snakes are much more dangerous in ''Old School'' than they are in ''[=RuneScape=] 3''. While they only use melee here, they attack faster and hit harder than they do in ''[=RS3=]''. But the worst part is that once they start attacking your follower, there's no distracting them unlike in ''[=RS3=]''. If you don't kill them quickly, especially on the hard route, your follower won't stand a chance against their heavy damage output.
** Waterfiends. It's bad enough that they have accurate, hard-hitting ranged and magic attacks, but what makes them frustrating to kill is their obscene defence against anything that isn't a crushing attack. Most good melee weapons on ''Old School'' tend to be stab or slash weapons. Decent crush weapons are few and far in between, and the best ones cost quite a lot, while still being worse than similarly-levelled weapons like the Dragon Scimitar and Abyssal Whip. Not helped at all by their average-at-best drop table, inconvenient locations, and the fact that they are a very common assignment from high-level Slayer masters.

** The Temple Trekking swamp snakes are much more dangerous in ''Old School'' than they are in ''[=RuneScape=] 3''. Not only are their attacks faster, but once they start attacking your follower, there's no distracting them unlike in ''[=RS3=]''. If you don't kill them quickly, especially on the hard route, your follower won't stand a chance against their heavy damage output.

* Revenants, powerful Wilderness-dwelling ghosts that can attack from all three corners of the combat triangle. They will ZergRush you as soon as you enter their lair, the Forinthry Dungeon (in ''3'') or the Revenant Caves (in ''Old School''), which can be deadly considering they can hit almost as hard as (and in some cases harder than) players of similar combat level (though in ''3'' there is an item you can use to make them non-aggressive, and ''Old School'' has a similar item that dramatically reduces their damage output). They also have the ability to rapidly heal themselves when their health drops low, so you'll probably spend more time killing them than you would want to. It certainly doesn't help that you can be attacked by [[PlayerKilling PKers]] at any time, and given how valuable some of their drops are, [[ParanoiaFuel you're very likely to encounter a PKing team there at some point]]. They were worse when they were originally introduced into the Wilderness as a replacement for [=PKers=] following the infamous 12-10-07 update to remove [[PlayerVersusPlayer PvP]] in the Wilderness. Not only did they roam all around the Wilderness, but they could teleblock and bind you in addition to their healing powers and high damage output, not to mention that if you could succesfully kill them, their drops were much worse than what they currently are (their original best drop was a measly ''dragon scimitar''). Thankfully, when PlayerKilling returned about three years later, they were contained in the aforementioned Forinthry Dungeon, and also lost their bind and teleblock powers.