Monsters in Dungeons & Dragons take a wide variety of forms ranging from oozes like Black Puddings to aberrations like Beholders. Of the various types of monsters that appear in D&D, one of the most dangerous categories of foes is fiends. The vast majority of fiends are either a form of demon or devil, originating from D&D's Nine Hells and/or the Abyss.
As many of the most deadly foes in D&D tend to be arch-fiends, few other types of foes are home to as many high CR monsters as fiends. So today, we're going to examine the most fearsome fiends in D&D's fifth edition.
Updated on April 10, 2022, by Paul DiSalvo: Alongside Dragons, fiends are among the most powerful types of monsters that adventurers can encounter in Dungeons & Dragons. For those looking for a collection of the strongest monsters the game has to offer, Monsters of the Multiverse notably includes a wide variety of Arch Devils and Demon Lords, the most powerful named fiends within the lore of D&D. Or for those looking for antagonists perfect for a high-leveled D&D party, many of these fiends are the most dangerous adversaries D&D's fifth edition has to offer.
13 Juiblex
Known as the "Faceless Lord," Juiblex is the Demon Lord of slime and ooze, serving as the progenitor of all ooze within the multiverse. While a massive ooze-like being in its own right, Juiblex is in fact classified as a fiend. Capable of regenerating hit points each turn, Juiblex is capable of dealing absurd amounts of acid damage to its adversaries through the combination of its Acid Lash and Eject Slime attacks.
As Juiblex is capable of worsening the effectiveness of someone's gear through the use of corrosive slime, when paired with its regenerative HP, a party must aim to defeat this fiend quickly before the encounter gets out of hand if they hope to emerge victoriously.
12 Zuggtmoy
Zuggtmoy is among the most alien and detached Demon Lords of the Abyss, serving as the Lady of Rot and Decay. While Zuggtmoy may not be able to deal as much immediate damage as other fiends on this list, she should not be taken lightly under any condition.
Through the use of spores, Zuggtmoy is capable of not just mind-controlling others, but she can inflict creatures with a deadly disease known as the "Spores of Zuggtmoy," which can slowly cause a creature to be overtaken by fungal growth, being turned into a Myconid. In addition to the horrors that come with the spore-based capabilities of the Demon Lord, she can notably cast the spells Etherealness and Teleport.
11 Yeenoghu
Yeenoghu is a terrifying and deadly Demon Lord that can be found within its lair in the Abyss known as the Death Dells. The progenitor of Gnolls, this brutal and carnivorous fiend is rabid and aggressive, seeking to wreak as much havoc as possible. With a massive pool of hit points, Yeenoghus is capable of dealing severe damage through the use of its flail and bite attacks.
While its damage output is quite potent, Yeenoghu's flail can notably inflict its targets with various hindering ailments, whilst Yeenoghu itself is capable of casting high impact spells like Dispel Magic, Invisibility, and Teleport. If fought within its lair, Yeenoghu grows all the more dangerous, gaining the ability to assist gnolls in combat as well as restrain its foes through the use of piercing iron spikes.
10 Rakdos
While Rakdos is a character with origins within Magic: The Gathering, thanks to the Guildmaster’s Guide to Ravnica, Rakdos is one of the most powerful fiends in D&D. WIth a CR of 24 and a massive pool of 300 HP, Rakdos has access to a terrifying blend of damage and status effects.
Simply being near Rakdos is playing with fire, as whenever a creature gets within 30 feet of the demon, they must make a DC25 Wisdom saving throw or become charmed for a minute.
9 Graz'zt
Another of the most powerful demons in D&D, Graz’zt is one of the Demon Lords of the Abyss, serving as the lord of debauchery and hedonism. With a plethora of notable resistances and immunities and 346 HP, Graz’zt is quite flexible and unpredictable in combat.
Innately capable of teleporting, Graz’zt has access to several potent spells such as Greater Invisibility and Dominate Monster. As if this weren’t scary enough, Graz’zt is also capable of dishing out serious melee damage with his greatsword, the Wave of Sorrow. Graz'zt can be a headache for even the most experienced of parties, as its capable of countering spells and possesses various means of charming others.
8 Kostchtchie
A Demon Lord that serves as the patron of the frost giants, Kostchtchie is a fiend that is as resilient as it is deadly. With both magic resistance and access to legendary resistances, it can be quite difficult to deal meaningful damage to Kostchtchie.
One of the most threatening aspects of Kostchtchie is his access to massive damage potential thanks to his Warhammer, Matalotok paired with his ability to curse a foe, giving them temporary vulnerability to all damage.
7 Bel
The first archdevil on our list, Bel is a fiend with an absolutely devastating damage output. Capable of innately casting fireball at will and as a legendary action, also having access to the likes of Meteor Swarm and Imprisonment.
As if this weren’t deadly enough, getting close to Bel forces a character to make a DC 23 Wisdom save, becoming frightened on a failed save.
6 Demogorgon
Demogorgon is one of the most deadly Demon Lords of the Abyss, boasting a CR of 26 and 464 HP. As you would expect from a Demon Lord, the Demogorgon is a fearsome fiend with a plethora of deadly tools at its disposal including spells like Feeblemind and Dispell Magic.
Outside of its magic and its devastating tentacles that can reduce a target's maximum HP, one of its most dangerous tools is its gaze, capable of charming, stunning, or inflicting a target with the confusion spell.
5 Orcus
Another fiend with a CR of 26, Orcus is the chaotic evil Demon Prince of the undead. While Orcus is a powerful foe in its own right, capable of dealing serious damage and even casting Time Stop, the most notable aspect of Orcus is his signature weapon, the Wand of Orcus.
With this wand, Orcus is capable of instantly summoning any amount of undead creatures under its control as long as their combined HP doesn’t exceed 500. This means that when fighting Orcus, not only does a party need to deal with a potent demon lord, but an army of the undead as well.
4 Zariel
A former angel, Zariel is a being that underwent a transformation to become the archdevil lord of Avernus, dedicating herself to winning the blood war between demons and devils. As a war-focused archdevil, it should be no surprise that Zariel is one of the most dangerous fiends in D&D. With 420 HP, Zariel is incredibly difficult to put down, regaining 20 HP every turn as long as she hasn't been dealt radiant damage that turn.
This is far from convenient, as Zariel is resistant to radiant damage, meaning that in order to prevent her from regaining her health, you must sacrifice your damage output. Zariel also boasts terrifying damage potential, capable of innately casting Fireball and Wall of Fire at will, while she can deal up to 30d8 worth of damage through the use of her flail or longsword.
3 Rak Tulkhesh
Rak Tulkhesh is an immensely potent fiend of Ebberon, serving as the Avatar of impure drives to violence, aiming to spread as much bloodshed as possible. Few D&D monsters have access to as many devastating melee potential as Rak Tulkhesh, tripling damage dice on criticals while having access to Banishing Smite, Blinding Smite, and Staggering Smite.
As if this weren’t bad enough, simply being within ten feet of Rak Tulkhesh causes a creature to take 4d6 force damage due to the whirlwind of weapons that surround the fiend.
2 Sul Khatesh
Like Rak Tulkhesh, Sulk Khatesh is a fiend hailing from Eberron. A manifestation of fears and superstitions, Sul Khatesh is a devastating magical threat with access to a myriad of incredible spells such as Gate, Teleport, Power Word Kill, Mass Suggestion, and Chain Lightning.
Sul Khatesh is even capable of prematurely ending another creature’s concentration spell to gain HP or even creating Arcane Cataclysms that deal 11d12 force damage and have an excessive range of up to one mile.
1 Tiamat
The god of chromatic dragons, Tiamat is easily one of the most dangerous beings that players can go up against in D&D. With a CR of 30 and over 600 HP, not only is Tiamat resilient, but it's capable of dealing devastating amounts of damage through its access to five separate breath attacks.
Tiamat’s defenses are quite noteworthy as well, completely negating damage spells of sixth level or lower.