While thoughts of the fey might first drive one to imagery of faeries, pixies, and dryads, the Feywilds of Dungeons and Dragons are also home to creatures of a more malicious nature. The fey encompasses any creature who is derived from the Feywild, a magical plane parallel to the Prime Material Plane. Whether transformed by the magic of the Feywilds or originally born inside of them, fey creatures all exhibit innate magical abilities.
Furthermore, most fey have a connection to nature, but many of the most dangerous kinds of fey have perverted that connection. What was beautiful has become ugly, what birthed life instead squelches it, and what reinforced the cyclical nature of life now seeks to destroy it.
Updated August 10, 2021 by Noah Smith: Dungeons & Dragons is a long-running game, full of content from across the decades. Two additional fey creatures were from 3rd Edition were added at the end. These evil creatures are designed to be mid to end of campaign foes as their challenge ratings are 11 and 16 respectively.
12 Darkling Elder
All darklings come from a lineage of fey cursed by the Summer Queen. The curse doomed their bodies to absorb sunlight and result in expeditious aging. The oldest and most capable of darklings might subject themselves to a ritual that, through the use of body tattoos, transforms them into a darkling elder.
Elders resemble elves and are similarly dexterous. They make use of shortswords to attack and have innate access to the darkness spell. When they are killed, elders' bodies explode in a radiant flash of light. Creatures within ten feet must make a DC 11 Constitution save or take 2d6 radiant damage and be blinded until the end of their next turn.
11 Meenlock
Meenlocks are the result of fey creatures that experience an overwhelming amount of fear and terror. Such a creature is deformed, as their body manifests into an amalgamation of their own fears. These creatures of the dark seek only to corrupt that which is good, primarily by creating more meenlocks through the capture and torture of other humanoids.
Instead of hands, meenlocks possess wicked, sharp claws capable of paralyzing potential prey. Any creature that gets too close to one has a chance of being frightened by their fear aura. On top of all that, meenlocks can teleport up to 30 feet as a bonus action as long as the areas in which the teleportation takes place are shrouded in darkness.
10 Sea Hag
All hags are a perversion of all that is good in the Feywild, and are rebuked by the rest of the realm's denizens. Sea hags in particular are a distortion of the realm's beauty as they are ugly, wretched things (even by hag standards). If a sea hag even lays her eyes upon something beautiful, it draws her into a fit of rage as she schemes to destroy or corrupt it. The sea hag's terrible appearance inspires fear in those who come near her, requiring a DC 11 wisdom saving throw or frightening a creature within 30 feet.
Sea hags are capable of disguising themselves as everyday folk, though even these illusory forms are quite ugly. Other than her savage claws, a sea hag attacks with her most potent ability: death glare. She targets one frightened creature within 30 feet, forcing them to make a DC 11 wisdom saving throw. On a failure, the target drops to 0 hit points. In this case, looks really can kill.
9 Green Hag
Green hags are a bit more powerful than sea hags, though not quite as deadly. Instead of the death gaze ability, green hags have invisible passage. This ability allows the green hag to magically turn invisible until she makes an attack or casts a spell. It's impossible to track a green hag using invisible passage unless through magical means, so the ability ultimately makes for the perfect escape mechanism.
Most notably, green hags can cast minor illusion and have a mimicry ability that allows them to mimic animal and humanoid sounds.
8 Redcap
Redcaps are murderous little buggers that delight in slicing others into messy bits. It's a good thing they enjoy it, because any redcap who doesn't kill something or someone within 3 days magically poofs out of existence.
These hunchbacked gnomes are called redcaps as a result of their habit of dipping their pointy hats in the blood of their victims. Despite their small stature, redcaps aren't interested in sneaking up on anyone. Instead, they wear heavy iron boots that make a ruckus. Redcaps use their iron-toed shoes to charge enemies and lay them low. Then, they proceed to chop opponents up with their sickles.
7 Yeth Hound
A yeth hound is a big, burly dog with a face resembling that of a human, besides its glowing red eyes. Yeth hounds are ferocious hunters when alone or as part of a larger pack, but their true wish is to find an evil master to serve. After all, bad guys need a best friend too. Yeth hounds are resistant to nonmagical attacks made with nonsilvered weapons and can form a telepathic bond with their master.
The most dangerous feature of a yeth hound is its baleful baying, which causes all creatures within 300 feet to make a DC 13 wisdom saving throw or become frightened. While frightened, the creature must run from the yeth hound and takes extra psychic damage from its attacks. Yeth hounds do have one easily exploitable weakness though: sunlight. A yeth hound exposed to sunlight is immediately transported to the ethereal plane.
6 Annis Hag
Annis hags are the most physically powerful of their kind and are rightly feared by their dark sorority sisters. Defying the stereotype of the withered crone, Annis hags stand over 7 feet tall and are composed of burgeoning muscles. Altogether, they resemble a deformed ogre more so than any of their own kind. Annis hags are known for crushing any resistance that meets them with an embrace of monumental strength.
A creature swept up into the annis' arms takes 9d6+5 bludgeoning damage immediately, and takes the damage again at the beginning of each of the hag's turns. A character can escape this deadly hold with a DC 15 strength check. Safe to say, these grandmas give hugs a bad name.
5 Korred
Unlike most of the creatures on this list, Korreds aren't inherently evil. They're just a bit chaotic. Korreds are small fey with the legs of a goat and hair so long and bushy that it obscures everything but their legs and face. A korred takes great pride in its mane, likely in part because the hair itself is magical. While mostly reclusive creatures, korred enjoy boisterous celebrations with their fey friends where they dance until dawn.
Interrupting such a celebration is seen as a great offense though. Depending on the korred, it might even be cause for violence. An angry korred is a dangerous foe, as its attacks are strengthened while it touches the ground, and its hair can be used to entangle enemies as a bonus action. Korred can also cast conjure elemental as well as Otto's irresistible dance.
4 Bheur Hag
Also known as winter hags, bheur hags are cold to their core. They delight in bringing misery to others through the manipulation of the weather, particularly weather that's bitingly cold. Bheur hags love to watch others turn to selfishness and insanity in an attempt to survive the struggles of winter. They wield spells including hold person, cone of cold, wall of ice, and control weather of their own accord.
Furthermore, these hags make use of a magical item called a graystaff which they can ride like a broom of flying. However, the staff also serves as her spellcasting focus. If an adventurer is fortunate enough to deprive a bheur hag of her graystaff, she loses her ability to cast all of the aforementioned spells.
3 Autumn / Spring / Winter / Summer Eladrin
Unlike other elves, eladrin are fey who are ruled by their emotions. So much so that terrible bouts of these emotions cause them to physically change into a seasonal form befitting their feelings. Autumn for goodwill, spring for joy, summer for anger, and winter for sorrow.
Each form possesses its own unique spells and abilities, but every form can fey step as a bonus action (which is basically the spell misty step). Eladrin love beauty in all its forms. Evil ones will try to steal beauty away for themselves while good ones will attempt to share it for all to see.
2 Verdant Prince
Cruel and manipulative, Verdant Princes are the evil monarchs in the Feywilds. They love to make bargains with needy adventurers that wander into their domain and hide their cruel nature under a kind facade. Always male, Verdant Princes have incredible magical abilities and would pose a threat even to the most cautious of parties.
What's more, they possess an innate ability to take revenge on people who broke their bargains. Verdant Princes can make an Oath Bond, a magical and binding bargain with those in need. If either party breaks this bond, the betrayed will immediately know the distance and direction of the wrongdoer, who will immediately become sick.
1 Frostwind Virago
The petite and viciously cold, Frostwind Virago are probably one of the most dangerous fey a party could encounter. So cold that even fire does not harm them, Frostwind Virago have a knack for tricking travelers into their lair with their ability to charm people at will.
Furthermore, they can emit an aura around them that can daze and stun upon getting close, and summon great whirlwinds filled with shards of ice. A menacing foe, these creatures live in cold and remote climates. Some may establish themselves as rulers over a frozen area, while others tend to live solitary lives.