Nightmares are a monstrous species of equines that originated from Dungeons & Dragons. Like so many other D&D beasties, they owe their existence to the inherent playfulness of Gary Gygax and his buddies; in mythology, "Mara", or a "Night Mara", is an evil spirit in the form of a hag or goblin that likes to torment people by sitting on their chests in the middle of the night and filling their dreams with fearful imagery. This is where we get the term "nightmare" from. D&D decided to go for a pun-based interpretation, and created a race of fiendish horses native to the Lower Planes, characterized by their jet-black hides, burning manes, and famous for their ability to breathe fire, their supernatural speed, and their ability to travel between planes at will.
The image was so striking that nightmares of this sort have become adopted into fantasy consciousness, and few people are aware of the fact they were originally a silly joke (Though if you wanted to make a "demonic horse", making it black with a mane of fire is probably the easiest way and not very creative, so it's just as likely these copycats came up with the design themselves).
Nightmares have had a long history in D&D, so sit back and get ready to enjoy the ride.
AD&D 1st Edition
The nightmare debuted in the Advanced Dungeons & Dragons 1st edition Monster Manual, which describes it as a gaunt and skeletal hell horse with an oversized head, a jet black coat, and a wild and rugged mane. It has red eyes, and nostrils from which orange flames protrude. Its hooves burn like embers, and sharp fangs protrude from its mouth. Although it doesn't specify which plane they originate from, the Monster Manual notes that nightmares are lower planar creatures often used as mounts by other evil denizens. Unsurprisingly, this has given them the alternative names of "demon horses" and "hell horses". Part of the appeal of such a mount to its rider is likely the nightmare's ability to fly and travel into the ethereal and astral planes.
Even without a rider, a nightmare is a dangerous foe. They are ill-disposed to most forms of life, and will attack without provocation. As well as a bite attack (2-8 damage), and burning hooves (two attacks, each doing 4-10 damage), the nightmare is also able to breathe out a cloud of hot smoke which causes a -2 penalty to attacks and damage if the saving throw is unsuccessful. It has an extremely good armor class (-4), high speed (15" or 36" in flight) and 6+6 hit dice.
Dragon #50 notes that nightmares are carnivorous, and that they particularly enjoy the meat of some lesser demons and devils (particularly manes and lemures). Failing to feed a nightmare its preferred diet may make it hostile to its owner. According to the article Arrrgh!!! in Dragon #118, nightmares have a high pain threshold, being more resilient than griffons, hippogriffs and perytons and similar to wyverns. The 1st Edition Player's Handbook notes that nightmares are not susceptible to invisibility to animals because of their high intelligence.
Nightmares have low-key appearances in a number of 1st Edition adventures, including the drow series (D1-D3). The device of the drow House of Noquar is a bronze nightmare's head and the drow of Erelhei-Cinlu, particularly nobles, keep nightmares as steeds. The affinity of drow for these exotic mounts extends right up to Lolth herself. The Stable of the Nightmare in level two of Q1: Queen of the Demonweb Pits houses Lolth's personal steed, cared for by two manes. Her nightmare is wearing horseshoes of a zephyr, which, given that these allow a steed to travel without touching the ground, seems a little redundant for a flying mount.
Inside one of the burial mounds of Dolem Moor in C5: The Bane of Llywelyn is a lone nightmare, and similarly, the article Grave Encounters in Dragon #114 lists nightmares as potential encounters in evil-enchanted graveyards. In C6: The Official RPGA Tournament Handbook, the nightmare residing in Keep Anelle is an aggressive individual. It viciously attacks any intruders, except, apparently, the hellcat living nearby.
A slightly more unusual nightmare can be found in Dragon #42. The characters in the adventure The Mansion of Mad Professor Ludlow are children on a camping trip. While exploring the mansion, they may come across a motionless nightmare which only reacts if mounted by a character carrying something magical. If that happens, the nightmare animates, and returns back to hell, taking its rider with it.
AD&D had more than one evil version of the paladin, and the nightmare is an obvious choice of potential steed for such a class. The Anti-Paladin NPC in Dragon #39 suggests a 25% chance of an anti-paladin's special warhorse being a nightmare. The arrikan, a neutral-evil paladin variant detailed in A Plethora of Paladins in Dragon #57, also has a chance to call a nightmare as a steed, but this is only 5%, and only a single replacement steed can ever be called if the first one perishes.
For those considering the potential of nightmares as transportation, the article The Ups and Downs of Riding High in Dragon #50 looks at the suitability of the flying creatures in the Monster Manual as steeds. Nightmares are deemed to be suitable primarily for undead riders. The section on a nightmare's carrying capacity is confusing. It declares that the "semi-material" nature of the nightmare means that it can carry only undead on its back, but if it has a rider and is travelling to the ethereal plane, it can carry "up to 6,000 gp of additional weight" for some reason.
The planar nature of the nightmare is explored only peripherally in AD&D. In Deities & Demigods, the nightmare is included on the encounter tables for both the astral and ethereal planes. It is also noted that nightmares are commonly associated with the god Hades. In The Inner Planes in Dragon #42, the nightmare is a rare encounter in the elemental planes of Earth, Water and Fire, as well as being attracted by "warps" into the negative plane.
The Monster Manual II lists the nightmare as a very rare encounter for a typical abyssal layer. It is also very rarely encountered on the 1st, 8th and 9th layers of Hell, but merely rare on layers 2-7. Finally, the Manual of the Planes clarifies that nightmares can be found on the planes of Tarterus, Hades, and Gehenna. The encounter tables in the Manual of the Planes again confirm that nightmares are visitors to the ethereal plane (alone or in pairs), as well as the astral (in groups of up to four).
AD&D 2nd Edition
There were some notable omissions from the first few volumes of the 2nd Edition Monstrous Compendium. As an (over-)reaction to some of the negative publicity the game had received during the 1980s, TSR decided not to include demons and devils in 2nd Edition. Predictably, all this did was annoy D&D fans, so two years into the release cycle, the lower planar denizens were restored, albeit with the offensive names "demons" and "devils" filed off and replaced with "tanar'ri" and "baatezu". Several other creatures, including the nightmare, were incidental casualties of this policy, and also had to wait until MC8: Monstrous Compendium Outer Planes Appendix was released to see print.
Technically, the nightmare did appear in one 2nd Edition adventure before then. In A Rose for Talakara in Dungeon #25, the villain keeps a nightmare named Blackspike. Despite being a 2nd Edition adventure, the reference given for the nightmare is the 1st Edition Monster Manual. Curiously, the XP value for the nightmare differs from the 1st Edition Dungeon Masters Guide but is consistent with what would eventually appear in the Monstrous Compendium. An entry for morale -- a stat new to 2nd Edition -- is also included, but it is listed as "special" instead of the "elite (13-14)" value which eventually appeared in the Monstrous Compendium entry.
Other than the new XP value and the addition of morale and diet (carnivore), the statistics for the nightmare in the Monstrous Compendium Outer Planes Appendix are unchanged from those in the Monster Manual. The description, however, is greatly expanded, with the nightmare getting a full page to itself.
We get a little bit more about their combat abilities. Their burning hooves will set combustibles on fire, and their cloud of hot smoke has a range of 10 feet and requires a save vs. paralyzation to avoid the penalty. The fact that their flight is a magical ability is spelled out, and we learn that they can understand commands from "evil riders" (why only evil riders?) and that they use "empathy" to communicate with each other, which is regrettably vague.
In 2nd Edition, nightmares have a bit more personality than they did previously. Although they willingly serve as a mount for any mission involving evil, they now have ambitions of their own. Nightmares are compared to magical weapons with large egos -- you can never be entirely sure that they are going to do what you want them to do.
The Monstrous Compendium Outer Planes Appendix is the first time the Gloom Meet is mentioned. This is a gathering of lower planar denizens on the plane of Hades, and takes place one per decade. Nightmares play a key role in spreading the word that the time of Gloom Meet is approaching, and the likelihood of encountering one of the creatures is higher during this time. Once the Gloom Meet begins, the nightmares announce this with a terrifying charge through the planes.
The Monstrous Compendium entry notes that nightmares are unrelated to horses, despite their resemblance. It also clarifies their "carnivore" diet. Although they are in the habit of eating the flesh of fallen opponents, they require neither food nor air to survive. It is suggested that they gain their strength solely through their service to evil.
The 2nd Edition emphasis on nightmares with more personality continued in the Deck of Encounters, Set Two. One of the encounters in the set is with a nightmare who was summoned by an ambitious wizard's apprentice to slay his master. This did not turn out well for the apprentice, as it rebelled against his control and killed him. In another encounter in the same set, a nightmare has no qualms about abandoning her rider if the battle goes against him.
There isn't much additional lore on nightmares in other generic 2nd Edition products, although as we'll see below, they have a significant presence in some of the many campaign settings. We get a brief mention in the article The Demiplane of Shadow in Dragon #213, which includes nightmares on that plane's encounter list, and in the The Complete Book of Necromancers it is noted that a necromancer would need to be at least 18th-level to attract a nightmare as a familiar.
Finally, during the 2nd Edition era, TSR produced the Spellfire collectable card game. The nightmare featured on card #76 of the Birthright expansion, but the card simply recycled the artwork from the Monstrous Manual.
The most significant change to the nightmare in 3rd Edition is a visual one. Despite the written description making no mention of additional fire, the nightmare in the Monster Manual now has both a flaming mane and a flaming tail. It has also picked up weight, and is no longer skeletal in appearance. As we'll see, this depiction became the norm from this point forwards.
In terms of its description and statistics, the nightmare remains remarkably similar to its earlier edition cousins. It has slightly more hit points and does a bit more damage (now split into physical and fire damage), but it has the same special abilities: flaming hooves, defensive smoke, and the ability to travel into the astral and ethereal planes. The smoke attack is now cone-shaped but extends slightly further, to 15 feet. It gives the nightmare a measure of concealment against opponent, without impeding its vision. The astral and ethereal travel abilities are specified as being the same as the equivalent spells cast by a 20th-level sorcerer.
For the first time, there is a mention of nightmares "haunting the dreams" of those who have crossed them, but this appears to be poetic licence with the description, rather than a new ability. Although nightmare are still used as mounts by powerful evil creatures, they appear to be more reluctant to allow others to ride them than before. While mounted, they cannot fight independently unless their rider makes a successful ride check. Their carrying capacity is specified as being up to 900 pounds. The Arms and Equipment Guide lists them as "untrainable". Since Nightmares both fly by magic (instead of wings), are suitable as a mount and clearly have a skeleton (the outline of their ribs are visible in the art), they're a good target for killing and animating as skeleton mounts. This is helped by their low HD and Outsider status making them valid targets for Lesser Planar Binding, freeing a necromancer of the need to actually locate one to kill.
The "advancement" entry indicates that some nightmares can be huge in size, with up to 18 hit dice. When the nightmare was updated for the Monster Manual v.3.5, a huge version was given its own stat block as a "cauchemar" (French for "nightmare"). The 3.5 nightmare also gained darkvision 60 ft., and its environment was amended from "any land and underground" to specify the Gray Wastes of Hades as their home.
The line from the 2nd Edition monster statistics block indicating a creature's diet was not carried over to 3rd Edition, making it default to the Outsider standard of not needing to eat. In Dying of the Light (Dungeon issue #84) the vampire Lythia keeps two nightmares which she uses to draw her carriage and under the seat she keeps a leather sack filled with platinum filings to feed the pair.
The 3rd Edition Manual of the Planes maintains nightmares as possibles encounters in the astral and ethereal planes, as well as the Tarterian Depths of Carceri, the Gray Waste of Hades, the Nine Hells of Baator and the Abyss. No specific mention is made of their presence in Gehenna, but the encounter tables imply that they can still be found throughout the lower planes.
Just in case a player wants a nightmare PC, the article Monsters with Class in Dragon #293 suggests that the Effective Character Level (ECL) of such a character would be 10, meaning that it would be treated as ten levels higher than ordinary humanoid adventurers. This article was a preview of Savage Species but the nightmare didn't make it into that book, probably because it isn't a particularly playable race.
The Tome of Magic includes the fiendbinder class, which uses truenames to bind fiends and other creatures into service. The cauchemar nightmare is one of the creatures that can be bound by a fiendbinder of at least 5th level.
In Expedition to the Demonweb Pits, the adventurers visit the planar city of Zelatar. While there, there is a possibility that they can persuade a group of cauchemar nightmares to help them navigate the city. So bored are the nightmares with acting as mounts for dignitaries and merchants, that they will co-operate with the party as long as their intention is to leave Zelatar, and provided the heroes are reasonably competent riders.
In the 4th Edition preview book Wizards Presents: Worlds and Monsters, we get both a first mention, and a first glimpse of the nightmare. There is a black and white illustration in the Shadowfell section, and it is noted that the shadar-kai capture nightmares to use as mounts, implying that the steeds have been displaced from the lower planes to inhabit a new home. The depicted nightmare is both heavily armored and heavy. There is nothing remotely skeletal about this beast, and it has extensive ornate barding covering its legs, head and neck. This is likely magical barding because it appears to cling to the nightmare despite no visible straps or means of attachment.
The nightmare which appeared in the Monster Manual a few months later is not armored, but retains the well-defined muscular appearance. It is also the most flame-engulfed version we've seen so far, with fire now leaping out from the nightmare's head and torso. In death, these flames go out, and its mane and tail turn to ash.
Mechanically, this is a simpler beast. It can no longer shift between planes, but gets a short-range teleportation ability instead, although the text notes that some particularly powerful individuals are capable of travelling to the Shadowfell. The nightmare has lost its bite and smoke breathing capabilities, and is limited to attacking with hooves. The only special attack it has is to leave a trail of fire behind it when it charges. It is able to extend its own fire resistance to a rider of sufficient power (13th level).
Although it is still described as intelligent, its intelligence score has dropped to sub-human levels and it is incapable of communicating in any language. The nightmare seems to be back to a carnivorous diet, which could explain the dramatic weight-gain. Nightmares have a taste for human flesh.
In theory (although not always in practice) nightmares of earlier editions were solitary creatures. These Shadowfell-dwelling versions are very much herd animals, even attacking in wolf-like packs. They get their name from the terrifying dreams experienced by survivors of their attacks. Nightmares enjoy spreading fear and terror and are known to let their targets think they have escaped, before closing back in for a kill.
Although they are still used as mounts by powerful evil creatures, such riders must now first defeat a nightmare in combat, and give the beast a choice of service or death in order to compel it to serve as a mount. Despite this rather onerous requirement, the Adventurer's Vault includes the nightmare on a list of potential mounts for adventurers. With a price tag of a mere 25,000 gp, the nightmare compares favourably with a wyvern (21,000 gp) or a manticore (45,000 gp), and has a faster flying speed than either of them.
Open Grave offers a slightly more powerful nightmare, Maheghoda the Black Course, ridden by the death knight ruler of a city populated by undead. Although Maheghoda is a unique creature with improved hit points, AC and attacks, it does not have any new abilities.
The article Codex of Betrayal: Alloces in Dragon #373 mentions that the devil known as the Butcher of Nessus claims to have created the first nightmares. Although the same article also states that his claim is unlikely to be true, it acknowledges that Alloces has bred new, more potent nightmares. Quite how this lore dovetails with the nightmare's new home in the Shadowfell is unclear here, but a later article offers an explanation, as we'll see below.
The adventure E1: Death's Reach introduces creatures called shadowclaw nightmares, but contains frustratingly little in the way of description or explanation as to what these are. They can clearly be mounted, so could be horse-like in nature. They are also large shadow beasts, like the nightmare, but unlike the nightmare, they are undead and capable of reanimating once slain. Are they relatives of the nightmare? It is impossible to tell from Death's Reach.
A boxed set released towards the end of 4th Edition, The Shadowfell: Gloomwrought and Beyond, provides a little more detail of the shadar-kai relationship with nightmares. We learn that some shadar-kai have mastered a tactical manoeuvre where they leap from the backs of their nightmare steeds directly into combat. Svyn, the religious leader of the network of mountain caves known as Thyrin Gol, roams the Shadowfell on the back of a nightmare steed named Sear, searching out the mysteries of the plane. There are also rumours that a jet-black unicorn has seized the leadership of the herd of nightmares living in the nearby Gol Mountains.
According to Underdark, deep within the Shadowdark a pair of nightmares is chained to the body of a purple worm, which is used as a bridge over the River Lathan, also known as the River of Souls.
Strangely, it is the nightmare's last 4th Edition appearance that provides the most detailed version of the creature. Following on from the Essentials reboot, a number of monster update articles appeared in the online magazines. The nightmare gets a two page write-up in Dungeon #198, authored by Logan Bonner.
Some of the earlier characteristics of nightmares are restored here. They are again described (but not illustrated) as "gaunt", and there is a nod to their plane-shifting powers as a possible explanation of their ability to teleport short distances. Nightmares are again said to be predominantly solitary, except in the Shadowfell, where they hunt in packs. The predatory nature of the creatures is emphasized -- so grisly can the deaths of their victims be, that some of them remain behind as vengeful spirits.
The seemingly throw-away comment from the 3rd Edition Monster Manual that nightmares can invade dreams is repeated here, it seems that they somehow haunt the dreams of survivors of their attacks, as well as appearing in dreams as a foreshadowing of encounters still to come.
The damage inflicted by the nightmare's hooves has been boosted from 1d8+6 (plus 5 fire) damage, to 2d8+7 (plus 5 fire damage), and it is given a Shroud of Smoke defensive ability, which is another tip-of-the-hat to earlier editions. All nightmares can now travel to the Shadowfell, as well as take their rider with them when teleporting.
The discrepancy between their "lower" planar and Shadowfell habitats is addressed. The article makes it clear that in addition to the Shadowfell, there are also populations of nightmares in the Nine Hells and the Abyss. These herds are even given leaders. A stallion named Sin's Reward leads the nightmares of the Nine Hells. He wears spiked iron barding and is constantly surrounded by a cloud of black smoke and embers. Thunder of Hooves is a mare who has grown to enormous size, and mutated to grow an extra pair of legs. She rules over the herds of the Abyss by brute force.
Although these two rulers hate each other, they meet in the Shadowfell once each year to mate and produce three exceptional foals. One of these offspring remains on the Shadowfell, while the other two return to the home planes of each of their parents. The article suggests that these two rulers were originally servants of Vecna, but have been corrupted by their home planes, and that Vecna now plots their demise. The article finishes with a mention of the legendary Gloom Meet and the role that nightmare play in announcing this planar event. It is said that one way to find the location of the Gloom Meet is to follow the trail of scorched hoof prints.
This update does a good job of blending in traditional elements of nightmare lore, and it is a pity that it was published so late in the 4th Edition life-cycle. The 4th Edition Monster Manual would have been greatly improved by entries of this quality.
The 4th Edition of D&D is sometime viewed as the red-headed step-child, and 5th Edition a welcome return to the more classic lore of earlier editions. While this is often true, the 5th Edition nightmare (found in the latest Monster Manual) has more in common with its most recent sibling than any of its earlier cousins.
Now officially classified as a "fiend", a nightmare can attack only with its hooves. It lacks a bite attack and does not produce any form of smoke cloud. It has a fiery mane and tail, as well as the standard hooves wreathed in flames. It no longer creates a flaming path behind it, but it does burn brightly enough to illuminate the area around it.
Looking at the illustration, you'd be unlikely to use the words "skeletal" or "gaunt" to describe this beast. Nightmares remain willing to serve as steeds for exceptionally evil riders, but they require a sacrifice before they exhibit any level of loyalty to the creatures they serve. A nightmare's red eyes glow with malevolence. It is completely immune to fire, and grants fire resistance to any rider.
This nightmare cannot teleport like the 4th Edition version, but it has regained the ability to move to and from the Ethereal Plane, taking up to three willing creatures with it. It cannot travel into the Astral Plane. It is has recovered some intelligence, comparable to a typical human, and can understand three languages (Abyssal, Common and Infernal), but cannot speak.
The most notable change to the 5th Edition nightmare is the introduction of a completely new origin story. Nightmares are now created by removing the wings of a pegasus and transforming the noble creature to evil using dark magic. This lore comes out of left-field, and seems a little impractical. Once created, can nightmares breed with each other? If not, then who has been going to all the trouble of capturing pegasi to turn into nightmares? And to what end?
Ultimately, the 5th Edition nightmare is rather disappointing. It is mechanically rather boring, and what little lore is included in the Monster Manual is at odds with most of what we know about the creatures from previous editions.
Variants & Relatives
It seems that there are creatures very similar to nightmares, but which are not evil. In Setting Saintly Standards in Dragon #79, St. Bane the Scourger (a good saint, not to be confused with other D&D Banes) rides a white beast sharing the characteristics of a nightmare, but which is neutral good in alignment.
There is a similar white nightmare in The Dancing Hut of Baba Yaga, which glows "brilliant white like the sun". This is the steed of Light, one of the personifications of primal energy that Baba Yaga has captured as part of her plan to permanently evade death. When mounted by Light, the nightmare becomes insubstantial. Darkness (Light's counterpart) also has a nightmare which becomes insubstantial when ridden. This steed is the traditional inky black, but its coat is so dark that it seems to absorb all light. Both of these nightmares are neutral evil.
In Countdown to the Forgotten Realms in Dragon #277, the new champion of Zhentil Keep, Scyllua Darkhope, also rides a white nightmare. The Forgotten Realms Campaign Setting reveals the nightmare's name to be Targaraene. Although this seems to be an otherwise ordinary evil nightmare, its coat is not the only strangely coloured part of it. Both its eyes and hooves are imbued with blue flames. Unfortunately, by the time Darkhope and Targaraene make their final stand in the adventure Shadowdale: The Scouring of the Land, this detail has been forgotten, and the illustration shows a white nightmare with yellow flames.
The black unicorn (detailed in Unique Unicorns in Dragon #190) is also sometimes called a nightmare, but isn't a direct relative of the true nightmare. Similarly, the article Destriers of the Planes in Dragon #243 details nine magical steeds with planar origins, one associated with each alignment. Although none of them are noted as related to nightmares, the charnalbalk is an emaciated, coal-black equine with smouldering eyes, native to the Abyss, and some sort of common ancestry with the nightmare seems quite plausible.
The Planar Handbook details a lesser nightmare. This isn't the undead Mystaran creature we'll get to a little later, but simply a slightly less powerful version of a normal nightmare. The ability to travel the planes has been removed and replaced with the ability to always know where true north is. This has to rank near the top of a list of monster abilities least likely to ever to be relevant during a D&D game. The entry for the lesser nightmare includes a section on using it as a mount/servant for a blackguard. It's hard to view this uninspiring variation as anything other than an excuse to water down an ordinary nightmare to make it more balanced for use as player character's mount.
The Plane Below: Secrets of the Elemental Chaos mentions flame steeds, which are nightmares originating in the elemental plane of fire instead of the Shadowfell. These steeds serve efreets and fire giants.
Although nightmares do not have a deity of their own, they are associated with a number of gods. The original Deities & Demigods mentions their link to the god Hades, and Welcome to Hades in Dragon #113 notes that Hades' chariot is drawn by four nightmares, who are stabled on the roof of his palace.
An article on creating a pantheon of elemental gods (in Dragon #77) suggests that nightmares would be an appropriate creature to associate with the Fire God. Hypnatia, the Mistress of Dream, from Dreamlands: Variant Planes of Dreams in Dragon #287, is said to have thousands of children who tame nightmares.
Complete Divine lists cauchemar nightmares as allies of Nerull, and ordinary nightmares as allies of Vecna. The Master of the Hunt (a lesser god from Dragon #342) counts nightmares as his allies, and his herald, Herne the Hunter, also rides one.
Right out of the gate, the Monster Manual emphasises the role of the nightmare as a steed for D&D's traditional bad guys. Demons, devils, night hags, spectres, vampires and liches are are all given as example of creatures who use nightmares as mounts.
New Denizens of Devildom in Dragon #75 details a number of new arch-devils. Bathym (a Duke of Hell) rides a nightmare into battle, while Alocer (another Duke) considers his nightmare as suitable for travel about his estates, as well as when going to war. The arch-devil Mammon rides a nightmare of largest size. He is still riding it in 1999's Guide to Hell.
When encountered in OP1: Tales of the Outer Planes, Asmodeus is riding a nightmare. Nine Hells Revisited in Dragon #91 notes that devils appoint intermediaries (dark nagas, hell cats, imps, and the like) to command nightmares on their behalf. The same article notes that nightmares (and other mounts), are difficult to transport on the River Styx. They must be blindfolded and made to lie down, and the charonadaemons will charge a triple fare for the required space.
Narzugon devils are probably the fiends most associated with the nightmare. First introduced in the 3rd Edition Manual of the Planes, they are consistently depicted astride the evil equines. They have mastered the art of mounted combat, and tend to be protective of their steeds, withdrawing from combat if their nightmares becomes seriously injured. In 4th Edition, narzugons are known as hell knights, and are servants of Asmodeus. The illustration in the Monster Manual 3 shows one riding a somewhat skeletal nightmare, a rarity for later edition artwork.
Other fiends have also been known to use nightmares as mounts, including mezzodaemons (Dragon #113) and succubi (Fiendish Codex I).
Another creature with a strong link to nightmares is the hag. The annis hag Vyedma uses a nightmare as a steed in I8: Ravager of Time as does Nuala, the resurrected sorceress who is one of the main protagonists of the adventure. Nuala also has a Leomund's secret chest which is guarded by a nightmare. If the recalling chest is used to return the secret chest by anyone other than Nuala, the nightmare appears and attacks. It retreats to the ethereal plane once seriously wounded.
The Monster Manual v.3.5 mentions that night hags ride nightmares, and they are depicted together in the The Ecology of Night Hags in Dragon #324.
One of the most powerful hags in D&D history was Malagarde, the Hag Countess, appointed by Asmodeus to rule over the hellish layer of Malbolge for a time. Fiendish Codex II notes that once Asmodeus's daughter Glasya took over control of Malbolge from the Hag Countess, she also tried to co-opt the hag's steed, a monstrous nightmare named Bloodcurdle. Although this steed initially pretended to accept its new mistress, it then threw Glasya into one of the Lakes of Bile. As a consequence, Bloodcurdle now faces a gruelling schedule of torments each day. He's still being tortured by Glasya in 4th Edition (Dungeon #197).
Death knights are also closely associated with nightmares. According to the original Fiend Folio, they can summon replacements every ten years.
Perhaps because of their astral travelling ability, Githyanki have been linked to nightmares since 1st Edition. OP1: Tales of the Outer Planes includes an astral encounter with a group of githyanki knights riding huge nightmares. The description of the stables here includes piles of molten rocks and troughs of boiling lava, but it isn't clear if these are needed to care for the nightmares, or a byproduct of their residency. A Guide to the Astral Plane notes that githyanki knights tend to ride nightmares into battle only when their combat abilities are important, because the knights are faster when unmounted.
olyhedron #159 includes a d20 mini-game which allows players to take on the role of githyanki invading a human world. One of the feats available to these characters allows them to replace their fiendish servant with a nightmare steed.
In 4th Edition, even though nightmares can no longer travel to and from the Astral Plane, the connection to githyanki remains. They serve as steeds for high-level githyanki in several sources (Monster Manual, Dragon #377, The Plane Above: Secrets of the Astral Sea).
Arch-fiends, hags, death knights and githyanki seem to make the most use of nightmares as mounts, but throughout D&D history, a wide variety of other creatures have ridden them. The Battlesystem Fantasy Combat Supplement mentions that drow elves may ride nightmares, and the Dungeoneer's Survival Guide expands this to races of the Underdark in general, many of which employ nightmare steeds.
In the 3rd Edition Manual of the Planes, powerful members of the Unseelie Court ride nightmares during their Wild Hunts. Nightmares are also ridden by the banesworn, the servants of the Iron General of Chernoggar in The Plane Above: Secrets of the Astral Sea.
Other nightmare riding creatures include shades (C6: The Official RPGA Tournament Handbook), tieflings (Dungeon #116), wights (4th Edition Monster Manual), medusas (DDEX2-04: Mayhem in the Earthspur Mines), mummy lords (DDEX3-16: Assault of Maerimydra) and in 4th Edition particularly, powerful shadar-kai (Monster Manual 2). Enemies and Allies has Strabo, a half-dragon cleric of Erythnul, riding a nightmare. Riders are not limited to medium-sized creatures. The adventure Demonblade in Dungeon #97 has a nightmare ridden by a nine-foot tall troll.
Some creatures are fated to be mere caretakers of nightmares. The nightmares in Expedition to the Demonweb Pits are being looked after by babau demons, and appointing minor demons and devils to do this job isn't uncommon. In The Dancing Hut (Dragon #83), the three nightmares stabled in Baba Yaga's hut are watched over by four diakkas. More than 25 years later, in Dungeon #196, her nightmares are still being looked after by diakkas, although there are now only three of them.
Slasraths, ray-like flying creatures of Gehenna (described in Planes of Conflict) seem to be about the only creatures that view nightmares as food, but then slasraths will eat almost anything. Planes of Conflict also mentions that the mighty baernaloths sometimes have nightmares as companions.
The shadow unicorn, from Ravenloft Monstrous Compendium Appendix III: Creatures of Darkness is said to be able to speak the language of nightmares, even though nightmares are not know to speak a language of their own. Finally, the blood fiend (from City of the Spider Queen) has the ability to become a nightmare as an alternative form.
Nightmares and magic
Although it seems creatures of the lower planes can readily use nightmares as mounts, the Monstrous Compendium Outer Planes Appendix contains a rather convoluted process for Prime Material Plane residents to secure one as a mount. A wizard of at least 5th-level must start by casting a mount spell to attract the attention of the nightmare, followed by a monster summoning III spell, and then finally a wall of fog, after which a nightmare will come galloping out of the mists. Once this is done, anyone (not just the caster) can offer the nightmare oat-like flakes of platinum worth at least 200 gp in value to secure its services for 72 hours.
Apparently, this isn't the only way to call a nightmare into the world. Labyrinth of Madness has a statue which uses a special version of monster summoning to summon various monsters, include a nightmare. In the article Pleasant Nightmares! in Dragon #186, a nightmare haunts a castle built on an ancient evil unholy spot. Its appearance can be stopped using an exorcism spell, but this only works half of the time.
In 3rd Edition, the core spell Lesser Planar Binding, combined with a Dimensional Anchor and Magical Circle Against Evil, can call a Nightmare to negotiate with (or, as mentioned above, immediately slay to reanimate as a skeleton). Despite this, the The Book of Vile Darkness has a call nightmare spell. It is a demonologist spell, but is also available to sorcerers and wizards. The summoned beast remains in service for a week, or until the caster moves more than 150 feet away from it. The catch? The material component for the spell is a soul! If a soul seems a high price to pay, the alternative summoning rules in The Summoner's Circle in Dragon #302 allow a spellcaster to expand the list of creatures summonable using summon monster V to include a nightmare with only a few days of research.
Also worth a mention is the conjure nightmare spell from Dragon #221. This spell summons a nightmare which serves willingly as long as it is given only evil tasks to do. It will rebel if given tasks that do not have an obviously malicious purpose. The spell is quite expensive to cast, requiring 200 gp of platinum flakes. More importantly, the nightmare is not summoned from the lower planes, but from the Plane of Dreams, where it is plucked from a random sleeper's nightmares. This means that the nightmare only remains summoned until that sleeper awakens, which could prove rather inconvenient, since the caster has no control over which sleeper's dream the nightmare is plucked from.
Nightmare parts as components
In The Ecology of the Cockatrice in Dragon #95 mentions that the blood of a nightmare is one of several potential components required to make a liquid capable of magically preserving cockatrice tail feathers.
The mystic rope spell (Wizard's Spell Compendium Volume III) requires a miniature rope of braided hairs from the mane of a nightmare as its material component. Accord to Ecology of the Scarecrow in Dungeon #183, hairs from a nightmare's mane are also woven into "nightmare thread" by hags. Laced with the filaments of dark dreams, this thread is used to stitch together a scarecrow and keep its spirit bound within the cloth and stuffing. If an adventurer somehow obtains some of this precious commodity, burning the thread turns him or her into a terrifying vision in the eyes of an enemy.
In Dragon #147, hoof of a nightmare is listed as an alternate component for the illusionist's phantom steed spell. This improves the capabilities of the steed by one level. However, with a price tag of 5,000 gp per hoof, and low availability (an alchemist has only a 5% chance of having 1-4 hooves), this seems more like a business opportunity for a nightmare-hunting adventuring group than it does a viable boost for the group's illusionist. Especially since that's not the only use for the hooves. Dragon #317 expands on the optional rules for power components as a replacement for spell XP costs, mentioned in the Dungeon Master's Guide v.3.5. The hooves of a cauchemar nightmare (all four) can be used for a planar ally spell. In order for the hooves to remain useful, they must be stored in a jar filled with a special oil that allows the supernatural flames to continue burning.
In Ringing in the Deep, a tournament adventure for GenCon 2010, the heart of a nightmare can be wielded against a cinderhoof trampler to give a number of special bonuses. The cinderhoof trampler is a minotaur variant (from the Monster Manual 3) who has eaten the heart of a nightmare in order to gain burning hooves. However, using a heart as a weapon against a minotaur seems to be something unique to this adventure.
Nightmarish magic items
Nightmares are the inspiration for several magic items, including some things typically found in stables. Bazaar of the Bizarre in Dragon #47 details the horseshoes of Hades. When all four are attached to the hooves of a normal horse, it is transformed into an uncooperative and likely hostile nightmare.
The nightmare harness from Dragon #234 is a magic item made by a lich in order to summon a nightmare. It is studded with platinum and precious gems which glow with an inner fire. Once summoned, the nightmare will serve the lich indefinitely, but should the nightmare die while in service, the harness crumbles to dust.
Also capable of summoning a nightmare is the darkest bridle from Dragon #244. Made of black leather studded with onyx, when cracked against the possessor's leg, the bridle summons a flying steed. The creature summoned is determined randomly, with a nightmare the least likely monster to appear. A saddle of the nightmare (detailed in Adventurer's Vault) allows the rider of a teleporting mount to travel with the steed, even if that would not normally be the case.
There are at least two types of magical figurines which transform into nightmares. The most well-known of the two is one of the figurines of wondrous power first detailed in the 1st Edition Dungeon Masters Guide. There it is described as a "small, nearly shapeless lump of black stone" vaguely resembling a quadruped. The obsidian steed figurine becomes a nightmare upon the utterance of the command word. It will allow itself to be ridden, but should the rider be of good alignment, there is a 10% chance that he or she will be dropped off in Hades.
Bizarrely, the description of the obsidian steed in the Dungeon Master's Guide v.3.5 makes no reference to nightmares. Instead, it says only that the steed transforms into a "fantastic mount" capable of travelling to the Astral and Ethereal Planes. The goat of travail figurine, however, becomes an enormous creature with the statistics of a nightmare. In the 5th Edition Dungeon Master's Guide the figurine is back to changing into a nightmare, but the workmanship has improved, since the illustration clearly resembles a horse.
The second type of figurine is the equus, introduced in Dungeon #22. This is a magical piece of jewelry that polymorphs on command into a beast of burden. Although a nightmare is not one of the standard options for creatures into which the equus polymorphs, it is mentioned as a possibility for an evil version of the item.
One of the four functions of a wand of darkness, first detailed in Dragon #102, is to summon a nightmare. This costs three charges. The nightmare is under the control of its summoner, and serves for 90 minutes. It can transport a rider to the Astral or Ethereal Planes. A staff of fiendish darkness (Magic of Faerûn) can be used to summon a nightmare at a cost of two charges. (This item was renamed to be a runestaff of fiendish darkness in the Magic Item Compendium.)
The warrior Ardenor Crush, who has been reincarnated into the body of a hobgoblin, is detailed in FR15: Gold & Glory. He wears an amulet that allows him to summon a nightmare. In Marco Volo: Arrival, the malevolent artifact known as the Dragonking's Eye is in possession of transport gems that can be used to summon extra-planar allies, including a nightmare.
Dragon #76 notes that although a potion of fire resistance is ineffective against the most powerful of devils, it does work against the magical fires produced by a nightmare. The article The Many Facets of Gems in Dragon #83 states that diamonds are supposed to provide protection from creatures like spirits, ghosts and nightmares.
Finally, one of the many creatures into which a paddleboard of wondrous transformations can polymorph its target is a nightmare. This item is detailed in Dragon #134.
- http://www.enworld.org/forum/content.php?3807-Monster-ENCyclopedia-Nightmare: An exhaustive examination of the nightmare through the ages, including relevant artwork, edition vs. edition stat comparisons, and a setting-by-setting reference list.