An in-depth look at the origins of the shadow and the influernce of A. Merritt's novel, Creep, Shadow, Creep!, in Dungeons & Dragons.
The original pulp appearance of Creep, Shadow, Creep! in 1934 (right), and a 1942 reprint (left).
Most classic undead monsters featured in the Dungeons & Dragons game originate from the realms of mythology and folklore. Novice players joining a game for the first time usually a modicum of knowledge of zombies, skeletons, ghosts, spectres, vampires, mummies, and other undead horrors from countless books and movies. However, a few undead found in the game have no such folkloric basis. Two notable examples are wights (derived from Tolkien), and the lich (derived from Gardner F. Fox) . A third example is the shadow, which derives directly from Abraham Merritt’s novel, Creep, Shadow, Creep!.
The Sorceress of Shadows
Creep, Shadow, Creep! (also known as Creep, Shadow!), along with other Merritt novels, is listed on Gary Gygax’s Appendix N list of inspirational reading.  First published in 1934, this novel combines elements of fantasy with horror, much like its predecessor novel, Burn, Witch, Burn!.  Set in New England in the then present of the 1930s, this novel reads like a Lovecraft story — albeit with much more women, sex, psychological musings, and adjective-laden, phantasmagorical imagery.  The novel’s protagonist, Alan de Caranac, is a scientist and explorer who meets a young woman named, Demoiselle D’Ys (usually referred to as Dahut), and her father, Doctor de Keradel. Unbeknownst to Alan upon first meeting, Dahut is a witch, and her occultist father is sorcerer. As with nearly all of Merritt’s stories, the male protagonist has an irresistible attraction to the powerful — yet evil — female antagonist. Alan is no exception to this. His attraction to the beguiling Dahut is cemented when she tells Alan they are reincarnated lovers from the fabled city of Ys. However, Alan is wary of Dahut, and the power she seems to possess. He believes that she had a role in the death of close friend, who died after telling Alan that he was being stalked by a shadow intent on killing him. As Alan learns more of the mysterious Dahut and her father, he discovers that she uses magic to create human shadows from living people. The “Queen of Shadows”, as she is called, then commands them to slay her enemies. Additionally, she and her father wish to recruit Alan in summoning a shadowy being, called the Gatherer, to New England with the intention of recreating the glories of old Ys. They summon of this being with dozens of human sacrifices.
Let’s take a look at how shadows in D&D compare with those found in the novel. Shadows were mentioned as a type of monster in the original 1974 D&D three book box set, but were not detailed until 1976s Greyhawk Supplement.
Form: The book notes that shadows are semi-corporeal, and can be touched. The 1st edition Monster Manual never specially states that shadows are semi- or non-corporeal, only that “they exist primarily on the negative material plane”. However, other D&D books (i.e. Greyhawk Supplement, Holmes Basic set, Moldvay Basic set, and Mentzer Basic set) are clear that shadows are “non-corporeal” or “in-corporeal”. (See my article, "A Guide to Undead in AD&D", for a comprehensive look at undead in the AD&D game.)
Lurking in Shadows: In the novel, the shadows appear as dark silhouettes that can slip into and out of areas unseen. This attribute appears in the Monster Manual where it is noted that shadows are all but undetectable in all but the brightest of light.
Killing Touch: The shadows in Creep, Shadow, Creep! feed on the living. Presumably, this is how they slay the living, though the novel never specifically mentions the method. Those slain by a shadow, like Alan’s friend, rise again as a shadow under the control of Dahut. In D&D, shadows feed on the life force of the living. In the term of game mechanics, they drain Strength points. Those fully drained of Strength then become shadow themselves.
Appearance: The novel describes some shadows as appearing as a normal human’s shadow, while others are described as looking like the shadows of men but “deformed, distorted, changed into abominable grotesques”. Some are black, while others have a pale or silvery sheen, or are pinkish, deep blue, green, or gray-hued. In D&D, the physical appearance of shadows is never noted, other than they look like a person’s shadow, and no illustration is found until 2nd edition’s Monstrous Compendium. Oddly enough, the illustration in that book is of a shadow with an “abominable grotesque” appearance. I have no idea if that was an intentional reference to the novel, or not.
The shadow as an “abominable grotesque” from the Monstrous Compendium.
As Undead: The novel never explicitly explains how Dahut creates and commands her shadows, other than using unnamed sorceries. References in the book intimate that shadows are semi-living beings. However, the shadows that inhabit in the Shadow Realm (see below) are surprised that Alan is not dead when he visits here. The reader is never given a definite answer whether or not these shadows are the same as the ones found in the “real” world, or some just an aspect of them. In the Greyhawk Supplement and “Basic” D&D books, shadows are noted as not being “undead, per se”, and they do not appear on the cleric’s undead turning tables. It wasn’t until the 1st edition Monster Manual that shadows gained full undead status, with clerics having the ability to turn them. Second edition’s Monstrous Compendium entry for the shadow contain some vestiges of the evil magic used to create shadows as hinted at in the novel. Here, it explains that shadows were possibly originally created by a magical curse, and that it might be possible to reverse the shadow form of the victim.
Other Influences from Creep, Shadow, Creep!
The Plane of Shadow: In the novel, the protagonist, Alan de Caranac, is transports by one of Dahut’s spells to a mysterious dark realm made of semi-solid shadows. Living shadows looking to feed on other shadows populate this realm. These shadows are trapped there by sorcery, such as a strange medieval warrior-shadow riding a shade horse who had been there for six hundred years. It seems likely that this realm was the inspiration for AD&Ds Plane of Shadow.  The Plane of Shadow was first mentioned in Gary Gygax’s “From the Sorcerer’s Scroll” article in Dragon Magazine #37 (May 1980).  It received a short paragraph in the Deities & Demigods Cyclopedia where it is mentioned as “…a place of distorted and mutable shadow-creatures, of white, black and all shades of gray.” After this, the Plane of Shadow receives little attention in official works other than a few scattered references the Unearthed Arcana (where it is also referred to as “Shadowland”), and a short description of the “Demi-Plane of Shadow” in the Manual of the Planes (which places the plane as a sub-area of the Ethereal Plane).
Shadow Mastiffs: In addition to human shadows, the sorceress, Dahut, keeps a pack of terrifying supernatural shadow hounds on her estate. These hounds have a frightening bay, red eyes, and shadowy appearance. Their bite causes a numbing cold weakness like D&Ds shadow’s Strength draining touch. No doubt that Dahut’s hounds were the direct inspiration the shadow mastiff from Monster Manual II. It is worth noting that these creatures originate from the Plane of Shadow.
The statistics and illustration of the shadow mastiff from Monster Manual II.
Shadow Illusions: The 1st edition Players Handbook details a number of illusionist spells connected to, or that pertain to, the use of magic drawn from shadows. However, not until the publication of the Unearthed Arcana is this type of magic connected to the Plane of Shadow (specifically, in the description of shadow walk). One might surmise that other forms of shadow-based magic in the PHB (e.g. shadow monsters, shadow magic, etc.) would also derive their energies from a connection to the Plane of Shadow. However, while alluded to, a definitive connection was never in the AD&D game. Please note that I am not suggesting that shadow-based illusionist magic derives from any specific magic Dahut used in the book. Rather, that the sorceress manipulated illusions and shadows served as an inspiration for this type of illusionist magic in D&D.  Well, that, and some of the magic used in Roger Zelazny’s novel, Jack of Shadows. 
A curious illusionist spell that demands a closer look is summon shadow. This spell seems to be a vestigial remnant of the shadow’s original non-undead status in D&D. This spell is an anomaly in that magic-users in 1st edition AD&D have few powers that deal with undead (usually the domain of clerics).  It also seems to echo Dahut’s ability to call on shadows to do her bidding. The spell does not state that where the shadow is conjured up from, however.
1: The lich originally appeared Fox’s sword-and-sorcery novel, Kothar, Barbarian Swordsman, published in 1969. It is possible that the Fox’s lich was inspired by the undead wizard that appears in Robert E. Howard’s Conan novel, Hour of the Dragon, as his fantasy works bear a strong resemblance to Hyperboria. Another possible source of inspiration could stem from the undead arch-mages in Clark Ashton Smith’s Zothique and Posidonis stories. Look for more on the history of the lich in a future post.
2: I find it odd that Gygax regards Lovecraft as a major influence on D&D when there are few specific game elements can be attributed to him. Instead, Lovecraft’s influence is more thematic than specific. In contrast, many specific elements from Merritt’s works have made their way into the D&D game.
3: Published in 1932, Burn, Witch, Burn! seems to be the origin of the murderous doll trope that exploded in later decades in horror books and movies. The story concerns a doll shop owner who, in reality, is a witch. She animates the dolls to murder her enemies.
4: That Merritt’s works were highly influential on Lovecraft’s stories is well-documented. Lovecraft was a fan of Merritt’s novels. His story “The Moon Pool” is regarded as an influence on “The Call of Cthulhu”; Merritt’s stories often featured explorers searching old ruins; he often used the word “cyclopean”; the city in Merritt’s “People of the Pit” is an obvious influence on the city of the Elder Things in Lovecraft’s “At the Mountains of Madness”, just to name a few.
5: Another source of inspiration for the Plane of Shadow is probably the “darkside” of the planet featured in Roger Zelazny’s novel, Jack of Shadows (also an Appendix N book).
6: Gygax notes that Skip Williams was working on a module that he outlined titled, Shadowland. Set to be released in late 1980, it would have been “…an adventure on the Plane of Shadow — perhaps that should be Quasi-plane of Shadow.” There was even mention of future modules connected to it being produced. Seems like Gygax had big plans for the Plane of Shadow. I wonder what became of that module, and why it was not released?
7: Two scenes in the book depict Dahut casting spells by singing. In one, she casts a spell that either hypnotizes Alan, or causes him to see real illusions. The book is vague on specifics with magic, due to Alan never really being sure of what he sees and experiences is true reality or sorcery.
8: At one point in Zalazny’s novel, Jack uses shadows to travel far, much as the illusionist spell, shadow walk.
9: This spell originally appeared in The Strategic Review #4, along with the illusionist spell, create spectres. This spell as later dropped when the class was added to the 1st edition Players Handbook.
Grubb, Jeff. Advanced Dungeons & Dragons Manual of the Planes. TSR, 1987.
Gygax, Gary. Advanced Dungeons & Dragons Dungeon Unearthed Arcana. TSR, 1985.
Gygax, Gary. Advanced Dungeons & Dragons Monster Manual. TSR, 1977.
Gygax, Gary. Advanced Dungeons & Dragons Monster Manual II. TSR, 1983.
Gygax, Gary. Advanced Dungeons & Dragons Players Handbook. TSR, 1978.
Gygax, Gary, “From the Sorcerer’s Scroll, Greyhawk: The Shape of the World,” Dragon magazine, Issue No. 37 (1980): p. 10.
Merritt, Abraham, Burn, Witch, Burn!/Creep, Shadow, Creep!, Leisure Books, 1996.
Robinson, Weinberg, & Broecker, Art of Imagination, Collectors Press, 2002.
Stewart, Doug. Advanced Dungeons & Dragons Monstrous Compendium. TSR, 1993.
Ward & Kuntz. Advanced Dungeons & Dragons Deities & Demigods Cyclopedia. TSR, 1980.