Table of Contents
This is an update to bring the original Cthulhu content that was written over 40 years ago inline with todays Dungeons and Dragons 5th Edition (a.k.a. 5e evergreen).
The Cthulhu Mythos was first revealed in a group of related stories by the American writer H. P. Lovecraft. Beginning with “The Call of Cthulhu” in Weird Tales, Lovecraft began referring in his horror stories to a pantheon of beings known as the Old Ones, who had descended to Earth from the stars in pre-human times. First worshiped by the non-human races of the planet, the Old Ones were later banished or locked away by the elder gods.
The elder gods do not enter into the stories much, and their identity is a mystery. They left the Old Ones weakened, but not destroyed. When man appeared, he found traces of the older civilizations and remnants of the pre-human races. Religions grew up around the Old Ones and legends of their imminent return to power- especially around Cthulhu. Bits of the old lore were discovered and transcribed into books – extremely dangerous books.
Cults of men, and particularly of non-human creatures, keep alive the worship of the Great Old Ones and anxiously await their return to power. Various evil wizards and priests, desirous of superhuman powers, experiment with some of the forbidden books (such as The Necronomicon) and occasionally unleash some horror on themselves or their surroundings.
Merely speaking the name of one of the Old Ones results in a 5% (natural 20 on a 1d20) chance that the god named will hear, for these deities are quite attuned to the Prime Material Plane. If the god does hear its name spoken, it will appear and attempt to kill the being so rash as to speak its name (some of the greater gods will send minions to accomplish this: Dungeon Master has ultimate authority on these guidelines).
All creatures of nature are very sensitive to the presence of all creatures of the Cthulhu Mythos. They instinctively call out their warning sounds and flee if any of the Old Ones or their minions come within range of their senses.
To create Challange Ratings use this calculator at DnDink: https://dndink.com/dnd/crcalculator.html
AC: 18 Abilities: Fighter 26nd Level, Magic Resistant HP: 800
Cthulhu is a bloated humanoid form 100 feet high with an octopoid head and a face of tentacle-like cilia (has 45 tentacles for up to 30 attacks per round at 1d10 damage per tentacle attack). It has scaly, rubbery skin, and prodigious hands and feet with curved talons. A pair of folded bat-like wings protrude from between its shoulders.
“Ph’nglui mglw’nafh Cthulhu R’lyeh wagh’nagl fhtagn.”- “In his house in R’lyeh dead Cthulhu waits dreaming.” R’lyeh is a great sunken city of non-Euclidian geometry hidden somewhere beneath the ocean. So bizarre is its construction that anyone entering the city (which occasionally rises above the waves) must make Saving Throws DC 18 against Fear and Madness.
Cthulhu lies in a huge stone structure sealed with the Elder Sign (see below). If the seal is broken and the god released, everyone (and/or every thing) in a radius of 100 miles must make a Saving Throw DC 10 against death or go insane. This insanity (madness) lasts for a number of days equal to the creature’s intelligence.
Cthulhu usually attacks both physically and psionically. He can regenerate 10 hit points per melee round. He teleports up to one-half mile at will and is totally immune to the effects of water, cold, and vacuum. He can call up from the sea 10-100 of the Deep Ones. He will retreat into his lair if confronted with an intact Elder Sign, another of the Old Ones (such as Hastur), or some natural catastrophe, such as there sinking of the city of R’lyeh into the sea.
Cthulhu is served by the Deep Ones as well as his human worshipers, who often interbreed with the fish-men. Cthulhu’s cult is usually hidden and secret and is dedicated to bringing about Cthulhu’s return and conquest of the world.
Azathoth (the center of the universe)
AC: 22 Abilities: Fighter 35th Level, Magic Resistant HP: 1200 INT: 0 WIS: 0
Azathoth is a blind, mindless, amorphous mass the size of a star, floating at the center of the universe on the astral plane. It is attended by satellite creatures that provide an eerie music, like the sound of idiot flute players. Azathoth is somewhat solid near the center, and can be attacked there, but it will defend itself with its many pseudopods if so attacked. Any creature coming within 1,000 miles of Azathoth must save vs. spells DC 17 or go permanently mad.
Those who worship Azathoth worship insanity, and Azathoth’s clerics are themselves insane. It is unknown how Azathoth grants powers to its clerics, or even if Azathoth is aware of them (which is doubtful).
Byakhee (servants of Hastur)
AC: 11 Abilities: Fighter 6th Level HP: 120 Attack Damage: 1d10
These giant furry bat-like creatures have humanoid legs that enable them to stand like men. They can be summoned by clerics of Hastur through use of a gate spell (1-4 Byakhee will appear). They are able to teleport throughout the Prime Material Plane at will, carrying human beings with them on their backs or in their talons. They are intelligent, telepathic, and will obey those who carry the Elder Sign or who appeal successfully to Hastur.
Cthuga (master of the fire element)
AC: 26 Abilities: Fighter 23nd Level, Magic Resistant HP: 730
This creature resembles a flaming amoeba with tentacles that appear to be flames emanating from its body. The heat of Cthuga’s body does 5-50 points of damage to all within 100 yards of it, and it attacks with fire spells at the same time. It cannot be controlled and is immune to all heat and cold attacks. It is able to cast any fire spell of any type as a 30th level spell caster, at the rate of two per round.
While casting fire spells, it also lashes out with two of its tentacles per melee round; these do 3-30 points of damage each. It moves as a blink dog and attempts to destroy everything within any area to which it is summoned. When appearing in any location, its first act is to summon 1-20 of its flame creatures. Cthuga can only be struck by +1 weapons or better as all others melt when touching him.
The creature has a direct connection with the Prime Material Plane by way of a Palace of Fire that it has created in an active volcano. This palace is said to be filled with treasure resistant to flame and heat: gems, certain magic items, and the like.
Cthuga’s Flame Creature
AC: 20 Abilities: Fighter 9th Level HP: 80
These creatures appear to be smaller versions of their master. Their bodies radiate 10 points of heat damage to all who come within 20 yards of them, and they can cast a single heat ray from their body every melee round that does 2-20 points of damage if it hits. One of their functions is to appear when the god is supposed to appear but is too busy or chooses not to come.
Deep Ones (followers of Cthufhu)
AC: 16 Abilities: Fighter 4th Level HP: 28
The Deep Ones are humanoid, amphibious men-fish, cold-blooded creatures of great strength (STR 18). They can attack with their clawed, webbed hands, or wield weapons. They have infrared vision as well as normal sight. They live near the land on ocean shelves and ore able to travel to the land at any time and for as long as they wish.
They have been known to interact with evil humans and interbreed with them. This results in human-appearing offspring who undergo a gradual transformation after the age of 21 that causes them to become as the Deep Ones who spawned them. The Deep Ones ore soulless and apparently immortal.
These creatures promote evil in preparation of Cthulhu’s return. They do this by collecting treasures from the sea and using them as funds to spread the cult of Cthulhu and the Old Ones.
Hastur the Unspeakable (He Who Must Not Be Named) “Master of the Air”
AC: 22 Abilities: Fighter 28th Level HP: 890
This god has a scaled, elongated body, a lizard’s head and maw, and taloned lizard claws. It also has 200 tentacles projecting from its body that give it the ability to sense all things around it. It is able to strike twice per round and also attack magically.
At will, it can teleport anywhere in the Prime Material Plane. Hastur regenerates 5 hit points per melee round, and can summon 2-20 Byakhee to aid it in bottle. It cannot be magically controlled. Creatures that are able to fly naturally will never attack Hastur, even if controlled. Any being trying to attack the god must make a saving throw against fear DC 16.
Hastur is half-brother to Cthulhu, and like him Hastur has been imprisoned by the star-shaped Elder Sign. He lies in a crypt at the bottom of Lake Hali near the alien city of Carcosa. Hastur exists partly on the Prime Material Plane (and this part is imprisoned in the crypt) and portly on the Elemental Plane of Air (thus he is immune to cold and the vacuum of space). Hastur is never mare than partially on the Prime Material Plane and is therefore not completely solid. This accounts for much of his great size.
Any time the name “Hastur” is spoken, there is a 5% chance (natural 20 on a 1d20) that Hastur will hear and send 1-4 Byakhee to slay the speaker. If the Byakhee are defeated, there is a 25% (natural 4 on a 1d4) chance that Hastur himself will appear to destroy the blasphemer.
Ithequa (lord of the air)
AC: 18 Abilities: Fighter 13th Level HP: 180
lthaqua, the Wind Walker, appears as a cloud of fog or snow, huge but human in shape with blazing red eyes. When seen passing overhead, one gets the illusion of two bright stars close together.
lthaqua is worshiped by the natives of the far North because of his ability to control weather (triple the range and effects). His worshipers propitiate him with human sacrifices, which he carries off, no one knows where. Years later, their frozen bodies are sometimes found buried in snow drifts. lthaqua will also pursue and capture anyone who sees or annoys him or meddles with his worshipers or their stone altars in the forest. Sometimes his victims return to earth alive, but they never survive long as they die from strange unnatural causes.
It is known that lthaqua serves Hastur in special missions of great importance.
Mi-Go (the Fungi from Yuggoth)
AC: 16 Abilities: Fighter 3rd Level HP: 27
These red, bot-winged creatures somewhat resemble lobsters in that they have many legs, feelers, and eyestalks, and forearms that end in great pincers. Though they appear to be crustaceans, they are actually fungus creatures. Mi-Go are immune to the effects of cold, dark, and vacuum, and can fly across interstellar space. They cannot speak but communicate by clicking their pincers.
Nyariathotep (the crawling chaos, the messenger of the gods)
AC: 18 Abilities: Fighter 18th Level HP: 320
Nyorlothotep appears as a tall dark man. His appearance in the world is said to foretell the return of the Old Ones from their imprisonment. He charms humans, humanoids, and non-magical animals by his mere presence (good alignment, save DC 10; evil alignment, save DC 14). Those falling under his spell either obey him or behave in a purely chaotic manner. Thus, his progress across the face of the land is followed by riot, war, moss murder, suicide, and insanity. No non-sentient creature can harm him, even if controlled.
The god is believed by some students of the occult to have various guises, including a red bat-like form with three evil eyes. He can call up an army of wild beasts or mindless humans within an hour’s notice (1-100 of them). Each time Nyarlathotep hits an enemy, he drains 3-30 hit points from them, which temporarily add to his hit point total for one full turn. There is a 15% chance that any “light” spells will drive this being off into the Astral Plane.
AC: 19 Abilities: Fighter 15th Level, Magic Resistant HP: 145
Originally created by the Primordial Ones as servants, the Shoggoths eventually rebelled and destroyed the civilization of their masters. Shoggoths resemble huge, intelligent amoebae, able to form almost any shape out of their near-transparent bodies, including legs, eyes, mouths, huge weapons, or whatever is needed. The few remaining Shoggoths lurk in distant, long-deserted areas, sometimes aiding servants of Cthulhu or other Old Ones.
Shub·Niggurath (block goat of the woods with a thousand young)
AC: 16 Abilities: Fighter 19th Level, Magic Resistant HP: 750
This fountain of uncleanliness is a huge pool of gray matter, 100 feet across, in the caverns beneath Mount Voormithadreth. It is constantly bubbling and putting forth mouths, limbs, pseudopods and whole creatures. 1-100 small monsters are created from the pool each round, and they go crawling, flopping, or flying away into the caverns above. Some fall bock into the pool, which then grows mouths and devours them.
Shub Niggurath is intelligent and telepathically sensitive. When it senses the approach of enemies (range 1 ,000 feet) it will begin creating monsters to defend itself, one per melee round. These will be random according to the following (1d4): 1. Byakhee; 2. Deep One; 3. Mi-Go; 4. Shoggoth.
If any enemy is so foolish as to approach to within 60′ of the being, will lash out with a huge powerful tentacle; if it hits, it will pull the unfortunate victim into the pool, where they will immediately be come part of the evil swirling protoplasm. Any creature struck has a per centage chance of not being pulled into the pool equal to his or her strength. Shub-Niggurath strikes only once per turn in this way and con simultaneously create monsters.
Though its body is trapped deep in the caverns, Shub-Nigguroth travels the Prime Material Plane in astral form, using its psionic powers to do evil and aid its worshipers.
Yog-Sothoth (the key and guardian of the gate)
AC: 22 Abilities: Fighter 20th Level, Magic Resistant HP: 800
Yog-Sothoth exists on the astral plane. He has the ability to enter the universe at any point in space and any point in time. His astral shape appears as a congeries of iridescent globes like giant soap bubbles. When he takes shape on the Prime Material Plane he is partly material and partly astral and appears as a gigantic mass of feelers, legs, and stalked organs. In this shape he will mate with human beings, producing the Spawn of Yog-Sothoth (see “The Dunwich Horror”, by H. P. Lovecraft).
He is highly intelligent and extremely chaotic and unpredictable. He can gate in and out of time and space any of the Spawn or subject races of the Old Ones, one per melee round. Yog-Sothoth is not subject to the laws of space and time and can, for example, appear at various parts of the universe simultaneously.
The Elder Sign
This small grey (sometimes greenish) stone in the shape of a five-pointed star is a powerful protection against all minions of the Old Ones. The true potent Elder Signs are few in number and incredibly ancient, having been made by the elder gods. They have the following powers: they are 100% protection against psionic attacks; a force that will drive off all Shoggoths, Byakhee, Flame Creatures, Deep Ones, and Mi-Go, when presented; and while they will not stop the persistent efforts of any of the more powerful masters, they will provide a +3 protection against their attacks (as a ring of protection).
The Elder Signs are highly resistant to destruction – AC 22 – broken only by magic or by incredible force. The Elder Sign was used by the elder gods to seal off those places where the Great Old Ones were imprisoned or where they had a chance of “breaking through” in force to the Prime Material Plane.
The Necronomicon is a powerful and perilous magical tome of ancient origins. It was originally written by Abdul Alhazred, a great magic-user known to some as “the Mad Arab”. After ten years alone in the desert he wrote a book called AI Azif- words used to denote the nocturnal sounds of insects which may be the voices of demons. Alhazred was later seized in the streets of a desert city by invisible demons and devoured horribly in front of many witnesses. Those who have studied his writings have some times met a fate nearly as terrible. The book was banned, and all known copies were destroyed, but a few translated editions, retitled The Necronomicon, still exist.
The book gives a description of the pre-human worship of the Old Ones, their banishment by the elder gods, and their imminent return. The revelations of cosmic horror contained within its pages are so intense that there is a 50% probability of characters below level 5 changing alignment to chaotic (1d6, 1-3) or going mad (4-6). This probability decreases by 5% for every level of the reader above 4th.
It would appear that spells are given for summoning all of the Old Ones and their minions, and some spells for their control and dismissal, although these latter are not always effective. The spells are very long and complicated, and not entirely comprehensible without long study and research. In fact, only users of magic of 18 intelligence have a chance of understanding (and thereby using) them, and that chance is only 5% per level, starting at the 6th level.
Many of the spells require that the “stars be right” and can only take place at certain times of the year or in certain places. Attempting to cast any of the greater summoning spells will result in a straight 30% chance of the caster going insane. The spells don’t always work: in particular they often fail to protect the user from the thing he or she has called from the outer darkness. Such unfortunates are rarely seen again, although simulacra or zombie-like imitations sometimes appear.
In addition to The Necronomicon, there are a number of other magical books giving information on the Old Ones and their minions, most of these are histories, but some have powers similar to, but lesser than, The Necronomicon itself. These lesser books are not as dangerous to the user or his surroundings.