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Great Old One

Source Bestiary 4 pg. 135
The Great Old Ones are otherworldly entities of almost unimaginable power—beings completely alien to humanity, both physiologically and spiritually. They exist in the forgotten corners of distant worlds or lost dimensions, yet their power is so great they can inf luence certain sensitive mortal minds in their dreams and nightmares, even if such inf luence is as accidental as a star’s gravitational pull on a tiny mote of dust adrift in space. In such ways, cults devoted to the Great Old Ones can rise on worlds throughout the Material Plane, even without prior contact between these worlds. Some of the Great Old Ones grant access to the domain of Void and its associated subdomains (see below).

While not all of the Great Old Ones are evil, all are forces of chaos. Their cults are almost always evil and cause harm and madness, but the Great Old Ones are generally content to ignore lesser life such as humans, elves, and dwarves. Yet when their attention is garnered, the results can be catastrophic on an immense scale— for just as the ant who bites someone’s toe invites swift destruction on a scale its feeble mind can’t envision, so too does humanity invite unimaginable ruin by delving into the affairs of these powerful creatures.

The Great Old Ones themselves often serve and worship even greater powers, such as Azathoth, Nyarlathotep, Shub-Niggurath, and Yog-Sothoth. Those creatures are the Outer Gods, and whereas the Great Old Ones can be thought of as akin to demigods, the Outer Gods are themselves true deities.

Other Great Old Ones

Bokrug, Cthulhu, and Hastur are but three of the Great Old Ones—countless others exist on distant worlds or other dimensions, yet are still able to influence the world through their dreams and cults. The central concept of the Great Old Ones was created by H. P. Lovecraft, one of the most influential writers of weird fiction—and horror fiction in general—of the 20th century. Lovecraft actively encouraged his writer friends to add to his mythos of creatures, and today we have Great Old Ones created not only by Lovecraft’s contemporaries like Clark Ashton Smith, Robert E. Howard, Henry Kuttner, and August Derleth, but also by modern writers like Ramsey Campbell, Brian Lumley, and Stephen King. Chaosium’s excellent Call of Cthulhu roleplaying game is a perfect place to start delving into the realm of Great Old Ones evoked in RPG form. By creating new Great Old Ones for your game, you can become part of a tradition of shared mythology nearly a century old!

Creatures in "Great Old One" Category

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Great Old One, Xhamen-Dor

A hideous tangle of hairlike fungal filaments writhes with nauseating purpose. Bones lie tangled in the wriggling mass, arrayed around a central draconic skull.

Xhamen-Dor CR 26

Source Pathfinder #113: What Grows Within pg. 86
XP 2,457,600
NE Gargantuan plant (aquatic, evil, Great Old One)
Init +24; Senses blindsight 60 ft., low-light vision; Perception +40
Aura unspeakable presence (300 ft., DC 31)


AC 44, touch 26, flat-footed 34 (+10 Dex, +10 insight, +18 natural, –4 size)
hp 602 (28d8+476); fast healing 20
Fort +33, Ref +21, Will +20
Defensive Abilities all-around vision, amorphous, immortality, insanity (DC 31); DR 15/epic and slashing; Immune ability damage, ability drain, aging, cold, death effects, disease, energy drain, mind-affecting effects, paralysis, petrification, plant traits, poison; Resist acid 30, fire 30; SR 37


Speed 40 ft., climb 40 ft., swim 60 ft.; air walk
Melee 4 tentacles +35 (3d6+18/19–20 plus grab), bite +35 (4d8+18/19–20 plus dread decay)
Space 20 ft., Reach 20 ft.
Special Attacks constrict (3d6+13), entangling shroud, infected dreams, mythic power (10/day, surge +1d12)
Spell-Like Abilities (CL 26th; concentration +33)
Constant—air walk, greater magic fang
At will—animate deadM, control undead (DC 24), dimension doorM, dreamM, greater dispel magic, nightmareM (DC 22), wall of thornsM
3/day—control plants (DC 25), create greater undead, create undead, demand (DC 25), quickened feeblemind (DC 22), quickened wither limb (DC 23)
1/day—cursed earth, microcosm (DC 26), symbol of insanity (DC 25)


Str 36, Dex 30, Con 45, Int 19, Wis 28, Cha 25
Base Atk +21; CMB +38; CMD 68
Feats Combat Reflexes, Critical Focus, Greater Vital Strike, Improved Critical (tentacle), Improved Critical (bite), Improved Initiative, Improved Vital Strike, Iron Will, Lightning Reflexes, Power Attack, Quicken Spell-Like Ability (feeblemind, wither limb), Staggering Critical, Vital Strike
Skills Climb +21, Knowledge (arcana) +18, Knowledge (geography) +18, Knowledge (nature) +32, Knowledge (religion) +32, Perception +40, Spellcraft +32, Swim +52
Languages Aklo; telepathy 100 ft.
SQ amphibious, compression, contagious lore, no breath, powerful tentacles


Environment any
Organization solitary (unique)
Treasure triple

Special Abilities

Contagious Lore (Su) Any creature that learns Xhamen-Dor’s name and comprehends the Great Old One’s nature as an insidious parasite (this typically requires a creature to be exposed to information in a book or to be taught the information, but also automatically affects any creature who succeeds at a Knowledge check to learn more about the Great Old One) is at risk of being targeted by Xhamen-Dor’s infectious dreams. Every year, there is a flat 1% chance that such a creature can be targeted by the Great Old One’s infected dream ability. If 5 years pass without being targeted, the victim “forgets” about Xhamen-Dor until taught of the Great Old One again. A miracle or wish can spell also cause someone to forget in this way.

Dread Decay (Su) A creature damaged by Xhamen- Dor’s bite becomes afflicted by a fast-acting infection that swiftly rots flesh and bone into a foul-smelling gangrenous slop. The bitten creature must succeed at a DC 41 Fortitude saving throw or take 2d6 points of Strength drain and 2d6 points of Constitution drain. On a successful save, the victim takes only 2 points of Strength drain and 2 points of Constitution drain. A creature whose Strength score is reduced to 0 by this effect falls comatose and immediately experiences infected dreams (see below). A creature whose Constitution score is reduced to 0 by this effect is immediately absorbed into Xhamen-Dor’s body, along with its memories, mind, and soul. Such a creature cannot be restored to life except via wish or miracle. Even then a creature brought back to life in this manner experiences infected dreams (see page 87). This is a disease effect. The save DC is Constitution-based.

Entangling Shroud (Su) Xhamen-Dor is surrounded by a writhing storm of fungal filaments that fills an area equal to his reach. While these filaments are almost microscopic in width, they are quite strong and capable of swatting aside ranged weapon attacks, granting Xhamen-Dor a 50% miss chance against all such attacks. In addition, any creature that ends its turn within Xhamen-Dor’s reach must succeed at a DC 37 Reflex saving throw or become entangled as long as it remains in that area. An entangled creature can try to break free as a move action; the DC of the Strength or Escape Artist check is equal to that of the Reflex save to avoid becoming entangled in the first place. The save DC is Strength-based.

Great Old One Traits Rules for Xhamen-Dor’s Great Old One traits like immortality, insanity, its mythic abilities, otherworldly insight, and the base rules for unspeakable presence can be found on page 306 of Pathfinder RPG Bestiary 4.

Immortality (Ex) If Xhamen-Dor is slain, its body collapses into a reeking pile of fungus, hair, and bones. The core of its being compresses down to a tiny blot of incorporeal fungal matter that is immediately expelled from the core of its mass and hurled out into the depths of space. All creatures within 120 feet of Xhamen-Dor when this occurs must succeed at a DC 31 Fortitude saving throw or take 2d6 points of Charisma drain as portions of their sanity and souls are pulled along with the blot. Xhamen-Dor’s remains animate as a unique undead creature known as a seeded 24 hours after this event (see page 90 for statistics), but this is merely an echo of the Great Old One. Xhamen-Dor is reborn again when one of two events occur: the blot fired into space impacts a planet, or one of its surviving seeded returns to Carcosa and resurrects as the Great Old One. If the former, it can be centuries or even eons before Xhamen-Dor awakens again, but if the latter, the Great Old One can return within a matter of months or less. The save DC is Charisma-based.

Infected Dreams (Su) Any knowledgeable creature that has succumbed to the yearly 1% chance of Xhamen-Dor’s contagious lore ability (see page 86) or whose Strength score has been drained to 0 by dread decay (see page 86) can be targeted by the Great Old One’s nightmare spell-like ability, regardless of the distance between the creature and Xhamen-Dor. In order to use infected dreams against a target, Xhamen-Dor must successfully affect that target with its nightmare spell-like ability. If the victim fails its saving throw against the nightmare, it becomes infected with the following virulent fungal blight.

Seeded Infestationsave Fort DC 41; onset immediate; frequency 1/day; effect 1d4 Con drain; cure none. This infestation can be cured only by magic. A creature whose Constitution score is reduced to 0 by this infestation dies and rises in 1d4 rounds as a seeded creature (see page 90). This is an infestation effect. The save DC is Constitution-based.

Powerful Tentacles (Su) Xhamen-Dor’s tentacles are treated as primary natural attacks.

Unspeakable Presence (Su) Failing a DC 31 Will saving throw against Xhamen-Dor’s unspeakable presence causes a victim to become nauseated for 1d4 rounds, and then sickened for an additional 2d4 rounds. The save DC is Charisma-based.


Spawned countless eons ago within the deepest tainted reservoirs hidden in the foul sewers of Carcosa, the fungal infestation known as Xhamen-Dor, the Inmost Blot, has traveled from world to world for ages untold, infesting reality and returning time and time again to its place of creation to expand the alien city’s scope. Full details on this destructive agency of parasitism can be found on pages 62–67.

Xhamen-Dor is an elephantine mass of fungus and hairlike tendrils capable of assuming any basic form, although its preferred shapes are that of a serpentine creature, a spiderweb-like tangle, or a shuddering carpet of filth.

Xhamen-Dor’s Cult

Xhamen-Dor’s cult is unusual in that once it becomes active, it spreads slowly until it reaches a tipping point. Then, its seeded minions quickly overtake entire populations. In most worlds where it is worshiped, its cult is small in number and isolated. Xhamen-Dor’s places of worship are found in sewers, graveyards, and other shunned places within civilized realms, but in ruined cities they can expand to encompass multiple buildings. Xhamen-Dor grants access to the domains of Death, Evil, Plant, and Trickery and to the subdomains of Decay, Deception, Murder, and Undead. Its favored weapon is the spear.