Tsathoggua, Father Of Formless Spawn
Sandy Petersen's Cthulhu Mythos - Pathfinder

Tsathoggua, Father Of Formless Spawn

CR 18; XP 153,600
CE Great Old One of magic, outcasts, and the underworld
Primary Source Clark Ashton Smith, “The Tale of Satampra Zeiros”


Domains Chaos, Evil, Knowledge, Magic
Subdomains Arcane, Divine, Thought, Whimsy
Favored Weapon short sword
Symbol crouching eyeless toad
Temple caverns, mountain valleys, ruined cities, stone cathedrals
Worshipers deranged wizards, philosophers, and scholars, dwellers of the underworld
Servitors formless spawn

Influence (DC 26)

Area 1-mile radius
Proxy avatar of Tsathoggua
Effects bolster formless spawn, enhance magic


Combat Tsathoggua can be defeated via combat, but can also be placated via sacrifice or overfeeding (see the stats for his avatar below). If placated in this way, his avatar does not vanish, but his influence becomes suppressed until he is wakened once more.

Influence Effects

Bolster Formless Spawn Tsathoggua bolsters all formless spawn within his influence, which gain a +5 profane bonus to their Armor class, attack rolls, and saving throws, and +5 additional hit points per Hit Die (+50 hp for the typical formless spawn). Any creature damaged by a formless spawn that has been bolstered by this aura must make a Fortitude save (against the influence’s effect) or become staggered for 1 round by the brutality of the attack (the stagger durations of multiple hits do not stack). A formless spawn bolstered in this way is a CR 12 creature.

Enhance Magic The save DCs of all spells and spell-like abilities cast by worshipers or allies of Tsathoggua (including those created by Tsathoggua himself) are increased by +2, and checks made by these spellcasters to overcome spell resistance gain a +4 profane bonus.

Avatar of Tsathoggua (CR 18)

XP 153,600
CE Huge aberration
Init +7; Senses see in darkness, true seeing; Perception +31


AC 33, touch 15, flat-footed 26 (+7 Dex, +18 natural, –2 size)
hp 310 (20d8+220); fast healing 15
Fort +17, Ref +15, Will +20
Defensive Abilities amorphous, freedom of movement, formless blood; DR 15/epic and lawful; Immune ability damage, ability drain, acid, aging, death effects, disease, energy drain, mind-affecting effects, paralysis, petrification, poison; Resist cold 30, electricity 30; SR 29
Weaknesses lassitude, sacrifice


Speed 30 ft., climb 30 ft.
Melee 4 claws +26 (3d6+13/19–20 plus grab)
Space 15 ft.; Reach 15 ft.
Special Attacks command spawn, devour

Spell-Like Abilities (CL 20th; concentration +28)
Constant—freedom of movement, true seeing
At will—greater dispel magic, nightmare (DC 25)
3/day—gate (for travel only), black tentacles, demand (DC 28), quickened feeblemind (DC 25)
1/day—miracle, symbol of insanity (DC 28)

Sorcerer Spells Known (CL 18th; concentration +26)
9th (3)—time stop
8th (6)—horrid wilting (DC 28), power word stun
7th (7)—control undead (DC 27), finger of death (DC 27), insanity (DC 27)
6th (7)—acid fog, disintegrate (DC 26), mass suggestion (DC 26)
5th (7)—baleful polymorph (DC 25), dominate person (DC 25), telekinesis, wall of force
4th (8)—confusion (DC 24), dimension door, enervation, phantasmal killer (DC 24)
3rd (8)—fly, haste, major image (DC 23), stinking cloud (DC 23)
2nd (8)—blindness/deafness (DC 22), command undead (DC 22), darkness, detect thoughts (DC 22), mirror image
1st (8)—grease (DC 21), mage armor, magic missile, ray of enfeeblement (DC 21), shield
0 (at will)—arcane mark, bleed (DC 20), dancing lights, detect magic, ghost sound (DC 20), mage hand, message, prestidigitation, touch of fatigue (DC 20)


Str 36, Dex 25, Con 32, Int 29, Wis 26, Cha 27
Base Atk +15; CMB +30; CMD 47 (can’t be tripped)
Feats Arcane Strike, Combat Casting, Critical Focus, Eschew Materials, Improved Critical (claws), Lightning Reflexes, Maximize Spell, Quicken Spell, Quicken Spell-Like Ability (feeblemind), Staggering Critical
Skills Climb +21, Intimidate +31, Knowledge (arcana) +32, Knowledge (dungeoneering) +29, Knowledge (engineering) +29, Knowledge (history) +29, Knowledge (nature) +29, Knowledge (planes) +29, Knowledge (religion) +29, Perception +31, Sense Motive +28, Spellcraft +32, Stealth +22, Use Magic Device +28
Languages Aklo, Common, Undercommon; telepathy 100 ft.

Special Abilities

Command Spawn (Su) Tsathoggua can direct the actions of all formless spawn within sight via telepathy at will, at any time during a combat round without taking an action.

Devour (Su) Once per round as a free action, Tsathoggua may transfer a creature he has grappled in that round to his devouring maw. This inflicts 8d6 points of damage to the victim, who must also make a successful DC 31 Fortitude save or suffer 2 points of ability drain to each ability score. Whenever Tsathoggua drains any ability scores in this way, he heals 30 hit points and gains the benefits of a restoration spell. The save DC is Constitution-based.

Formless Blood (Su) Whenever Tsathoggua takes piercing or slashing damage, his blood pours out and creates a formless spawn.

Lassitude (Ex) When Tsathoggua feeds on a creature via his devour ability, there’s a 5% chance that he grows sleepy and falls into a torpor. When this occurs, he is immediately healed of all hit point damage and cured of all detrimental effects, but is treated as unconscious. He immediately awakens if he takes any damage or is otherwise harmed.

Sacrifice (Ex) When a non-worshiper of Tsathoggua sacrifices a willing or helpless living creature with an Intelligence score of at least 3 by offering the sacrifice to Tsathoggua for him to devour, the chance of him being affected by his lassitude rises to 50%. Sacrificing a creature in this way, even if it is a willing creature, is a chaotic evil act and may have alignment repercussions. If Tsathoggua does not become affected by his lassitude as a result of this sacrifice, he becomes enraged and cannot be affected by lassitude for 24 hours.

Spells Tsathoggua casts spells as an 18th-level sorcerer. Once per day, by concentrating for 1 hour, he may completely change what sorcerer spells he knows—the spells given in his statistics above represent his typical spells known. The save DCs for his spells gain a +2 bonus from his influence (see above); this bonus is already calculated into his stats above.

Tsathoggua has been called a primitive god, a sort of hybrid bat/toad, as well as an endlessly changing black fluid like his formless spawn. The truth is that Tsathoggua is all of these. His outer form—the shell he presents to mortals—is the well-known repulsive hybrid of bat, toad, and sloth, and this is how he is portrayed in his iconography. But this is a sort of cocoon, a container that protects and contains his true form, which is that of a monstrous fluid. Tsathoggua can project his fluids from this shell, creating formless spawn from himself. Perhaps he is simply a construct the formless spawn have built to house their magical and spiritual potential, or perhaps he is the final stage of their life-cycle and evolution. In any case, they are he and he is they.

The formless spawn work toward their own individual goals, and are not formally organized, but their instincts and desires spread Tsathoggua’s influence and ability to feast, so there is a kind of unnatural unity of effect in their actions. Tsathoggua’s temples often host a formless spawn as a representative of the god, and sacrifices are made to it.

Sleeper in Darkness

Tsathoggua normally dwells deep underground, but can be called forth either in person or in vision. He also is sometimes made manifest in his temples. More than most Great Old Ones, he rejoices in an effective cult structure.

Tsathoggua is famously lethargic and difficult to awaken, but he is also well known for his hunger and interest in sacrifice. Beings offered to him as prey are grasped in his claws and pulled to his mouth, where the black formless fluid engulfs them and sucks out all fluids from quickly desiccated corpses.

Followers of Tsathoggua

Tsathoggua is particularly adept at magical effects, and can appear in visions to his priests. He is desirous of worship, and will actively assist important priests and wizards in his cult. He can open magic gates to many areas in the universe, teach unique spells, and bring about dark miracles in return for service to him. Service to Tsathoggua always includes the sacrifice of victims, typically sentient. Tsathoggua receives these sacrifices in person, which his worshipers claim technically absolves them of each murder.

Tsathoggua in Combat

In battle, Tsathoggua can project formless spawn from his mouth or other orifices to defend him even as he grasps victims with his claws and pulls them in to feed upon. His feeding is a horrifically painful process, involving acid corrosion and destruction of tissue. He is difficult to harm, with his tough exterior shell and lack of internal vitals. In addition, when he is wounded, he bleeds ever more formless spawn, giving him an advantage in long battles.

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