Mother Hydra
Sandy Petersen's Cthulhu Mythos - Pathfinder

Mother Hydra

CR 14; XP 38,400
CE Elder deep one of evolution, fecundity, and mutation
Primary Source H. P. Lovecraft, “The Shadow Over Innsmouth”


Domains Chaos, Evil, Healing, Water
Subdomains Fear, Oceans, Restoration, Resurrection
Favored Weapon spear
Symbol feminine figurine partially wrapped in tentacles
Temple reefs, sea caves, underwater grottoes, waterfront churches
Worshipers deep ones, deep one hybrids, mutants
Servitors deep ones, sea monsters, shoggoths

Influence Stage 1 (DC 22)

Area 100-ft. radius spread; Nucleus 5 square feet
AC 29; Saves +17; hp 200
Proxy nucleus crystal
Effects enhance flesh, nucleus crystal
Escalation A worshiper of Mother Hydra who casts greater planar ally or gate within the area of influence escalates the influence to stage 2 by conjuring Mother Hydra.

Influence Stage 2 (DC 24)

CR 17; XP 102,400
Area 300-ft. radius
Proxy Mother Hydra
Effects enhance flesh, mobile influence


Combat Destroying the nucleus crystal ends this influence at stage 1. Killing Mother Hydra ends the influence at stage 2.

Influence Effects

Enhance Flesh All worshipers of Cthulhu, Father Dagon, or Mother Hydra within the area of influence gain fast healing 5, and gain a +2 bonus on all saving throws against effects that physically harm or debilitate the body. Affected creatures do not fall unconscious at negative hit points.

Nucleus Crystal At stage 1, attempts to damage Mother Hydra’s influence must be directed at the nucleus crystal at the center of the area’s influence. This influence’s effects function in a spread, so if the nucleus crystal is hidden inside a box, its influence radius is reduced to zero.

Mobile Influence Mother Hydra’s influence is always centered on her, allowing her to wander as she wills without being physically limited by the constraints of influence. Mother Hydra can teleport beyond the range of her influence.

Mother Hydra (CR 17)

XP 102,400
CE Huge aberration (aquatic, deep one)
Init +19; Senses see in darkness, tremorsense 60 ft.; Perception +31


AC 32, touch 23, flat-footed 17 (+15 Dex, +9 natural, –2 size)
hp 270 (20d8+180); fast healing 30
Fort +17, Ref +21, Will +20
Defensive Abilities freedom of movement; DR 10/epic and lawful; Immune ability damage, ability drain, aging, cold, death effects, disease, energy drain, mind-affecting effects, paralysis, petrification, poison; Resist acid 20, fire 20; SR 28


Speed 30 ft., swim 90 ft.
Melee +3 wounding shortspear +26/+21/+16 (2d6+13/19–20), bite +23 (1d8+5), claw +23 (1d6+5), tail slap +23 (2d6+5 plus stun)
Space 15 ft.; Reach 15 ft.

Spell-Like Abilities (CL 18th; concentration +25)
Constant—freedom of movement
At will—break enchantment, greater dispel magic, nightmare (DC 22)
3/day—demand (DC 25), quickened feeblemind (DC 22), baleful polymorph (DC 22)
1/day—implosion (DC 26)

Sorcerer Spells Known (CL 18th; concentration +25)
9th (3)—time stop
8th (5)—horrid wilting (DC 25), maze
7th (7)—greater teleport, insanity (DC 24), waves of exhaustion
6th (7)—chain lightning (DC 23), control water, flesh to stone (DC 23)
5th (7)—cone of cold (DC 22), dominate person (DC 22), hold monster (DC 22), wall of force
4th (7)—black tentacles, charm monster (DC 21), dimension door, phantasmal killer (DC 21)
3rd (8)—dispel magic, fly, lightning bolt (DC 20), slow (DC 20)
2nd (8)—acid arrow, alter self, blindness/deafness (DC 19), detect thoughts (DC 19), mirror image
1st (8)—grease (DC 18), mage armor, magic missile, ray of enfeeblement (DC 18), reduce person (DC 18)
0 (at will)—bleed (DC 17), dancing lights, detect magic, ghost sound (DC 17), mage hand, mending, message, read magic, touch of fatigue (DC 17)


Str 30, Dex 40, Con 28, Int 25, Wis 27, Cha 24
Base Atk +15; CMB +27; CMD 52 (can’t be tripped)
Feats Combat Casting, Eschew Materials, Extend Spell, Great Fortitude, Improved Critical (shortspear), Improved Initiative, Power Attack, Quicken Spell, Quicken Spell-Like Ability (feeblemind), Weapon Finesse
Skills Intimidate +30, Knowledge (arcana) +30, Knowledge (nature) +27, Knowledge (religion) +27, Perception +31, Sense Motive +28, Spellcraft +30, Stealth +30, Survival +31, Swim +41, Use Magic Device +27
Languages Aklo, Common, Deep One
SQ amphibious, mortal

Special Abilities

Mortal (Ex) Unlike most of the other entities associated with elder influences, Mother Hydra can be killed. If slain, though, it’s typically only a matter of time before an equally powerful deep one rises to fill the vacancy left behind by Mother Hydra.

Spells Mother Hydra casts spells as an 18th-level sorcerer.

Stun (Ex) A creature hit by Mother Hydra’s tail slap must make a successful DC 29 Fortitude save or be stunned for 1 round (or for 1d4 rounds if the attack was a successful critical hit). The save DC is Constitution-based.
Mother Hydra is an ancient and exceedingly powerful deep one in charge of their civic and biologistic activities. Deep ones undergo several changes as they grow in size and age. They are largely humanoid (at least they have four limbs and a head) until they reach over 1000 kg. At this stage, they can use magical and biological controls to direct their further growth. While some retain their regular proportions, others undergo dramatic metamorphoses. Mother Hydra helps guide this change and serves as a living example of what one can become. Her upper body still resembles that of a massive deep one female, but her hindquarters are more fish—or eel-like, giving her amazing speed compared to most deep ones, who must paddle along like frogs.

Cultural Import

Mother Hydra monitors the current status of the deep one species and, when necessary, personally directs the evolution of the deep ones so as to best secure their dominance. She decides how many deep ones are allowed to grow to greater size, and hand picks those who shall receive the honor. She also dictates which deep one communities are to seek contact with surfacedwellers for reproduction. If Father Dagon is killed (a rare occurrence), she picks his successor. In case of her own death, she has already chosen her own candidate, who can quickly replace her.

Mother Hydra has governed the creation of a number of hybrid monstrosities: combinations of deep ones with undersea horrors. She keeps some as guardians of the deep, and the rest are turned over to Father Dagon to join his military.

Mother Hydra in Combat

The mightiest of deep ones swims even faster than most of her ilk, striking with a massive spear strung with rotting kelp and withered flesh. She uses her powerful spells to achieve and demonstrate her superiority in battle.

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