Monstrous Physique — Yig, Father of Serpents

The stars are almost right for the release of the Strange Aeons Adventure Path. Each issue will contain a Great Old One to be unleashed upon unfortunate players and I found myself wanting to take a crack at such a mean beastie. Great Old Ones are nothing to sneeze at and I think my take on Yig, the Father of Serpents, is a doozy.


This enormous man bears thick, horrendous scales and yellowed slit eyes. His face is elongated and an unbearable rattle emanates all around him.

Great Old One, Yig         CR 26
XP 2,457,600
CN Huge monstrous humanoid (aquatic, chaotic, Great Old One, shapechanger)
Init +13; Senses blindsense 60 ft., darkvision 120 ft., low-light vision, scent, serpent sight, true seeing; Perception +46
Aura unspeakable presence (300 ft., DC 33)
AC 41, touch 32, flat-footed 27 (+10 deflection, +13 Dex, +1 dodge, +9 natural, –2 size)
hp 525 (30d10+360); regeneration 20 (epic and fire)
Fort +22, Ref +30, Will +26
Defensive Abilities immortality, insanity (DC 33); DR 15/epic and lawful; Immune ability damage, ability drain, aging, cold, death effects, disease, energy drain, mind-affecting effects, paralysis, petrification, and poison; Resist acid 20, electricity 20; SR 37
Speed 50 ft., burrow 40 ft., climb 60 ft., swim 60 ft., air walk
Melee bite +37 (6d10+9 plus grab and poison), 2 slams +37 (4d8+9),
Ranged venomous spit +43 (4d10 acid plus poison)
Space 15 ft.; Reach 15 ft. (20 ft. with bite)
Special Attacks call of the Serpent Father, constrict (6d10+9), mythic power (10/day, surge +1d12), serpent’s curse
Spell-Like Abilities (CL 26th; concentration +33)
Constant—air walk, true seeing
At will—acid arrow, dreamM, dimension doorM, charm animal (DC 19), charm person (DC 19), commandM (DC 19), nightmareM (DC 23), overwhelming poison, poison (DC 22)
3/day—charm monster (DC 22), demand (DC 26), dominate animal (DC 21), dominate person (DC 22), greater teleport, sepia snake sigil (DC 21), snake staff (DC 23), suggestionM (DC 21), sundered serpent coil
1/day—dominate monster (DC 27), geas (DC 24), plane shift (DC 25)
Str 28, Dex 36, Con 35, Int 31, Wis 28, Cha 27
Base Atk +30; CMB +44; CMD 68 (cannot be tripped)
Feats Acrobatic Steps, Alertness, Athletic, Blind-Fight, Combat Expertise, Combat Reflexes, Deceitful, Dodge, Mobility, Nimble Moves, Persuasive, Power Attack, Spring Attack, Stand Still, Stealthy
Skills Bluff +42, Climb +19, Diplomacy +42, Disguise +42, Escape Artist +47, Intimidate +45, Knowledge (history) +40, Knowledge (nature) +40, Perception +46, Sense Motive +43, Stealth +42, Survival +42, Swim +19
Languages Aklo, Cyclops, Draconic, Druidic, Giant, Undercommon; speak with animals (all snakes), telepathy 200 ft.
SQ amphibious, change shape (any snake, polymorph), compression
Environment Any
Organization solitary (unique)
Treasure triple
Call of the Serpent Father (Ex) Once per week, Yig may call to his children to do his bidding. As a full-round action, Yig calls all snakes with 5 HD or fewer within a 1 mile radius. These snakes arrive within 1 hour of the call. Additionally, 2d4 purple worms or 2d4 sea serpents arrive within 1d6 rounds of this call. All creatures called in this manner follow Yig’s orders unquestionably for up to 24 hours, after which they return to their homes.
Immortality (Ex) If Yig is killed, his body immediately begins to convulse and spray poisonous acid, continuing to do so for 1d4 rounds. This acid deals damage as Yig’s venomous spit in a 60 foot area around Yig’s body. At the end of this time, his scales molt and instantly transform into thousands of small snakes. These snakes flee in every direction, even burrowing through the ground to escape. The snakes remain hidden for centuries, eventually reuniting to recreate Yig’s form.
Any effect that destroys Yig’s body (such as disintegrate) merely causes him to instantly molt as described above, but such measures prevent his body from convulsing prior to this molting.
Poison (Ex) Bite or venomous spit—injury; save Fort DC 37; frequency 1/round for 10 rounds; effect 2d4 Con and 1d6 Str; cure 2 saves. A creature cannot be killed by this poison, even if the ability damage would equal or exceed its current Constitution or Strength scores. Instead, that creature becomes an unthinking being that strictly follows Yig’s command. The creature can only be liberated of this mental enslavement via a miracle or wish cast by a mythic creature.
Rattle (Ex) A constant, mind-altering rattling surrounds Yig. This rattle can be heard up to 500 feet away. Any creature exposed to the sound of the rattling must succeed a DC 33 Will save or become compelled to approach the source of the sound. Creatures within 90 feet of the rattle must succeed on a second save or become fascinated for 2d6 rounds. Creatures fascinated receive a –4 penalty to save against any effects create by Yig. Offensive actions from Yig do not break this fascination. Yig may silence this rattling as a free action. Deaf creatures or creatures withing areas of silence or similar effects are still able to perceive the rattling, but receive a +8 bonus to save against this effect. The save DC is Charisma-based.
Serpent’s Curse (Ex) As a full-round action, Yig may curse a creature to transform into a snake. The creature must succeed on a DC 33 Will save or succumb to the curse, gaining snake-like features. The creature immediately receives 2 Charisma, Intelligence, and Wisdom drain. Every week, the creature must succeed on another DC 33 Will save or receive an additional 2 ability drain to the same scores and slip further into the appearance of a snake. When one of these ability scores is reduced to 0, the cursed creature instantly becomes a snake under Yig’s control. This snake form is immune to aging. The curse and its ability drain can only be alleviated by a mythic creature. The save DC is Charisma-based.
Serpent Sight (Ex) By concentrating, Yig can share the senses of any snake or serpentfolk within 1 mile of him, allowing him to see, smell, and hear as if he were that creature. These creatures are unaware of Yig’s presence or that they share their senses with him during this time.  While he is sharing senses, Yig is still aware of his surroundings, but receives a –8 penalty to any Perception checks.
Unspeakable Presence (Su) Failing a DC 33 Will save against Yig’s unspeakable presence afflicts a  creature with a random insanity. A creature that is already insane instead becomes confused for as long as it remains in the area. The save DC is Charisma-based.

According to legends, Yig is arrived to the world and brought his children the serpents along with him. His children were sent out to the world to find the most locate the most important creatures. Humans were the first to be found. Yig made himself known to the humans and offered them many gifts. Soon, some humans turned their back to Yig, but there were always humans who praised their Serpent Father. Yig chose to remain away from humanity’s focus, content to let his children watch the humans. Instead, Yig simply asked those that remained loyal to him to continue to serve him and they would be rewarded. These humans are said to have eventually become the serpentfolk, tasked with reclaiming the world for Yig.
Today, Yig waits patiently to take the world for himself. He continues to be a subtle manipulator, placing machinations into effect with results that take centuries to manifest. Yig is quick to jump at the opportunity to lure another person to his cult, as he revels in the act of seducing creatures. In the short term, he offers his blessings and protections to tribes of people willing to listen the hisses of his children. With proper offerings, these tribes find prosperity. Those who refuse him, find only anguish and Yig’s wrath. Until his machinations transpire, Yig remains hidden deep in a labyrinthine cavern in the heart of the thickest, remote jungle of the world.

In Your Game

The Viper Traitor
Yig has gone back on his word to the PCs. The PCs are left stranded in a serpentfolk city with only the shirts on their backs after an agreement with cultists of Yig goes wrong. The PCs must return home and put an end to the cult while contending with the endless snake people attempting to put an end to them once and for all.

The Great Migration
A mass movement of serpents of all kinds and sizes draws the PCs to a bottomless pit deep in the Winding Canyon. Here, the serpents surround the pit and wait for the PCs to enter and further their Father’s goals.

Defenders of the Serpent’s Will
The PC’s village always follows the Serpent Father’s wishes and receives his blessing in return. A group of outsiders arrives in the village and threatens to destroy Yig’s followers. It is up to the PCs to defeat the blasphemers, root out their home, and raze that place to keep the village safe.

Monstrous Origins

As mentioned in the introduction, the fact that there would be six Great Old Ones statted up in the upcoming adventure volumes sparked the desire to make my own. (We shall see in a few months if I didn’t double up with Paizo!) I searched through the different Great Old Ones available and settled on Yig. He seemed the Great Old One most likely to interact with humanity directly and to that end, I provided him with many enchantment abilities to cater to that cause. Creating a very high CR creature can prove challenging in regards to finding enough abilities to keep the creature interesting. There was a lot of back and forth between making the abilities too simple and too outlandish. I think I found the perfect medium point to keep Yig threatening but not absolutely unstoppable.

In this incarnation, Yig is meant to be more of a background figure either for a short adventure or even an extensive campaign. He works best when he is out of sight, but his actions are not. Cultists, serpentfolk, and other followers should be the PCs main antagonists and Yig, if he is ever seen, will be the climactic end to many months or years of arduous antagonizing. If all goes well, Yig’s name will be cursed and the PCs will never have seen him at all.

That’s it for this week! Please let me know what you think. I’m especially interested to hear if people would prefer more high level or low level challenges. If you end up using Yig, or even just his cultists, in your game or you have any request for a future Monstrous Physique, please drop me a line at

Luis Loza

Luis Loza is a developer at Paizo, working on the Pathfinder World Guide line and formerly on Campaign Setting and Player Companion lines. He's done freelance for Paizo Inc, Legendary Games, Rogue Genius Games, and more third-party publishers. His hobbies include gaming both tabletop and video, making jokes, obsessing over time travel, taking naps with Nova the cat, and walks with heather the wife. He is eternally plagued with a hunger for tacos.

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