Monstrous Physique: Boiúna

Greetings! I’m Luis Loza, freelance writer and game designer, and I wish to welcome you to the first installment of Monstrous Physique. My silly writer brain is always growing new monsters and the kind folks at the Know Direction network have given me permission to release these beasts in to their protective custody. I will be crafting new creatures every other week and unleashing them for your game table to enjoy.

The aim of this series is to not only bring a new creature to life, but also provide an understanding as to how the final creature came to be. I’ll discuss the sources that inspired the creature and the reasons for its design decisions. I will also be providing a few hooks for you to add these creatures into your game. Without further ado, let’s take a look at our first creature, the boiúna!


Deep onyx scales cover the thick musculature of this enormous snake. Its eyes glow a pale white as an aggressive hiss escapes its maw.

Boiúna                           CR 14
XP 38,400
N Colossal magical beast (aquatic)
Init +7; Senses darkvision 60 ft., low-light vision, scent; Perception +27
AC 25, touch 5, flat-footed 22 (+3 Dex, +20 natural, –8 size)
hp 210 (20d10+110)
Fort +19, Ref +19, Will +12
Defensive Abilities jungle’s protection; DR 5/—; Resist acid 5, fire 5, cold 5, electricity 5; SR 25
Speed 60 ft., climb 60 ft., swim 100 ft.
Melee bite +22 (6d8+13 plus grab/19–20)
Space 50 ft.; Reach 50 ft.
Special Attacks capsize, constrict (6d8+13), swallow whole (6d8+18 bludgeoning, AC 20, 21 hp)
Str 38, Dex 17, Con 20, Int 18, Wis 19, Cha 21
Base Atk +20; CMB +37 (+41 bull rush and grapple); CMD 50 (+52 vs. bull rush, can’t be tripped)
Feats Awesome Blow, Combat Reflexes, Greater Bull Rush, Improved Bull Rush, Improved Initiative, Improved Critical (bite), Lightning Reflexes, Power Attack, Skill Focus (Stealth), Weapon Focus (bite)
Skills Climb +40, Diplomacy +25, Knowledge (nature) +24, Perception +27, Stealth +16, Swim +40,
Languages Common; speak with animals, telepathy 100 ft.
SQ amphibious, extraordinary camouflage
Environment tropical jungles
Organization solitary
Treasure none
Capsize (Ex) A boiúna can attempt to capsize a boat or ship of its size or smaller by ramming it as a charge attack and making a combat maneuver check. The DC of this check is 25 or the result of the boat captain’s Profession (sailor) check, whichever is higher.
Extraordinary Camouflage (Su) A boiúna has the ability to remain unseen within a jungle and is even capable of disguising itself as common jungle fixtures. If a boiúna remains still for at least one round, it becomes untraceable as per invisibility. See invisibility and similar effects can discern the boiúna while it remains still.
As a full-round action, a boiúna takes the form of an enormous tree, a giant area of brush, an empty boat, or other, large mundane object. This functions as polymorph any object, save that the boiúna may revert to its normal form as a full-round action. While transformed in this way, the boiúna does not benefit from the untraceable portion of this ability. Creatures that attempt to locate the boiúna with scrying, true seeing, or similar effects must succeed on a DC 25 Will save or believe the boiúna is the mundane fixture it is disguised as. This save DC is Constitution-based.
Jungle’s Protection (Su) A boiúna is intrinsically linked to the jungle it watches. This protection is reciprocated by the spirit of the jungle itself. A boiúna gains a bonus equal to half its Charisma bonus (minimum 0) on all saving throws. As an immediate action, a boiúna can transfer this bonus to a creature within 30 feet until the end of the boiúna’s next turn.

Boiúnas are the eternal guardians of a jungle. Each jungle hides one of these titanic serpents, said to be born at the same time as the jungle itself. When strangers enter its domain, a boiúna follows the creatures to learn of its intentions. Any intruders that would bring harm to the jungle are brought to an end. Boiúnas will sometimes test visitors by disguising themselves as sunken ships or destroyed caravans loaded with treasures. Those whose hearts are filled with greed find a swift end in the hands of the boiúna. If it is ever destroyed, a boiúna is reborn in the heart of its jungle. It begins life anew as a simple snake that flourishes to its gigantic size in a few weeks.

In Your Game

The Stolen Heart
A recent expedition into the nearby jungles returns with what they refer to as the Heart of the Jungle. This massive blood ruby is an ancient artifact that wards the jungle, keeping its cursed spirits in check. The jungle’s defender, an ancient boiúna sets out into the PCs city to reclaim the gem before the spirits awaken to haunt the lands.

A New Jungle
Strange images haunt the dreams of the PCs. These visions guide the PCs to small grove that hides a large egg, ready to hatch into a new boiúna. It is up to the PCs to guard the newborn from poachers as well as assist the snake in the formation of its new jungle.

The Stranded Serpent
Fey trickery lead to the displacement of a boiúa into an infinitely sprawling jungle in a pocket plane. The boiúna’s original jungle home is in peril as its spiritual link to the serpent defender is severed, withering the forest at an extreme rate. It is up to the PCs to traverse the dangerous jungle and locate the missing boiúna to return it home.

Monstrous Origins

Pathfinder monsters have their origins in a number of sources: folklore, mythology, books, video games, and so on. I wanted to draw from the well of folklore monsters that is so common throughout the bestiaries. In my search I found the boiúna, a creature from Brazilian mythology. It is said that that a river’s channel is created from the slithering of the boiúna through the rain forest. Also, according to legend, the boiúna is capable of disguising itself as different types of boat and even a woman. With this in mind, I decided that the boiúna would be a perfect guardian of the jungle.

With all this in mind, I got to work. There are already a large number of snakes in the bestiaries,  the biggest of which rests at CR 10. I wanted to craft the boiúna as the ultimate snake. However, the sea serpent already exists at CR 12. I decided to go a step above and shoot for CR 14. The boiúna is meant to be a bit mean with its stats, especially its grab. To make up for this, I toned down its AC just a tad. Additionally, I didn’t provide it with a ranged attack, so it would be difficult for the boiúna to deal with the flight and other abilities that higher level PCs have access to. Finally, I wanted to use the shape shifting ability in some capacity, but not in the same vein as the legend. To this end, the camouflage ability was born, allowing the boiúna to be the silent defender it needs to be.

Well, that’s it for this entry! Please let me know what you think. If you end up using the boiúna 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 Lost Omens 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 his cat, and walks with his wife. He is eternally plagued with a hunger for tacos. Consider checking his material on his Patreon at


  1. Woooooooo!

    Can I make a request here?

    Can I request intelligent zombie dinosaurs?

  2. Christopher Eich

    I like the segment, but isn’t Friday normally Iconic Design day? Where’s Alex?

    • Alex Augunas

      Iconic Design is going biweekly in order to make room for Monstrous Physique.

      • Christopher Eich

        Awwww. Iconid Design is by far my favorite segment.

        • Christopher Eich

          Iconic. I can totally spell English words….

        • Alex Augunas

          I like writing Iconic Design! But its also the second work-heavy thing I do for the KDN (after Private Sanctuary). And my workload was getting to the point where it was difficult to balance my KDN duties, my day job, and my work for EMG/RGG.

          I actually asked Ryan and Perram if we could bring Luis aboard after we had him on the show, and offered my Friday slot to him to try and balance my workload a bit better. As it stands, I’m currently the only blogger on the site who has a weekly segment (Guidance is still every Monday), so making even this small cut will help me out tremendously.

  3. Will


    Are you still in Lincoln, Nebraska? I’m trying to get PFS here in Lincoln off the ground and could always use more players!