Minimum Viable Population

The Truth

Each year, the Florida Fish & Wildlife Conservation Commission holds a hunting contest to cull invasive Burmese pythons from the Everglades. One decade later, this practice has attracted the mercurial rage of Yygg, the Father of Serpents. With each snake-kin exterminated, his influence grows. Neil Greenwood, the FWC commissioner, was plagued with nightmarish visions of writhing masses and teeth until one night, desperate to bring things back to the way they were, Greenwood took it upon himself to confront Yygg alone. Inexperience proved to be his undoing. Greenwood’s corpse lays dormant in his pool as the Father of Serpents gathers enough strength to manifest into it and carry out his retribution.


The Agents are urgently summoned to an NSA office in Miami (an office that none of them even knew existed) for a high priority 11: 00AM meeting with Agent Lacerda. Upon their arrival, the agents are escorted by armed guards to the center of the building. Lacerda sits in a windowless cuboid office, illuminated only partially by a dim lamp and fairy lights. In one corner stands a filing cabinet and a portable stereo playing new-age music. There are no chairs. Lacerda dismisses the guards and greets the agents by their government names. This is a power move.

Lacerda’s briefing is snappy: the Agents are to check in on FWC South Regional Commissioner Niel Greenwood. Lacerda had flagged Greenwood as a potential UIP (Lacerda declines to elaborate on the acronym) after a string of out-of-character work absences and a series of alarming keywords showing up in his online activity. The agents are to follow up with a wellness check. If he’s about to do something rash, then talk him down from it. A dossier containing Greenwood’s address is given to the agents, as well as an enhanced photocopy of his house keys that can be cloned with a Craft: Locksmith check, or a trip to the hardware store.

Since this should just be a quick and easy visit, no additional resources, cover, or personnel were allocated to this operation.

The Commissioner’s Residence

Greenwood’s home is a one-story ranch house in a sleepy suburb outside Miami. The front yard is abuzz with activity, with swaying plants and local wildflowers attended to by bees and hummingbirds. A green 1996 F-150 is parked in the driveway. The curtains are all drawn, and it appears warmly lit inside. All exterior windows and doors are latched and locked. A cedar privacy fence encloses the entire backyard—it is further reinforced by an outwards-facing electrified razor wire overhang to prevent wildlife from climbing over. It takes a passed Athletics roll and material to cover the wire to maneuver over with failure taking 1d4 damage.

It is past noon. Kids are at school, and the streets are quiet. The suburb is tightly guarded against criminal behavior—indicated by several neighborhood crime watch signs. Alertness / Search shows that most of the paranoid little houses are protected by security systems and doorbell cameras. Any foul play will result in a police response in 3+1d10 minutes.

No one comes to the door, so the Agents will have to let themselves in.


The cozy house is the picture of vintage chic. It has changed little since the 1970s. It is floored throughout with beige berber carpeting and wood, and the walls are paneled with oak. Tasteful nature photographs are framed along the walls. A variety of critters live in enclosures throughout the home—it appears that Commissioner Greenwood had decided to bring his work home with him. An African grey parrot in a large cage in the living room sits on a branch and screams at the agents as they approach. A sign reading “Linnaeus's Castle” hangs from the bars. A large saltwater tank containing tropical fish and one eel separates the kitchen from the dining room. The tank emits a low hum. In the dining room, the table has been forcefully pushed against the wall. A circular sigil is painted on the floor in ink, surrounded by 32 still-burning candles that smell faintly of sage. Dark, oxidized, organic material is smeared in a trail along the floor, leading from the ritual site and through the shattered glass sliding doors. A Medicine check determines that the dark material is necrotic human tissue. Cytotoxins are heavily present throughout the sample. The study next to the living room contains a desktop computer. CompSci≤30 grants the agents administrative access. Greenwood’s search history shows extensive research into Mesoamerican gods, Oklahoma folklore, and occult warding rituals (largely centered around serpents and reptiles). A metal shelf behind the desk holds four glass tanks containing one day gecko, one boomslang, one tarantula, and one angry-looking Pacman frog. Greenwood’s bedroom is disorderly. He left dirty laundry in three heaping mounds across the floor, and his bedsheets were thrown aside in a hurry. There is a glass terrarium containing a neat colony of rasberry crazy ants on his bedside table. The master bathroom medicine cabinet contains anti-anxiety medications, melatonin, and four antivenom vials, which are rated to treat cottonmouth, diamondback, pygmy, and coral snake bites.



The sliding glass door opens out to a wooden pergola, with two patio chairs and a BBQ grill sitting beneath it. The slimy trail of sloughed-off necrotic tissue continues across the flagstones and into the figure eight saltwater swimming pool behind the house. The pool is secured by a waist-high safety screen fence around its perimeter, but much of the netting seems to have been torn apart by bloody scratches. The FWC commissioner’s body is floating face-down near the center of the pool, oozing a dark red ichor. Temperature readings of the pool come out to 59° F (15° C).

A well-tended flower garden surrounds the swimming pool. A 50 year old tortoise lumbers throughout the yard, sampling the dandelions. Its hutch sits at the northwest corner of the yard. A wooden nameplate hangs off the hutch: “Johann”.

The Incursion

The body once known as Neil Greenwood is now a cold-blooded avatar of Yygg—but its transformative ritual is not yet complete. Within the salty-cold pool water, it is suspended in a state of hibernation until it encounters temperatures registering above 60° F (15.56° C). If the body is removed from the pool and not immediately transferred into a cool container, its metamorphosis will commence within minutes.

The body awakens and becomes the Manifestation (starting with 1d4 WP) when it is removed from the pool, or if the captive boomslang is harmed. It hisses rattling whispers through chattering teeth ; an Alertness check notices that the nearby tortoise has suddenly retreated into its shell, and the parrot in the house has stopped screeching. Every bird and reptile in the vicinity writhes and splits apart into a heap of snakes (1/1d6 SAN). Two snakes emerge from the house, three slither out of the tortoiseshell, and five more emerge from the edge of the property. Every snake in the neighborhood has obeyed the call of Yygg and is now rapidly converging on the Manifestation’s location. It eagerly gathers the snakes and shoves them through its mouth and gaping wounds (1/1d4 SAN, Manifestation gains 4+1d4 WP). Each turn, add a Bouquet of Snakes to the scene —their role is to act defensively, take hits for the Manifestation, and slow down the Agents. Combat begins with 1d4 Bouquets.

All snake-kin are vulnerable to strong odors, such as ammonia, which penalizes their rolls by -40%. They are also affected by low-frequency vibrations, penalizing all rolls by -20% until the vibrations stop. Exposure to Snake-A-Way granules further reduces snake rolls by -20%. All snake-kin become lethargic in cold temperatures and slip into hibernation within three rounds.

After five rounds of combat, the Manifestation will attempt to escape. It sprints to the guest bathroom and shoves itself down the toilet, shattering its own collarbones and hips in the process. The boomslang in Greenwood’s study somehow breaks out of its tank and places itself between the agents and the Manifestation to cover its escape.

The Sewer

The Agents have one last shot at catching the Manifestation. By using the sewer street access, they can cut it off at the pass just in time to watch it wriggle out from the sewer line. If the Manifestation hasn’t evolved into the Patriarch yet, it will now. (1d6/1d10 SAN)


If the Manifestation is dealt with, Yygg will not be able to strike again for one calendar year. Next python hunt, Commissioner Greenwood’s replacement will meet the same fate. A permanent solution is to abolish the hunt altogether, but that will take a legal uphill battle with the State of Florida. Gain 1d4 SAN.

If the Yygg Manifestation escapes through the Miami sewer network, it will be nigh impossible to track down. Reeling from the missed opportunity, the Agents will have to prioritize covering their tracks while the case officer assembles another team to address the oncoming disaster. Lose 1d6 SAN.

Wordcount: 1490


Manifestation of Yygg

That which once was Commissioner Greenwood. Unsteady and ungainly, like a newly-hatched chick.
STR 19 CON 21 DEX 18 INT 20 POW 40 CHA 0
HP 20 WP 0 ARMOR 3 Inflicts 1/1d6 SAN.
Alertness 60% Athletics 50% Dodge 50% Stealth 90% Unarmed 50%
Attack: Bite 70% 1d6 damage (applies Venom), Throngler (75%)
Venom: A bite attack that ends in an odd number injects Venom. Roll on the Snake Venom table.
Lose Your Limbs and Ascend: Spending 6 WP turns all birds and reptiles within 5 km3 into piles of snakes. Bugs, fish, and mammals are unaffected.
The Throngler: A pale, elongated foetal growth emerges from the avatar’s throat. It is three feet long, and its “head” (approximately the size of a mandarin) takes the form of a tiny screaming man’s face. The whiplike protrusion headbutts an agent within melee range, dealing 1d4 damage and inflicting 1/1d6 SAN unnatural. It is cold to the touch.
Mass Sacrament: Gains 1d4 WP per turn in warm temperatures. Each time it subsumes a Bouquet of Snakes, it gains 2 WP. The Manifestation loses 1d8 WP per turn in cold environments.
Metamorphosis: By spending 30 WP, the Manifestation can cast off its human form and ascend to Serpentes Patriarch. Its midsection splits in half, allowing its spine to erupt through its throat—with hundreds of tiny, quivering bones on each side, and its hindbrain perched all the way at the top.

Serpentes Patriarch

Humanity shed.
STR 35 CON 20 DEX 30 INT 30 POW 50 CHA 0
HP 60 WP N/A ARMOR 0 Inflicts 1d6/1d10 SAN.
Alertness 80% Firearms 60% Stealth 60% Unarmed 60%
Attack: Bite 70%, 1d8 damage (applies Venom), Firearms 60% (Each firearm held makes an attack per turn), Throngler (75%)
Serpentes Patriarch retains its previous abilities, and gains the following…
Summon Arms: The Patriarch calls upon its kin to bring armaments. It will receive two loaded guns (as determined by two 1d4 rolls) upon the backs of two Burmese pythons.
1. Colt Anaconda..44 Magnum. (1d12 damage)
2. Škorpion, chambered in.32 ACP. Previously used by the Cuban Revolutionary Armed Forces. (1d8 damage)
3. Remington 870 shotgun. 12 gauge. Police-issue. (2d8 damage)
4. M4 carbine. Fully automatic. (1d12 or 10% Lethality)
Colubrine Musculature: More snake than man. Immune to lethality attacks.
Curse of Yygg: Anyone who harms Yygg’s offspring and fails a Luck roll loses 0/1d4 SAN and is haunted for weeks by dreams of being consumed by snakes and reptiles. On a fumbled Luck roll, the affected agent is fated to fall to Yygg’s Curse within the year.

Bouquet of Snakes

For abstraction’s sake, a Bouquet of Snakes represents 4-6 snake individuals.
STR 12 CON 8 DEX 10 POW 5
Alertness 60% Climb 50% Dodge 50% Stealth 90% Swim 50%
Attack: Bite 70%, 1 damage (applies Venom). Sworn to defend Yygg. Will only attack if unarmed combat is attempted.
Venom: A bite attack that rolls an odd number injects venom. Roll on the Snake Venom table.

Snake Venom

Antivenom treatment can cost upwards of $100,000 in the United States.
1d4 On a lethality roll failure, the victim tests CON x 5. Success receives half damage; a Critical Success receives 1 damage; a Fumble receives double damage.

  1. Cottonmouth: Delivers a painful bite and a lethal dose of cytotoxins. Proteolytic activity can result in severe tissue destruction, necessitating amputation in some cases. Death can occur in 6 hours. (20% lethality, additional 20% lethality in 6 hours if untreated. If the agent survives the second roll, they lose a limb.)
  2. Diamondback:** Bad reputation. Eastern variety. Its venom is highly necrotizing and leads to hemorrhaging. Death can occur in 24 hours. (30% lethality, death in 1D20+4 hours if untreated.)
  3. Pygmy: Cannot deliver a fatal bite. Cytotoxins cause minor necrosis at the site where skin was broken. (1d6 damage)
  4. Coral: Red touch yellow, kill a fellow. Gun-shy, and bites only if grabbed. Delivers neurotoxic venom that causes the muscles to seize up. Death can occur within 16 hours. (10% lethality, death in 1D10+6 hours if untreated.)

Wild Card! Boomslang: Technically invasive. Only applies to the snake in the glass terrarium. Delivers hemotoxic venom that clots the blood. Without antivenom and blood transfusions, death from respiratory arrest and brain hemorrhaging can occur within 24 hours, and the victim bleeds from every pore in their body. (40% lethality, death in 1D20+4 hours if untreated.)


Minimum Viable Population was written by Tuesday 8:00 for the 2023 Shotgun Scenario contest.

The intellectual property known as Delta Green is ™ and © the Delta Green Partnership. The contents of this document are © their respective authors, excepting those elements that are components of the Delta Green intellectual property.