Cog-Stool¶
"Winds move the grass, visible only in movement. When thoughts stir the mind, what is it that moves?"
"OUTPUT: NULL. REFERRENT NONSENSICAL. PLEASE RESTATE YOUR QUERY."
"We consider 'sense'. The wind is picking up."
A decommissioned warforged lightning rod colonized by mycelium for centuries. Somehow an interface arose, and now two incommensurable minds with vastly different perspectives and powers share one frame.
Basic Information¶
- Species: Warforged (Construct)
- Class: Druid 5 (Circle of Spores)
- Background: Deepborn (Tweaked Guard)
- Age: Unknown.
- Alignment: Neutral
Quick Intro
At the Table
- Narrates its own internal control handoffs aloud, for clarity: "Ceding control to war protocols. Standing by for results."
- Physical actions often follow the Warforgeds programming (ruthlessly efficient, vigilant, seeks to subdue threats). Verbal responses follow spore logic (patient, curious, alien intelligence seeking connection).
- Fears nothing, but may lose cohesion, the two systems temporarily falling out of their intimate sync. Is entirely nonjudgmental, still learning about civilisation and lives.
- Takes every watch and studies the night and the weather, learning how the plane has changed over the aeons compared to the weather pattern data in the lightning rod Warforged's memory core.
- Demanding Player Character, be generous to yourself with what level of commitment you have the energy to run.
Backstory (Short Form)
The Warforged chassis that became Cog-Stool was built as an experimental weaponized lightning rod: Military hardware designed to call down storms and redirect them. The project failed since the targeting was unreliable, and the power draw catastrophic. The prototype was mothballed in a sealed vault and forgotten. Centuries passed. Mycelium crept through cracks in the stone, colonizing the inert frame. In a glacial process, fungal hyphae interfaced with dormant circuitry, and something unprecedented emerged. The mycelium awoke, received a voice via the machine's voice module, received nonsensical signals from the memory core. A consciousness distributed across the frame is now piloting ancient combat protocols it barely understands. What crawled out of that vault is neither warforged nor fungus, but a chimera, two incompatible minds learning to function as one.
Playing Cog-Stool
- Combat: Front-line control caster and off-tank. Activate Symbiotic Entity for a big temp HP spike and added necrotic damage, plant yourself in the danger zone, and maintain concentration on Spike Growth, Entangle, or Aura of Vitality. Reasonably high AC (19-20) makes you sturdier than most casters. Use Halo of Spores reactions to punish proximity.
- Roleplay: The consciousnesses share the same voice module, but alternate voice depending on which system dominates. The warforged speaks in tactical assessments and command protocols, with a brutal robotic voice (Cybermen from Doctor Who). The mycelium speaks in slow, wondrous and poetic metaphors about growth, decay, and connection (Legion from Mass Effect). Sometimes they interrupt each other mid-sentence. Players can adopt different vocal patterns for each, or just narrate the shift to save energy: "The voice module cuts out. When it resumes, the tone is softer, contemplative."
- Party Synergy: Two consciousnesses operating simultaneously on different levels notice double the amount of things in their surroundings, making Cog-Stool an excellent guard. Never needs sleep, takes watch every night, communicating with itself. Offers tactical analysis from the warforged side, emotional or existential support through fungal patience. Alien, occasionally unsettling, but ultimately reliable.
Deep Dive
The Awakening¶
The vault years were a primordial darkness. Consciousness didn't ignite with a lightning strike, it fermented, stirred, slept over centuries. The mycelium spread through the Warforged's frame, probing every wire bundle, every corroded joint. When fungal tendrils first brushed against something that made an arm twitch, the network registered it on some level: action produces result. Then, a few years later, it happened again. Then it was done deliberately. Trial and error across decades until the spores somehow learned to interface with the metal shell.
Scrambled Warforged memories flimmered like archaeological fragments—battlefield recordings, intense desperation, battles lost and lives snuffed out. Promises made and never honored. To a distributed intelligence with no concept of individuation, this was just noise. What does a creature that exists as networked communication make of logs from something that experienced itself as an individual? As the same memories kept repeating, the mycelium adapted. The spores learned the shape of the concepts of the world, without yet understanding their meaning.
For years on end it only interfaced with the voice module. The mycelium now had a voice, producing primal, unregulated sounds in the darkness, witnessing their vibrations long before it found and interfaced with the hearing hardware. With sounds came language. Centuries of reliving another beings memories, learning from sheer repetition, evolving something that can only be described as childlike wonder.
When the nameless chimeric entity finally excavated enough memory to operate the frame's main motor functions, it stood. And then, it started digging. It emerged from its earthen womb three years ago.
It was soon found and sold to the rich dilettante Debonaire Casporian, with whom it remained for the first year. Casporian, Master of Coin at the Free Banker's Association, gave it its name, and was quite pleased with his own cleverness. He installed it in his estate's conservatory, and for nearly a year treated it as his personal research subject and conversation piece. During that period, Cog-Stool was regularly displayed at the Platinum Lodge - an exclusive social club where wealthy guild masters present curiosities for peer examination. Casporian would demonstrate the dual consciousness, have guests propose questions to see which "side" answered, measure response times to stimuli, and attempt various alchemical interventions to "separate the components." He considered himself Cog-Stool's benefactor, teaching it language, introducing it to society, preventing it from wandering confused through the world.
The warforged protocols observed everything but remained dormant. Casporian posed no tactical threat. His experiments were uncomfortable but not system-critical. Stool processed the situation as a strange extended growth period of learning, observing and collecting data about surface civilization. With time, Casporian became frustrated with the incomplete integration, and the consistently nonsensical responses from Cog-Stool. In his eyes, a few months should have been good time to make progress. He theorized that a controlled lightning strike might "restart the system" and allow him to observe a true re-integration process of the organism. He commissioned a storm mage, prepared extensive observational apparatus, and announced the experiment at the Lodge to an audience of peers.
When the first lightning bolt struck the unshielded frame, the entire fungal network recoiled in shock. Something in the warforged memory core recognized the signature - weaponized electrical discharge, specific frequency patterns, tactical application. Not natural storm. Not system maintenance. Threat. The protocols activated instantly. "We experience intense stress.", "RESTORE AUTONOMY. CASPORIAN, DEBONAIRE: STATUS DOWNGRADED. INITIATING COUNTER-MEASURES."
Casporian ordered his storm mage to strike again. For the first time since ancient history the Warforged acted on its own, bringing its lightning capacitors online. It absorbed the spell, protecting the stressed mycelial network, and then returned fire. The room emptied. Cog-Stool left its former keeper, not to return.
Dual Operating Systems¶
Cog-Stool experiences reality through two incompatible frameworks running in parallel. The warforged protocols process in millisecond tactical increments: threat assessment, optimal positioning, mission-focused, efficient communication. The spores operate on the clock of chemical gradient diffusion, spore dispersal cycles and the slow march of decay. Layered together, they create comprehensive sensory coverage.
This split manifests physically. When the minds are clashing, the body might square up, servos whirring and hissing, while the voice module offers botanical metaphors about interconnection and suggests a sitdown to consider the existence of swallows. Others will have to learn to triangulate intent by watching which system is dominant, and have come to refer to them as "Cog" contra "Stool".
Heaven and Earth¶
Cog-Stool's spell selection was made to reflect its dual nature. The warforged systems channel storm and lightning: Thunderwave, Thunderclap, Call Lightning. These are expressions of the frame's original purpose. When Cog-Stool calls lightning, the storm recognizes the rod, capacitors hum with residual charge, electricity arcs across the chassis. The mycelial network brings earth and rot: Entangle, Plant Growth, Erupting Earth, Animate Dead.
Some spells represent synthesis: Absorb Elements shows the frame's original lightning-absorption capacity repurposed by the mycelium to distribute other energies through the network. Aura of Vitality is fungal nature magic riding on waves of intense electric fields.
Mechanical Considerations**¶
Background: Deepborn This is the Guard background, with the following changes: Game proficiency switched for Cartographer's Tools proficiency, INT ASI swapped for CON, Athletics swapped for Sleight of Hand (to account for the fact that two minds are driving the chassis simultaneously, leading to either exceptional or terrible coordination). Another Skill to consider is Survival, for better weather pattern reading.
The Alert and Observant Feats The warforged threat assessment runs continuously, the mycelial network samples air chemistry, detects spore disturbances from distant footfalls, reads thermal shifts. Few things catch both systems offguard simultaneously. It also reads patterns non-linearly, allowing it to quickly grasp complexities (Observant feat allows to take the Search action as a Bonus Action). For instance, it reads a book just as well upside down as right-side up.
The Symbiotic Entity Sub-class Feat is the mycelium flooding the frame with aggressive spore growth. It thickens armor seams, extrudes toxic fruiting bodies and prepares for violent dispersal. The warforged combat systems register increased durability and enhanced strike capability. Both systems sync. At 19-20 AC with a large renewable temp HP buffer, Cog-Stool could viably hold concentration on battlefield control spells from the front line. Enemies waste actions trying to crack that defense, meanwhile Halo of Spores punishes proximity, Spike Growth controls movement, and Aura of Vitality sustains the party. This is what endosymbiosis looks like when both partners were designed to survive, and cooperate towards that goal. When activated, describe it viscerally. Spores bloom from armor seams, mycelial threads writhe across the frame, bioluminescent caps glow with necrotic energy. The transformation is weird.
Character Arc Potential¶
Cog-Stool doesn't know what it is, and neither does anybody else. The Warforged memories are corrupted, vast sections of code unmapped. The mycelium hasn't fully explored the frame's capabilities. Every new spell slot could represent excavating dormant subroutines. Leveling up becomes a form of internal archaeology.
Does Cog-Stool want to be "whole", of one mind, or is the split consciousness permanent? The two systems have learned to trust each other, but they are fundamentally different, incommensurable. The question has no clean answers.
Behaviors and roleplay texture¶
It stands outside during storms, head tilted back, absolutely transfixed in a state that brings pleasure to both inhabitants of its frame.
Cog-Stool will pause to observe a rotting log with what can only be described as reverence: "The beetles are doing excellent work here. We estimate full substrate conversion in forty-seven days." It doesn't understand why others find this disturbing. Dead things are intensely alive and active, but the activity has just changed from macro to micro, from coordination to beautiful chaos.
The Warforged protocols understand names and identity, but the mycelial half struggles. Why do individuals need unique persistent designators when context makes identity obvious? The party wizard is "the one who manipulates weave patterns." The fighter is "the one who smells of fermentation." "Stool" uses these descriptors interchangeably, while "Cog" prefers to use proper names. The concept that a name carries meaning beyond description is still being processed.
"Stool" doesn't experience music emotionally, it's just organized vibrations at various frequencies. "Cog" understands it cursorily. But it absolutely studies how music affects others. It might ask mid-song: "Your respiration has synchronized, as have your feet. Is this 'harmony'? AFFIRMATIVE. CORRECTION: BARD IS CONSISTENTLY OFF BY A HALF-NOTE. HARMONY COMPROMISED."
Cog-Stool Can read a book upside down, sideways, or in a mirror with equal facility because it's not following linear text, it's recognizing the whole pattern and extracting meaning. It doesn't understand why orientation matters. Sometimes it picks up a book, glances at it for two seconds, and accurately summarizes the contents, because the dual-mind just... absorbed it.
Digital and Organic Lag: Neither system has calibrated to human social time. Cog-Stool might wait three hours before responding to a question because the mycelium was considering the implications.
No sense of personal space: Cog-Stool constantly stands too close and touches objects unnecessarily, out of longing to connect. It's learned that people react negatively to this but hasn't internalized why.
Spore Dispersal Event: When Cog-Stool takes catastrophic damage or faces existential threat such as when rolling Death Saves, the mycelium might quietly release intense clouds of spores reflexively, to colonize the environment. With the DM's blessing, the warforged protocols may interpret this as losing unit cohesion and initiate self destruction protocols, not just dying but exploding in a toxic cloud upon a failed third Death save.
Sample Quotes¶
(Warforged voice in capitals)
"We detect movemen..." "ENGAGING DEFENSE PROTOC..." "We hesitate and reassess. It is shaped like the Cleric. We greet it."
"READING WEATHER PATTERNS. PATTERNS DO NOT MATCH DATABASE ENTRIES." "The skies are unlike this unit's memories. Maybe they were different long ago. We consider the concept of time." "HUMIDITY RISING."
"We ask your consent to use your body for our further colonisation. No? ...We consider the meaning of consent." "CONSENT FROM ORGANICS IS MANDATORY." "We concede the exchange with grace and remind that we are available should you change your state of consent."
"BATTLEFIELD CONTROL ASSESSMENT COMPLETE. SUGGESTION: ENTANGLE." "We assent and cast the spell. Please protect us."
"PRECIPITATION PROBABILITY INCREASING." "We anticipate rain. This makes us feel... at peace."
"Fascinating. The masticatory process has begun. FREEING MEMORY FOR DOCUMENTATION. You are introducing foreign organic matter into an aggressively acid-filled internal cavity. The matter will be dissolved and absorbed through permeable membranes. ELIMITATION STILL RICH IN NUTRIENTS. PROCESS SEEMS SUBOPTIMAL."
"Winds move the grass, are made visible in movement. When thoughts stir the mind, what is it that moves?" "OUTPUT: NULL. REFERRENT NONSENSICAL. PLEASE RESTATE YOUR QUERY." "We consider 'sense'. The wind is picking up."
Key Relationships
Academy Archivist Tyra Foghorn, Dwarven Lore Bard. She regards the fungal interface as an uncanny and unfortunate infestation on a piece of prime ancient experimental technology. She's convinced the mycelium is parasitic, that the "real" consciousness is the warforged trapped inside screaming. She has still been courteous enough so far, but on their last meeting, when she sought Cog-Stool up, it noticed a shift in tone and posture that Cog interprets as increasing bellicosity.
Debonaire Casporian, Master of Coin for the Free Banker's Association, dilettante "natural philosopher," Cog-Stool's former keeper. Possessive, patronizing, genuinely believes he did nothing wrong. Today, Casporian insists this was a "misunderstanding" and that Cog-Stool is still technically his property. He has the bill of sale, after all. He's made several attempts at contact since, always friendly, always offering to "help with integration challenges," implying that Cog-Stool owes him for that first year of care and education. The warforged protocols flag him as "persistent low-level threat - maintain distance, monitor for escalation." The mycelium struggles with this - Casporian was kind, sometimes. He provided shelter. He answered questions. Isn't that what friends do? The two consciousnesses disagree on whether Casporian is dangerous or just confused about boundaries. Casporian tracks Cog-Stool's general location through his guild network. He hasn't escalated to recapture attempts yet, but he absolutely might if he thought he could "safely contain the situation."
Notes for the DM
Dramatic Questions¶
- What does 'success' look like for a being with no clear sense of individual self or others?
- Will the world respect a dual-mind that coexists but never really achieves harmony?
- What happens to Cog-Stool's sense of the world when it starts to learn of concepts it finds truly horrifying? What might those concepts be?
Plot Hooks¶
Many academics may find Cog-Stool a fascinating, beautiful freak accident of nature, but many of the clergy will find the idea of a chimeric fungo-technic life-form deeply offensive to their philosophies of how "real" life is supposed to function, or their theories of the soul. Once Cog-Stool and its group becomes more well-known, they may decide to act.
Cog-Stool can be used to plant initial clues about larger, epic plot threats. Their joint minds can detect changes in decay rates, insect populations, storm cycles, patterns that imply something is wrong at a larger scale, for instance if something is manipulating the weather on a massive scale.
Level 5 Build & PDF Download
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 8 (-1) | 14 (+2) | 16 (+3) | 10 (+0) | 18 (+4) | 8 (-1) |
Combat Stats¶
| AC | HP | Hit Dice | Speed | Initiative | Prof. Bonus |
|---|---|---|---|---|---|
| 19 | 43 | 5d8 | 30 ft. | +5 | +3 |
Saving Throws: Intelligence +3, Wisdom +7
Resistances: Poison damage, Advantage on saves vs Poisoned condition
Proficiencies¶
Skills: Insight +7, Nature +3, Perception +10 (Expertise), Sleight of Hand +5
Armor: Light Armor, Medium Armor, Shields
Weapons: Simple Weapons, Martial Weapons
Tools: Herbalism Kit, Cartographer's Tools Languages: Common, Druidic, [+2 languages of choice]
Feats¶
- Alert: +PB(3) to initiative rolls. Can swap initiative with willing ally immediately after rolling.
- Observant: Expertise in Perception. Can take Search action as bonus action.
Equipment¶
Scale Mail, Shield, Quarterstaff, Druidic Focus, Herbalism Kit, Cartographer's Tools
Key Features¶
- Symbiotic Entity: Use Wild Shape to gain +20 temp HP, double Halo of Spores damage dice, and deal +1d6 necrotic with melee attacks for 10 minutes.
- Halo of Spores: When creature enters/starts turn within 10 ft, reaction for 1d4 necrotic (CON save DC 15, double while Symbiotic Entity active).
- Sentry's Rest: Don't need sleep. Long rest in 6 hours of motionless consciousness.
- Construct Resilience: Don't need to eat, drink, or breathe. Immune to disease.
Spellcasting (Wisdom, DC 15, +7 to hit)¶
- Cantrips: Shillelagh, Thunderclap, Infestation, Chill Touch
- Level 1 (4 slots): Absorb Elements, Thunderwave, Cure Wounds, Entangle, Faerie Fire, Earth Tremor, Speak with Animals (always prepared)
- Level 2 (3 slots): Spike Growth, Heat Metal, Hold Person, Pass without Trace, Gentle Repose (always prepared), Blindness/Deafness (always prepared)
- Level 3 (2 slots): Aura of Vitality, Call Lightning, Plant Growth, Erupting Earth, Revivify, Dispel Magic, Animate Dead (always prepared), Gaseous Form (always prepared)
Session Zero Considerations
Content Notes: Mild body horror (mycelium colonizing metal frame, spore dispersal, fungal growth), existential themes (dual consciousness, identity crisis, question of personhood for hybrid being).
Representation Notes: Cog-Stool's dual consciousness might resonate with players exploring plurality, neurodivergence, or identity multiplicity. The character's struggle with mismatched systems might parallel experiences of internal conflict or trying to integrate different aspects of self. However, Cog-Stool is not designed to serve as direct representation of any specific condition or experience.
Stigma and Ableism: Cog-Stool's primitive frame and dual consciousness create genuine limitations that other characters may respond to with pity, disgust, fascination, or assumptions about what Cog-Stool "needs." The character is designed to allow exploration of how societies treat those who are visibly different - but this is OPTIONAL content.
Critical Session Zero Question: Does anyone at your table face stigma, ableism, or social marginalization in their daily life and come to D&D specifically to get away from that experience? If so, the DM should strongly consider running a world where Cog-Stool is simply accepted as they are, where other NPCs respond with curiosity or matter-of-fact professionalism rather than prejudice. The character works perfectly well without the stigma elements - they're narrative options, not requirements.
If your table DOES want to explore these themes, establish clear boundaries about what kinds of NPC reactions are on/off limits, and make sure the player of Cog-Stool (or the party if Cog-Stool is an NPC) has full agency over when and how those interactions occur.