By Anvil N Ink Publishing · Updated May 2026 · 7 min read
Publisher’s note: this is one of our own titles, so what follows is a straight breakdown of what works, who it’s for, and who should skip it — not a sales pitch.
The Colossus Autopsy is a mature, 5e-compatible body horror one-shot for 2–3 players that runs in 2–3 hours. It sends a small group into the decaying anatomy of a 60-foot storm giant for tactical exploration and a genuine moral choice. It’s built for adult tables that want real, unsettling horror rather than a gross-out — and it is emphatically not for kids or squeamish groups.
The Colossus Autopsy comes out of a frustration with horror one-shots that mistake gore for fear. An early draft was wall-to-wall viscera and it played like a butcher’s inventory. What finally worked was restraint: a single warm vein, a chamber that breathes, the slow understanding of where you actually are. This page is an honest accounting of whether that landed.
What’s included in The Colossus Autopsy?
The Colossus Autopsy is a complete, zero-prep one-shot — you read the overview and run it the same night, no separate setup required. The giant’s body is structured as a descending sequence of encounter areas, each built around a distinct anatomical hazard, so exploration and combat share the same space rather than alternating.
Inside you get the full adventure text, the threats you meet within the corpse with their stat blocks, the central moral decision that drives the ending, and the framing that turns a dungeon crawl into something that crawls back. Combat appears throughout; skill checks set how dangerous each stage becomes, not whether a fight happens. The descent is laid out as a single forward path with no backtracking, which keeps the tension from leaking out between scenes and means a busy GM never has to track a branching map mid-session. It assumes characters around levels 2–3 and a table of two or three players — the small-group size that all Anvil N Ink adventures are designed around.
Why does “the body is the dungeon” actually work?
Most dungeons are neutral spaces — stone rooms that happen to contain enemies. The Colossus Autopsy makes the location itself the source of dread, which changes how players move through it. Every doorway is a sphincter or a torn membrane; every corridor is a vessel; the “weather” is the giant’s slowing pulse. Players stop treating the map as scenery and start treating it as something that might react to them.
That design choice does two things at once. Mechanically, it lets terrain carry the threat, so a 2–3 player table doesn’t need to face crowds of monsters to feel pressure — a single hazard with a countdown is enough. Emotionally, it keeps the horror personal: the players chose to climb inside this thing, and the deeper they go, the harder that choice is to take back. The dungeon’s structure and the adventure’s meaning are the same structure. That’s the strongest part of the design, and the part that’s hard to copy by bolting gore onto an ordinary crawl.
Who is this adventure for?
This is an adults-by-default adventure. It suits experienced or new GMs who want to run horror that actually disturbs, small groups of 2–3 players, and tables comfortable agreeing to mature body horror before play. If your group enjoys the slow-dread, “what is wrong with this place” register over hack-and-slash, it lands hard.
It is not for children, for casual one-shot nights with strangers, or for players who haven’t consented to graphic content. Body horror is the single most consent-sensitive genre in the hobby, and this one earns the 18+ framing. If you’re unsure how to set that up safely, the guide on how to run body horror in D&D walks through it, using this adventure as its worked example.
How long does it take to run?
Plan for 2–3 hours, with most tables landing near the middle of that band. It’s designed to run about two and a half hours start to finish with two and three players, including the consent conversation up front and the fallout after the final choice. The pacing is deliberately compressed — a single descent with no backtracking — which is what keeps the dread from leaking out between scenes. If your group lingers on description and roleplay, expect the upper end; if they push forward hard, it can come in just under two hours, though rushing this one costs you most of what makes it work.
Strengths and weaknesses
The honest version, because a publisher’s review of its own book is worthless without it.
Strengths: the central conceit — the body is the dungeon — does real mechanical and emotional work, not just set dressing. The restraint pays off; tables report the quiet beats unsettling them more than the explicit ones. And the closing moral choice gives the session a point beyond survival, which is what people remember a week later.
Weaknesses: the audience is narrow on purpose, so this is the wrong pick for a mixed or casual table. It demands a real consent setup, which adds a few minutes and a little social effort some groups won’t want. And if your players want a straightforward kick-the-door dungeon, the deliberate, claustrophobic pacing will feel slow to them. None of those are bugs — but they’re reasons it isn’t for everyone, and you should know that before you buy.
How does The Colossus Autopsy compare?
If you’re weighing it against Anvil N Ink’s other horror one-shots, here’s the honest split:
| Adventure | Horror type | Intensity | Players | Best for |
|---|---|---|---|---|
| The Colossus Autopsy | Body horror | Mature / 18+ | 2–3 | Adult tables wanting visceral dread |
| The Spider’s Seminary | Infestation / survival | Dark, less explicit | 2–3 | Groups wanting tension plus combat |
| Ashcroft Manor | Gothic haunting | Atmospheric | 2–3 | Slow-burn haunted-house fans |
All three are zero-prep, 2–3 hour, small-group adventures. The Colossus Autopsy is the most explicit of the set; if that’s a step further than your table wants, the other two reach for dread without the graphic content.
A taste of the adventure
The first chamber is the worst, because nothing has gone wrong yet. You climb in through a wound that has stopped bleeding and find a cavity the size of a hall, ribbed and pale, the air thick and faintly sweet. There is a sound you can’t place until you stop moving — a slow, wet settling, like a house cooling at night, except the house is not cool. It is warm. Everything here is warm.
Your torchlight catches a vein the width of a road running floor to ceiling, and the surface of it shifts, just slightly, as if something is still being carried along inside. Nothing attacks. Nothing needs to. The horror of this room is that the players understand, all at once and without being told, exactly where they are standing — and that they came in here on purpose. That recognition is the whole design. What waits deeper is louder. This is quieter, and it’s the part they describe afterward.
Where to buy The Colossus Autopsy
The Colossus Autopsy is available in paperback and ebook on Amazon and as a PDF on Payhip. Pick your format from the buttons on this page. If you want to read the technique before you run it, start with the body horror GM guide or browse more small-group adventures for 2–3 players.
Frequently Asked Questions
Can I run this with 3 players? Yes. It’s built for 2–3 players at roughly levels 2–3, like every Anvil N Ink one-shot.
Is it appropriate for younger or mixed tables? No. It’s mature body horror, designed for adult groups who’ve agreed to graphic content. For all-ages horror, run something else.
How much prep does it need? None. It’s zero-prep — read the overview and run it the same evening.
Do I need D&D Beyond or any extra tools? No. It’s 5e-compatible and runs straight from the book with standard dice.
Should we use safety tools? Yes — strongly. Set lines and veils and keep an X-Card on the table. The fear works better when the room feels safe.
About Anvil N Ink Publishing
Anvil N Ink Publishing makes small-group D&D 5e one-shots and guides for 2–3 players and a single 2–3 hour session. Explore the full library of small-group adventures and guides.
The Colossus Autopsy is a mature body horror D&D one-shot that proves restraint frightens a table harder than gore ever could.
Get Your Copy
Choose your preferred format