On screen for the table · tap DM Tools for dice, tracker, clocks, calendar and timers · press ? for keyboard shortcuts · Player casts a spoiler-safe view to a TV · Ctrl/Cmd + P prints on a light, ink-friendly layout.
A Creature Keeper · Long Island Dungeon Master
It cannot move, it cannot chase you, and it will take the whole party if one person crawls.
At a glance: CR 3 · levels 2 to 5 · a trap that never lies · the only way in is a three-foot tunnel, and the water at the far end is real.
Green, about a mile out, and it stays green as you close on it. Stalks the height of a man in a ring maybe sixty feet across, a deep band of shade inside them, and water. You can hear it from where you are standing. There is one gap in the stalks, about three feet wide, and it goes all the way through.
A thirstthorn grows in a ring around real water, in country where real water is the only thing anybody is looking for. It is not disguised and it is not an illusion. The shade is shade, the pool is a pool, and the plant never lies about anything. It just charges, and the toll is that the only way to the water is on your hands and knees.
Target band levels 2-5. One thorn: raw 700, adjusted 700 at the single-monster multiplier of 1.0. Two thorns: raw 1,400, adjusted 2,100 at the two-monster multiplier of 1.5. Every figure re-run at the calculator, none of it read off the page.
One thorn against four 2nd-level characters is 700 adjusted against thresholds of 200 / 400 / 600 / 800, a Hard fight. The same thorn is Medium at 3rd level (300 / 600 / 900 / 1,600) and Easy at 4th (500 / 1,000 / 1,500 / 2,000). Two thorns against four 5th-level characters is 1,400 raw at the two-monster multiplier of 1.5, so 2,100 adjusted against 1,000 / 2,000 / 3,000 / 4,400, which is Medium. Both stands are rooted and both are present from round one: nothing arrives later, so that tier is the whole fight rather than the back half of it.
Open DM Tools. The thorn is already sitting in the combat tracker with its tactics attached. Three clocks are built: the crawl down the tunnel, the stalks being cut through, and the fire taking hold. Both tables roll from the table roller, so you never have to find your place on a page at two in the morning.
Damage Vulnerabilities. fire
Damage Resistances. piercing, slashing. The stalks are hollow and a blade goes through them without finding anything.
Senses. blindsight 30 ft., passive Perception 10
Drawn to. warm blood. It grew around the water so that the thirsty would come to it.
Challenge. 3 (700 XP) · a trap for levels 2 to 5
False Oasis. From outside the stand it reads as shade and open water, because it is shade and open water. A creature with reason to be suspicious can spot the trap with a DC 15 Wisdom (Perception) or Intelligence (Nature) check before entering.
Choking Tunnel. The only path to the pool is a three-foot tunnel through the stalks. A Medium creature squeezes through it at half speed.
The heart-cluster. Hit points are the heart-cluster at the pool edge. That is the only part of the stand that dies.
A deliberate outlier. Forty hit points is low for Challenge 3 and that is on purpose: this is a glass cannon sitting behind two resistances. Piercing and slashing are the damage types a party brings by default, and the plant heals 5 a round off every creature it is holding, so the honest hit-point number in play is a good deal higher than the one printed. Bring fire and it dies in two rounds. Bring swords and you are there all afternoon.
Thorn Tendril. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 6 (1d6+3) piercing damage, and the target is Grappled (escape DC 13).
Blood Drain. At the start of the thirstthorn's turn, each creature it has Grappled takes 5 (2d4) necrotic damage, and the thirstthorn regains that many hit points.
Roll it here.
It does not chase, because it cannot. It waits, and it punishes greed. The water at its heart is real and that is the horror of it. It opens on whatever is fifteen feet into the tunnel and lying down, and it holds rather than kills, because a held creature is a creature it is still drinking. Fire ends it fast. Hacking at hollow stalks barely works, and every round somebody spends hacking is a round somebody else is being drunk.
Now this one I admire. I spent four years being a wardrobe in a hallway nobody used, which taught me patience I have never once been thanked for, and here is a creature that has taken the same lesson and put a drink at the end of it. It does not lie. It does not creep up on anybody. It simply stands in the one place everybody wants to be and lets them talk themselves into it, which is the purest form of the art and I will not hear otherwise. Do not let your players burn it in the first thirty seconds. Let them want the water first.
Roll the first one when you place a stand, before the party is anywhere near it: what the thorn last fed on sets the tunnel, the tells at the mouth, and what everybody is standing in when it dies. Roll the second the moment real flame reaches the stalks.
| d20 | What it has already drunk |
|---|---|
| 1 | Nothing, for a long time. This stand is starving. The stalks are thin, the shade is patchy, and the tunnel is wide enough to walk into stooped. It will take the first thing that comes and it will take it fast, and a starving thirstthorn opens at the tunnel mouth rather than waiting for the pool. |
| 2 | A caravan's lead ox, three weeks ago. Fat, slow and enormously green. The tunnel has narrowed to barely three feet because the stalks have thickened. It is not hungry, which means it waits for the second person in rather than the first, and there is a picked ox skull at the pool edge in plain sight. |
| 3 | Something that was already poisoned. The pool is fine. The plant is not. It attacks on a delay, misses more than it should, and any creature that spends a full round watching before entering notices the tendrils twitching out of time with each other. Treat it as having disadvantage on its first attack. |
| 4 | A rider and not the horse. The horse is still here, alive, hobbled twenty feet out in the open, thin and calm and utterly uninterested in the shade. The horse is the only moving thing in the clearing, and ten minutes is exactly as long as the thorn needs. |
| 5 | The last four people who tried to burn it. There are four separate scorch marks on the outside of the stand at four different ages, and the newest is a month old. Whatever they are doing wrong, they are doing it from the outside. The stand is thick enough now that a torch at the edge does nothing. |
| 6 | Rain. There has been weather, the seep is running high, and the pool is up over the lip and spilling into the sand in a dark fan twenty feet long. The plant is slack and slow and much less interested. It attacks only what comes all the way to the water, and a party that fills skins from the overflow can leave without ever meeting it. |
| 7 | A snake with a nasty reputation. The tendrils carry it now. The first creature Grappled takes the normal damage and must also make a DC 13 Constitution saving throw, taking 4 (1d8) poison damage on a failure and half as much on a success. Once only. After that the stand is clean. |
| 8 | A child's donkey, and the child got away. There is a village six miles from here that knows exactly what is in this stand, has known for two years, and has said nothing to any traveller because the water is the reason anybody stops and the stopping is the reason anybody trades. Somebody in that village will not meet the party's eyes. |
| 9 | A creature much bigger than it. The stand is deformed. One whole side is collapsed outward and there is a gap in the ring a Medium creature can walk through upright without using the tunnel at all. The plant knows the gap is there. It has been waiting for somebody to use it. |
| 10 | Two seasons of small birds. Barely anything. It is alert, quick and mean, and the stalks are studded with small dry bodies the birds' own weight could not shake loose. Anyone who looks at the stalks before entering gets the whole story for free and does not need a check for it. |
| 11 | A surveyor with a full satchel. It drank him and kept the rest. The satchel is in the pool, waterlogged and legible, and it holds a working chart of every reliable water source for two hundred miles. That chart is worth more than the adventure it is sitting in, and the party has to go in and get it. |
| 12 | Its own neighbour. There were two stands here. The bigger one grew across the gap and drank the smaller one over a year, and the dead ring is still standing twenty feet off, hollow and safe and perfect cover. Start the fight with that dead ring already on the map. |
| 13 | A courier, last week, and the horse went on. Somewhere ahead of the party on this road is a horse with an empty saddle and a sealed bag, and somebody is waiting for what is in that bag. This is the row that turns a monster into three sessions. |
| 14 | Salt water. The seep went bad and the plant has been drinking it anyway. It is dying and it is furious. Give it 10 fewer hit points and let it fight to zero with no interest at all in whether it survives, because it will not. The pool is undrinkable and looks perfect. |
| 15 | Fire, once, and it healed. There is a band of black scarring at knee height all the way around the outside and new green growing straight out of it. The party can see, before they commit to anything, that somebody already tried the obvious answer here and it was not enough. Doubling the fire is the correct response and somebody has to think of it. |
| 16 | A pilgrim who is still alive in there. Four days in, Grappled, conscious, at 2 hit points, and quiet because he stopped shouting on the second day. He is audible from the tunnel mouth if anybody stops talking and listens. Everything about this encounter changes and none of the numbers do. |
| 17 | More than it can hold. The pool is red at the bottom and the whole stand smells like a butcher's yard in summer. Nothing is hidden and nothing needs a check. A party that walks away from this one has read the situation correctly and should be told so. |
| 18 | A wagon, and the people walked. There is a stripped wagon frame in the ring with the stalks grown through the spokes, and the wagon was full when it stopped. Whatever was in it is in the pool, under two feet of water, and its outline is visible from outside the ring. |
| 19 | The garrison's water carrier. This stand is within sight of a manned tower, the tower knows, and the tower's standing order is to let it stand because a thirstthorn on the free road is the reason everyone pays the toll for the guarded well. Somebody up there is watching the party through a glass right now. |
| 20 | Nothing at all, because it has only just arrived. This ring is one season old, the stalks are waist high, the tunnel is not a tunnel yet, and the entire thing can be killed in an afternoon by four people with hand axes and no risk whatsoever. Nobody has, because nobody comes this way any more, and the reason nobody comes this way any more is the problem the party actually came here to solve. |
| d12 | What the fire does |
|---|---|
| 1 | It goes up like paper and it goes up fast. The whole ring is alight in two rounds. Anything still inside the tunnel makes a DC 13 Dexterity saving throw, taking 7 (2d6) fire damage on a failure and half as much on a success, and the pool is ruined. |
| 2 | The stalks scream. Hollow tubes full of hot sap. It is a noise nobody at the table was ready for, it carries for a mile in flat country, and by morning something has come to see what made it. |
| 3 | Only the windward third catches. The plant takes the damage, loses a quarter of its reach, and goes on fighting from the green side. The party now has a burning wall between them and the tunnel mouth. |
| 4 | It burns and the water is fine. The seep is deep and cold and the ash floats. Give them this one sometimes. A table that has been told all week that fire costs them the water should occasionally find out that the world is not a machine for punishing them. |
| 5 | It lets go of everything it is holding. Every creature it has Grappled is released at once, including the ones nobody knew about. Two bodies and one live pilgrim come out of the stalks on their own. |
| 6 | The smoke fills the tunnel first. Anybody inside is blind and choking before the fire reaches them. Heavily obscured, and a creature that ends its turn in there makes a DC 13 Constitution saving throw or takes 3 (1d6) poison damage from the smoke. |
| 7 | It burns out at the roots and stays standing. Dead in eight rounds, upright for years. The ring becomes a landmark, and the party has just put a permanent thing on the map that other people will steer by. |
| 8 | Green wood, and it barely takes. A rain-fat stand does not want to burn. One torch is nothing. It takes oil, or a spell, or twenty minutes of patient work by somebody who is not currently being drunk. |
| 9 | The fire spreads outward instead of inward. Dry scrub for a hundred yards in every direction, and the party's own camp is in it. The plant is the least of anyone's problems for the next ten minutes. |
| 10 | It turns out there were two. The second stand is forty feet away and its ring was hidden by the first. The fire reaches it, it opens, and now everybody is looking the wrong way. |
| 11 | It burns beautifully and the pool boils. Actually boils, for the better part of an hour, and the steam is the first clean shade anybody has stood in for six days. Bitterly funny and entirely useless. |
| 12 | Whoever lit it is still holding the torch in a three-foot tunnel. The character who solved the problem is now the character in the worst position in the encounter, and they did it to themselves on purpose. Give them the save, and give them the moment. |
Somebody whose entire trade is knowing where water is turns around and walks away from this one, in the open, where everybody can see it. It is a thing that happens, not a thing described.
Jorunn Calder · the water-finder who walks ahead of caravans reading the ground
Wants. To be believed the first time, so that nobody has to be right about it afterwards
Voice. Flat, unhurried, allergic to argument. Points, names the thing once, and waits
Line. “So did he.”
She read a stand as dead and it was not. It was the one that had just eaten and had gone slack and quiet with it, which is row 2 and row 6 of the table above and is the only failure mode her trade has. She lost a boy who was walking behind her and she has never worked ahead of children since. She will not tell the party this. She will tell them not to trust a thirstthorn that looks tired, and she will not explain why, and a character who asks a second time gets told to go and find their own water.
This whole page is a Creature Keeper: one file, offline, no account, yours to keep. Drop it into Gnasher's Grimoire, the free Dungeon Master companion at longislanddungeonmaster.com/grimoire, and the thorn, both tables and the witness land on your shelf beside everything else you run from.
Compatible with fifth edition. Portions derived from the System Reference Document 5.1, © Wizards of the Coast LLC, licensed under Creative Commons Attribution 4.0 International (CC-BY-4.0). Thirstthorn and Jorunn Calder are original content © Long Island Dungeon Master, free to use at your table.
Free, offline, and yours to keep. If this file was passed to you, you can pick up your own copy and the rest of them for nothing: this Keeper's own page · more free Keepers · Gnasher's Grimoire, the free app that runs them.
Auto-built from every data-dc, data-hp, stat block, preset clock and pre-loaded combatant in this file. Prints on its own sheet.
| ? | show / hide this overlay |
| r | roll a d20 (honors adv/dis) |
| n | next turn in the tracker |
| t | open / close DM Tools |
| p | Player Mode on / off |
| 1 to 9 | jump to scene |
| Esc | close drawer / overlay |