How to run False Hydra in your DnD Campaign (stat blocks included!)

Everything you need to run the most terrifying homebrew monster on the internet.

In 2014, Goblin Punch wrote a truly terrifying blog article and introduced the world to the false hydra. You can check it out (his article is more of a tone poem and includes no stat blocks or specific gameplay situations) but it sparked an online craze amongst DM's. In short a false hydra is a many headed, ghost-like boss monster that eats humans alive and preys on unsuspecting villages. But unlike traditional monsters, it messes with memory. Anyone who hears a false hydra forgets they ever saw it, and forgets its victims as well...making it extremely hard to find and kill. It also makes it a very difficult monster to run correctly. Whereas a dragon or giant might just crash into the town killing everyone, to run the false hydra correctly you will need to plan carefully. In this article we'll lay out all of the steps to prepare for running a false hydra in your own campaign, as well as stat blocks for the false hydra at different ages in its life cycle, and a few other helpful stat blocks that will add flavor to the storyline. If you want to watch our video guide, you can find it here!

The Hook

There are two quest hooks you can use to easily start a false hydra scenario:

1. A quiet town on the road...

This works very well for parties that are wandering or exploring. They come across a town that was strangely not on any of their maps, or was left out of their guide's description of the landscape. It appears just like any other town, quiet and serene, but almost entirely forgotten by everyone else in the region. It's very important that the party is not an urgent mission to get somewhere else. A good false hydra may take multiple sessions to defeat, and it may have such an impact on your party that it completely derails them from a larger quest.

2. A letter from an old friend...

This works well for parties that have gone on many adventures together. They receive a letter from an old friend, someone they know reasonably well, but unexplainably in the middle of a sentence there is an abrupt interruption in the writing. A hastily scrawled "help me for the love of god help me" before returning to the normal writing. The players may reasonably want to go and investigate. When they get to the town, they discover things are not as they remember them. The population seems greatly decreased, some familiar faces are no longer there, and their friend has strange gaps in his memory, unable to remember his own spouse or child.

What does a false hydra do?

A false hydra starts as a small cancerous growth, a polyp deep in the earth, and grows larger each time it hears a lie. Some traders of the occult and dangerous have discovered and captured these polyps, and sell them for a very high price (for fun we made a full stat block for it at this age, in case you want to ever want your players to stumble across one). In most cases, it grows larger over the course of many years, until it is strong enough to grow a single head and begin to feed. False hydras in this young stage normally take up residence in pits, basements, tunnels, wells, or other protected subterranean areas. From here they begin to sing. The false hydras song is an enchantment that causes anyone who hears it to forget about the false hydra and its victims. It uses this song to make itself practically invisible to its prey. Their minds refuse to see or recognize the hydra, until it has already sunk its teeth into them. Once devoured, the false hydra knows the memories of its victims, and weaves these into its song. A wife who's husband has gone missing suddenly finds they have no memory of why there are men's clothes in the bureau or boots at the door. Little by little the false hydra grows stronger, growing more heads so its song can travel further through town, until it devours the population in its entirety.

Describing the effects of a false hydra

Describing the effect a false hydra has on a town is the most difficult but most important part! This is where you will need to prepare most as a DM. To make your job easier, we have included a flow for you to follow below.

When you first enter the town, you may notice...

• The town has a church, but no church bell rings. If the players ask about it, no one seems to have noticed. The town has never had someone to toll the bells...despite the bells looking new and well polished. The players see a daily religious ceremony, but there is no cleric. The townsfolk sit happily in the pews and listen to nothing. When asked how the service was, they speak glowingly of their love for the church.
• There is a shop in town full of rotting food and dusty merchandise, but no one seems to notice. When you try to speak to someone about the shop they don't know what you're talking about.
• A wagon without a rider, left in the middle of the street.
• Posters for a beloved mayor, but the mayor's home is empty. No one mentions the mayor, or seems to notice the posters.
• A statue to a local hero, but everyone has forgotten their name and what they were famous for.

After only a few minutes in the town...

The PC's start forgetting these anomalies. For example, if one player notices the empty wagon, they might go to tell another player in the party. But when they do so, interrupt them and say: "You don't remember the wagon anymore. It has completely disappeared from your mind." In most cases as a GM you would never tell your player flat out what they can or can't do, but this is key to the false hydra story working! Prepare yourself for a dramatic moment at the table! Players may gasp, act shocked, be furious - we promise it will be fun. Playing the false hydra does of course demand some things from your players. They are going to have to play their characters as knowing one thing, while they as players know another. Rather than being afraid of this, just lean in! It's okay if they players get frustrated, laugh, metagame just a little bit etc. All of this will just make the poor players feel like they are deeply conflicted and struggling with a mental illusion. To run false hydra correctly you will likely need to remind your players many times what they can and can't remember, so take notes! Jump in frequently to say things like "that person you spoke with you can't remember anymore" or a more fun way to do it is just to draw attention to the details around you "when you go downstairs you are surprised to find breakfast on the table and a cloak hanging on the door: someone has been here!" In reality that 'someone' is the innkeeper, who was captured by the false hydra some hours ago.

The false hydra and 'split limbs'

A very cool idea introduced in the false hydra lore is that parts of your body may rebel against the false hydra's song, while your brain does not. This means your hand may move of its own accord, pointing to where the false hydra is leering through the window, or your feet may drag you to the town well, or your fingers may tear at your skin to scrawl out a clue in blood. All of these are terrifying moments of psychological horror that can add immediate stakes. To help you role-play this situation, we've also included a false limb stat block below.

How to run the hydra's song correctly

As you will see at the stat blocks at the bottom, the hydra's song is an actual ability that can be avoided with a saving throw. However, we recommend when first encountering the false hydra that you assume the players have failed their first number of rolls, until they are actively hunting for the hydra. Having your players make constant saving throws is a great way to ruin the mystery at the beginning of a false hydra story. As soon as they start to suspect that a monster is about, it may be appropriate to slip into saving throws. The CR is very high, meaning that even skilled players will only succeed in some situations, where they suddenly see a glimpse of the hydra itself, or are cascaded with memories of a victim that everyone else has forgotten.

How to kill a false hydra

One of the most satisfying things about false hydra's is they are extremely difficult to kill. There is not 'officially' a strategy to hunting and killing the monster, and your players will need to be creative. Once they start hunting for the hydra, there are a few things you should be doing to maximize your player's experience.

The GM should...

• Know where the false hydra is at all times. It may be helpful to have a mini map of the town and move the hydra from spot to spot throughout the hours, days, or weeks. This will not only allow you to have it realistically kill off the townsfolk one by one, but it means you know when to activate the hydra's powers. Remember, the hydra likes to stay concealed, so it may be moving through sewers or underground tunnels!
• Make the players roll to resist the song when they are within range. Once the hunt for the false hydra has begun, there will be a fun sense of "we're getting closer!" when suddenlt everyone has to make saving throws, putting all the players on high alert.
• Have the false hydra actively killing townsfolk and growing. As you'll see in the stat blocks below, the false hydra is a ticking time bomb that eventually grows so large it becomes almost undefeatable. The players should feel this fear as the townsfolk disappear one by one. If they hide or leave, the town will be consumed, it is just a matter of time.
• Have the false hydra attack a player. This is a very good suggestion if they players are having trouble finding it or staying on task. Don't forget that at any time the false hydra can stop targeting townsfolk and target the players instead! Just be aware that its hit points are purposefully kind of low and AC is weak, so have it attack isolated players or when the party splits.

What the players might do to hunt and kill the false hydra

Here are a few tactics they might explore:

• The players may try area effect spells and activities and hope for sheer luck. For example swinging around a giant rope with a weight on the end, or casting spells that hit a large area, or even just running around shooting arrows. The chances of this working are very slim, but the effects will be fun to play out in the town! This is one reason why knowing where the false hydra is at all times will be key. If a player does manage to hit the false hydra with something, if they have failed their throw against the song, they will likely immediately forget what just happened - but an observing player will see them flailing awkwardly against nothing!
• They may try to see the false hydra in a mirror. According to the original false hydra lore, the false hydra's song cannot make you forget its reflection, just the actual sight of it.
• They may hunt for it in dungeons, wells, or cellars. This can lead to a fun little dungeon crawl with high stakes! Consider having them find the remains of victims or perhaps a badly wounded victim who survived.
• They may try to bait the false hydra. Technically baiting the false hydra is probably the best way to defeat it. When the false hydra is eating, it cannot sing, meaning it becomes visible to everyone around it. Of course then you have to decide someone to use as bait...

Defeating a false hydra

If the players manage to find the hydra, it is highly possible they can kill it! False hydra's are hard to beat because they are hard to find, but in combat, they are pretty soft. Defeating a false hydra can become a satisfying session all on its own. The false hydra's spell will be disspelled, leaving survivors suddenly wracked with torment and guilt over lost loved ones and how quickly they moved on from them. Parts of the town that were forgotten may be in shambles, the economy barely stumbling along, and confusion and anger may run rampant. False hydra's are psychological horror. If you are not running the deep effects they have on a mind and a community, you are missing out on what makes running a false hydra so terrifying.

What if the false hydra wins?

False hydras are not like mindflayers or beholders. They do not have master plans. The only thing they want to do it eat and eat and eat and eat. A false hydra that succeeds in destroying a full village or city will grow larger, becoming a legendary false hydra. You can find this stat block below. They sprout their full seven heads and enter into their final form, a towering monster that wanders the countryside looking for the next town. False hydras of this size are much less stealthy - they can be seen from afar before their song is heard, as great lumbering beasts on the horizon with leering heads. When they arrive in a town they may decide to simply freeze the villagers in place and consume them on the spot, massacring a whole town in the course of a few hours before following the few fleeing survivors to the next settlement on the map. False hydras of this scale become nation destroying bosses. Your players will of course want to fight and defeat it, and to oblige that, we have included a truly massive stat block below. As with all things in running a false hydra, the monster itself is not as important as how it effects the people around it! Consider how a legendary false hydra will destabilize the government, leave a power vacuum for raiders and villains, leave homes abandoned for thieves to loot and mercenaries to pillage for weaponry. Think about the fear it will spread, the wandering caravans of refugees, the defenses a large city may try to build, or hide outs in the mountains or on distant islands that suddenly pop up in response. On a practical level, false hydras can be killed by starving them. An organized nation may be able to move people around quickly and effectively enough to stop it from eating, killing it in a matter of weeks. But we know how often nations or organized...

Stat blocks for the false hydra in 5e

We hope you enjoy running your own false hydra game! Below are the stat blocks we use to run ours. We hope you find them helpful, and we wish your players luck! They are going to need it.