Black Dragon, Blue Dragon, Green Dragon, Red Dragon, White Dragon, Beholders, Aboleths, Liches, Vampires, Tarrasques.
One head can snap a bite
Two heads means you must give flight
Three heads is a monstrous sight
Four heads will make you quiver with fright
Five heads will eat your noble knight
Setting the necks alight
Is the only way to end the hydras plight
If you were to ask someone to make a list of monsters, there is a very good chance that one of the monsters they will remember is the dreaded hydra. A monster of mythic proportions this beast has captivated our imagination since the tale of Heracles slaying the great horror was spread across the Greek countryside. The hydra lives on to this day as a fearsome creature unable to be slain by time. Join me as I discuss how you can use a hydra in your D&D campaign to terrorize your party of adventurers.
The Mind of the Belligerent
Hydras are a well-known monster and pretending that they are mysterious creatures doesn’t do you any good when your players already know to bring tar, oil, and torches. Their weakness to fire should be something even the daftest peasant would understand. After all, a hydra is very simple. If you cut off its head two more grow in its place, but this can be stopped with fire. But this simplicity in its design shouldn’t prevent it from being a terrifying monster capable of tearing a party apart in seconds.
Hydras can actually be a really cool part of worldbuilding if you allow the general population to understand these creatures. Hydras in traditional mythology have been used as tests of strength for great warriors, and the same can be said of your D&D world. This can even lead to interesting story beats as the party hears tales of a hydra devouring a town and then have to deal with the same hydra after some plucky wannabe hero ended up giving it three more heads.
Hydras are not intelligent creatures but they will understand their weaknesses better than anyone. Fire is one of the only things that can threaten a hydra so they will already know to be careful around anyone carrying a torch. Fortunately one of the greatest answers to fire also coincides with where hydras tend to lair. The monster manual gives hydras a swim speed and the ability to hold their breath for up to an hour. If your party believes they are prepared for a hydra and saunter up to its lair expecting an easy challenge, surprise them by dragging one of the members underwater drowning them and make the wizard regret preparing Fireball instead of Water Breathing. By switching each of its regular attacks for a grapple, pulling someone under the surface of the water should be effortless.
A hydra can be summed up by two things. Its heads, and its unending hunger. Hydras will eat anything in their path to the point where they sometimes would rather die than give up on a meal. This ceaseless hunger is the primary motivation behind everything a hydra does and makes them especially dangerous if they ever cross paths with the party. Whereas many monsters may respect the party and give them space a hydra only knows that it must eat. No matter what the party is doing, whether it be setting up camp, fighting another powerful foe, or traveling with a huge group, if they are in hydra territory they better be prepared for a hydra to crash whatever is happening.
For those who have been cornered by a hydra, retreat is not an option. As soon as a hydra gets within melee range each of its heads has a chance to perform an opportunity attack which does the same amount of damage as a round of simply attacking. A hydra will also never give up the chase if it knows it has a chance to get a meal. Hydras may seem slow, but they can be blindingly fast if they are committed to the hunt. If a hydra takes its turn to dash towards its victim it can cover a staggering 60 feet in a turn and then threaten to lash out with all of its heads if they so much as take a step back.
The hydra doesn’t care if it is harmed when chasing down prey. In fact, it wants to trigger as many opportunity attacks as it can because it grows new heads at the end of its turn, which doesn’t give the wizard that the hydra has cornered a chance to fire off a Firebolt in time. If they haven’t taken enough damage to trigger growing a head have the hydra bite one of its own heads off to grow a new one. Hydras are one of the most aggressive creatures in the game and no matter how much the players have learned about the hydra beforehand, they should still not be prepared when it smashes into them and breaks their formation.
Lair of the Myth
Hydras don’t have a consistent lair that they stay in for very long. Because of their neverending hunger, they are forced to move onto new lands after they devour the top of the food chain. Even though they end up being quite nomadic as a result of this they still tend to keep similar lairs. One of the most important components for a hydras lair is water. This tends to have hydras living in swamps, marshes, near lakes and rivers, or in a cave by the ocean.
While hydras don’t have regional effects the surrounding environment will be greatly disturbed by the presence of the hydra. The food chain will be disrupted and entire towns will have to leave if they get wind of a hydras presence. Ghost towns will litter the area in a five-mile radius around a hydra with only the very brave and the very stupid refusing to leave. The mayor of a ghost town may even ask the players to kill the hydra that has taken lair in his mansion, but on the condition that they don’t burn the town to the ground trying to kill it.
Hydras have remained a facet of literature for thousands of years and have achieved a legendary status because of it. Even though they only boast a challenge rating of 8 in the monster manual, this doesn’t mean that they are any less deserving of their title. Hydras are uniquely aggressive creatures that have well-known weaknesses and could be your player’s first experience of beast outwitting man. If your players are resourceful, they’ll be able to overcome the challenge and will have successfully become heroes. But the transition from zero to hero has to be a challenge or else your players won’t feel like they earned it.
The first shriek shook the trees. The second made the birds flee. The third made the heroes freeze. A long emerald neck snaked its way through the branches, its frosted fangs stained with butchery. More heads crept in with all of the eyes centered on the newfound prey. The remnants of their friend could be found shared between all the jaws. It roared again, knowing there was more to its feast. The hydra was still hungry.