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Menaces in the Muck - Swamp and River Creatures for D&D 5E - Banner - Resized 2

An NPC and 7 swamp creatures and elementals, with stat blocks for use in D&D 5E.

Tall reeds and grasses, stinking muck, and the white noise of flowing water and buzzing insects all help to cover the movement of the swamp’s creatures. Beasts and monstrosities lurk, unabated by the putrid air and sinking mud, hunting the unwary and uninformed. Only the creatures that are built to survive are able to. Anyone else would be a fool to set foot in their domain. 

The River Jetty

Three ramshackle buildings are connected by wooden walkways, raised on stilts above the mud and muck of the marshy shore. While they are still standing, the structures tell a long story of damage and repairs, with areas of differently-aged wood where it has rotted and then been replaced. The boardwalks that run between them continue into a T-shaped jetty a short way over the water. A small rowboat and a larger log platform bob gently, secured by ropes. Smoke rises from one chimney, tinging the humid, grime-soaked air with the smell of a meal being prepared. The sound of clattering movement from inside the same building seems to confirm that someone is home.

Few would dare make their home on the side of the river but, fortunately for those seeking to cross, there is one who has. Julien Cormier lives in seclusion on the riverside. The three shacks function as his home, boathouse and workshop, and storage shed. He also maintains a barge service as an addition to his own boats and fishing, as a way to opportunistically barter with the few visitors that he receives.

Julien Cormier

(N male elf scout)

A scowling, hunched elven man with sun-withered skin and in working leathers that appear almost as old as the man himself. One eye flicks to you from below a furrowed brow and tangle of grey hair, the other remaining lazily in place. He gives you a smile of stained teeth, coughs his throat clear, and motions a hand in greeting.

Julien Cormier is a private but not unfriendly resident of the swamp, who chooses to exist in isolation on the side of the river. His life before the swamp is his own secret. He has lived there for many decades, surviving off of the land and only interacting with others when they find themselves on his property. When travelers and adventurers do arrive at his door, Julien is more than happy to share a meal and regale them with various, questionable tales of his own adventurous youth.

In addition to conversation, Julien also capitalizes on his visitors and unique position by offering temporary accommodation and river crossings. The former involves hammocks strung throughout the packed interior of his storage warehouse, above and between the mountains of crates, knickknacks, and other treasures that he has hoarded over the years. His barge service is accomplished with a simple platform of logs with which he can ferry people across the expansive river.

Importantly, Julien’s life leaves him with no need or desire for gold. He instead asks that his customers barter for his services. A night in the warehouse, including one meal, costs the equivalent of 5 sp per person, while a trip across the river equates to 2 gp per passenger, but these must be paid in items or favors that would interest Julien. Characters may be able to convince him of the value of something he may otherwise be uninterested in, of course. They may even be able to negotiate for other services, such as guidance through the swamp.

For those that purchase a barge crossing or similar service, Julien is sure to note that the river is dangerous and that he will be of no help against anything that might appear. There is no price that would make him break this rule. Does he simply refuse to endanger himself? Perhaps he has a better understanding of how to deal with the wildlife? Or is he keeping to the terms of a mutual non-aggression pact with a nearby green hag or swamp behir? Julien’s reasons are his own.

Maps and Assets Downloads

In addition to the River Jetty, we have a variety of other swamp, jungle, and marsh battle maps and assets that are perfect for our swamp creatures. We even have a handbook of 20 jungle encounters which can pit the characters against them…

Swamp and River Creatures

Swamp ecosystems are diverse, delicate, and dangerous. Creatures of varying sizes and temperaments cover every inch of the landscape, from the treetops to the deepest riverbeds, drowning the environment in the sounds of their calls and cries. And these creatures are not limited to the mundane. At the top of the food chain are the fantastical monstrosities, lycanthropes, and other esoteric beings that stalk the swamp, few of which are accommodating of outsiders stomping through their land.

Swamp Behir

A long, serpentine shape slides effortlessly across the muck, propelled by six pairs of clawed legs. The creature’s almost fish-like body appears at least as thick as you are tall, and far longer. Its skin is a dark, mottled brown. Thick whiskers protrude from around a wide, fang-filled mouth that draws in silent breaths, inflating two sacs below its neck. Its skin bristles and the creature’s color fades to match its muddy surroundings.

Like their cavern counterparts, swamp behirs are reclusive and uncooperative monstrosities that dominate their chosen environments. Their ferocity and intelligence easily elevate them to the status of apex predators, often even above any humanoid occupants. Unlike regular behirs, the swamp behir prefers to hunt in the rivers and reeds of its home. It nestles itself into the mud of a shoreline or lake bed, adjusting the color of its skin to match, and watching and waiting for unwary meals to approach. Once prey appears, the behir strikes first with a cloud of poisonous breath. This disables the hunter’s target and begins the digestion process, usually moments before the behir swallows its victim whole.

Swamp behirs rely less on their lairs than other behirs. Their camouflage and penchant for patience see them spending long periods of time motionless in their environment as they hunt. They do maintain lairs, however, with entrances hidden within bodies of water. These may be at the bottom of lakes or rivers, or the behir may even construct a pool over the tunnel into its home. This passage then loops back up into the behir’s lair. These distinctive, seemingly bottomless pools are known to many who live near swamps, and are always taken as a terror-inducing sign for one to move as far from that spot as they can, as quickly and quietly as they can.

The swamp behir is a behir modified to resemble several regular animals that might live in the same habitat. Its appearance and lair are based on catfish, while its frog-like poison sacs are used to indicate the change from being a lightning-based creature to one that deals poison damage. Its Venom Breath deals less damage than the original Lightning Breath but is able to poison targets and deal further damage if they fail their saving throws. The behir’s camouflage was a result of it originally being designed to look like a chameleon, but was kept as a way for it to hunt in the swamps and separate it from the base behir.


The crocodile’s head lifts, supported not by the long body and stumpy limbs you were expecting, but rather a hulking humanoid body with thick, muscular arms and legs. It wears loosely draped skins that resemble local animals, with several leather pouches and a spear that it raises in its hands. Behind it, a massive tail carves a channel in the mud. Two slitted yellow eyes turn and inspect you as it lumbers forward.

Lycanthropes vary greatly depending on where they are found and where those who are afflicted pass on their curse. Often drawn to the native lands of their bestial side, or fleeing from discovery or the danger they themselves pose, some may find their way to the forest, deserts, or even to swamps. 

Werecrocodile monster token

The latter environment is favored by the werecrocodile. Powerful and solitary, werecrocodiles are able to easily hunt and survive without the need for civilization, which results in their minds drifting further towards the animalistic. This can lead to them becoming territorial and violently unwelcoming towards other people, though there are tales of isolated peoples with traditions of venerating werecrocodiles as their protectors and leaders. One should still make every effort to avoid them, particularly given the werecrocodile’s propensity for attacking with its cursed bite.

As one might expect, the werecrocodile is a simple combination of the werebear and crocodile creatures. The werebear was the perfect basis for a large, dangerous lycanthrope, which was given the actions and aquatic capabilities of the latter, as well as the giant crocodile’s Tail attack in place of claws.


A rotund, mostly human body with pockmarked, green and brown skin and the head of a toad. It lifts a gnarled wooden club in both of its hands, blinking slowly and giving off a loud croak, as its skin begins to exude a glistening liquid. The same drips from its wide mouth. A bitter smell reaches your nose as the creature adjusts its powerful legs, preparing to move.

Lacking much of the violent, chaotic outbursts of the werecrocodile and other lycanthropes, weretoads primarily seek to be undisturbed. They are not territorial but will attack if threatened. This does not make them any less dangerous if they are to transform in a populated area, as anyone that strays too close may be attacked. As such, many find their way to quiet swamps and wetlands in search of peaceful isolation. Their less dominant other half allows some weretoads to live almost regular lives on the edges of these locales, disappearing into the uninhabited expanses when their transformation calls for it.

Weretoad monster token

The weretoad is built from a wereboar and given abilities from both the giant frog and giant toad. Its Poison Spit is modeled on a guardian naga’s, while the weretoad’s Slick Skin gives it some final unique flavor as well as allowing it to maintain its movement in combat.

Siren Ghost

Looking down, you see the swirling shades of green that hang in the water move gently. They part and push against a form that isn’t there, a triangle of three patches darkening into the shapes of a stretched mouth and deep, vacant eyes. The rest of a translucent humanoid coalesces behind them, rushing towards you.

The stories of sirens and other alluring spirits are not limited to oceans. People who live near the deepest and most treacherous swamps often tell tales of seeing shapes in the water and hearing the cries of the drowned. They talk of faces that appear and entrance the unprepared, drawing victims into the water to share their fate. Little more is known about these ‘siren ghosts’, as details vary depending on who is telling the story, though one warning remains constant: if you see the faces in the water, it’s already too late.

Siren Ghost monster token

Inspired by The Lord of the Rings’ Dead Marshes, the siren ghost was created as a creature that characters would be told stories of before venturing into a swamp. It builds on the ghost creature by swapping its Possession for abilities that draw victims into the water and drown them, while avoiding the usual ‘fish-woman sitting on a rock’ stereotype. The ghost’s Alluring Visage, based on the original Horrifying Visage and the dryad’s Fey Charm, draws victims into the water before it stunning them with its Death’s Kiss and then continues to attack.

Don’t forget your rules for drowning! Characters that are drawn into the water by a siren ghost will take a breath before diving in but will still be on a time limit, in addition to the damage they’re taking. The ghosts may even leave a stunned target to drown in order to charm and attack others.

Bark Mephit

The sound of snapping branches draws your attention to the trees, where a shape rustles free from its camouflage. A small, imp-like creature of bark and leaves cranes its neck and flexes two wings. Twigs grow from its back and arms like jagged spines. You briefly lose track of it as it drops from its perch, before its wings flare out and it catches itself in the air.

Bark mephits are lesser plant elementals and one of several mephit variations comprised of earth and water, alongside their sludge counterparts. They are uncaringly violent and territorial. Often found in large swarms, bark mephits will rarely leave their camouflaged perches except to viciously swoop at anything that strays too close to the trees where they make their homes.

Their abilities and aggressive temperament make bark mephits ideal sentries for hags, who may fill the treetops around their coven with flocks of mephits. The elementals attack anything but the hag, either killing their victim or creating enough commotion to attract more attackers. Should someone reach the hag, her scream can draw every mephit in the area down upon them.

As with most elemental variants, the bark mephit is designed to resemble the element it embodies. Bard and wood were chosen over more vibrant plant life to avoid overlapping with the restraining and poisoning abilities of existing mephits and our own sludge mephit. Instead, the bark mephit was built from the ice mephit. Its Innate Spellcasting is traded for an upgrade to its recharging action, made to resemble a smaller version of the spike growth spell. Its AC was also increased to 14 to similarly reflect barkskin.

Sludge Mephit

The rising sludge begins to separate into the shape of a thin, winged creature with a pointed face and long, slack arms. Its features roil and move as gases bubble and burst from its surface. You see shards of wood, plants, and even bones decaying within the creature’s oily, black body. Its wings stretch out as it heaves itself free of the grime, moving more quickly despite the dripping weight of its own form.

Similar in many ways to their bark cousins, the sludge mephit is comprised of the decaying, rotting swamp floor. They are driven by a hunger to consume, spending their time wandering the landscape and feeding on plants, animals, and any other refuse they can find. The rapid digestion of such a varied diet fills the mephit with bubbles of toxic gas. They can then make use of this in their attacks, strategically venting the gases to poison their prey. The gases’ flammability does, unfortunately, also give the mephit a volatile, vengeful weakness.

When summoned by hags, the sludge mephits are often let loose in a swamp. Their constant consumption and the resulting gases and sludge can slowly sap a location of its habitability, giving the hag greater dominion. When called on, they also make for effective hunters and guards.

The sludge mephit was originally the same creature as the bark mephit, before separating them to allow for more distinct abilities and design. It was built from the magma mephit, with appropriate changes to its resistances, vulnerabilities, innate spell, and recharging action. The addition to its Death Burst is given to embody the sludge’s flammable gases and further differentiate the mephit from its counterparts.


What first appears to be a mud-soaked child instead seems to be entirely comprised of grime and other swamp refuse, molded in the shape of a small humanoid. Its features are almost frog-like, with webbed fingers and fins across its limbs, bulbous, yellow-green eyes, and a wide mouth with rows of randomly angled teeth. Bubbles inflate and recede along its neck and sternum, occasionally popping and releasing a sickly green gas.

Small but numerous elementals formed of the sludge and decaying filth of the marsh, muckmins are most often summoned to serve as scavengers and hunters for hags. They share the energetic, often violent curiosity of magmins. This makes them ideal minions for a hag exerting her power over an area, with the added bonus of returning to their ‘mother’ with anything interesting that they may find. The muckmins also serve as a wonderfully potent deterrence against any adventurers encroaching on the hag’s territory.

Magmins are a personal favorite creature due to their mischievous chaos, perfect fit as minions, and ability to force a party to quickly adjust their tactics. As elementals, they can also be drastically changed by simply swapping their element to another; in this case, from fire to acid. This does make it important to add other minor abilities and alterations to set them apart, hence the addition of the muckmin’s Stench in place of Ignited Illumination. For its regular Touch attack, rather than setting targets ablaze, the muckmin grapples them with the adhesive sludge of its body.

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Looking for more, similar creatures? Check out the fungal creatures and their tokens in our ‘Mushrooms, Moss, and Monsters’, right here!

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About the author

Troy McConnell

Part-time DM and author of 2-Minute Tabletop's encounters, map lore, and characters. Basically, I write about all the campaign ideas that I don't have time to run. All with the assistance of my feline familiar, Wink.

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