Epic Encounters

10 Epic Swamp Monsters for a 5e Encounter

So, your RPG adventuring party just stumbled across a swamp. And where there’s a swamp, there are swamp monsters to encounter. 

What enemies will your players find in the rotting vegetation? That’s up to you! Luckily, Jamie Giblin has survived a swamp or two, and gathered some valuable info on swamp creatures in the process. 

Check out this 5e swamp monster list for a selection of things that go squelch in the night...

10 Epic Swamp Monsters for a 5e Encounter

By Jamie Giblin

Swamps are great settings for adventures. They’re teeming with life, home to unusual flora and fauna, and have a food-chain your adventurers can fit into (probably somewhere near the bottom).

Perhaps your players got lost and are now stranded in a boggy area. Maybe they desperately need to make medicine, and the key ingredient is a mysterious plant that only grows in swamps. Or, maybe they’re just passing through to get to the other side.

Whatever reason your party has for being in a swamp, there’s a good chance they’ll encounter a monster or two! I’ve picked my 10 favourite swamp monsters to help inspire you.

Assassin Vines

Challenge Rating: 3

Where better to start a swamp creature list than with semi-sentient vegetation? In a fantasy swamp, even the plants will try to eat you. Assassin vines are a great way to ambush players who haven’t brushed up on their botanical knowledge. 


Challenge Rating: ¼

Great for lower-level adventures, Bullywugs are frog-like humanoids with a reputation for self destruction. To challenge higher level characters, have them attack in a group. 

Bullywugs let you have a little fun as the Games Master (GM), too. Get a kick out of roleplaying these amphibious NPC’s by mixing croaks and gargled common. 

Speaking of speech, Bullywugs are ideal for social/combat encounters where your players can intimidate these cowardly foes.

Giant Frog or Giant Toad

Challenge Rating: ¼ to 1

Looks like adventurers are back on the menu! A staple swamp encounter, the Giant Frog or Giant Toad works great as a main course after a Bullywugs appetiser. You can really throw players off guard by swallowing them whole.

Giant Snake

Challenge Rating: 8 / 13 / 17


There must be something in the swamp water, because here’s another giant creature! Silently slithering, tracking the movements of your party, this monster snake could burst from the undergrowth to strike at any moment. 

Notice the three different challenge ratings? With the stats in this readymade set, you can tailor your Giant Snake encounter to suit the experience level of your party. Whether your party are seasoned adventurers or lower level, slide a Giant Snake battle into your next campaign.


Challenge Rating: ¼ to 5 


Goblins pop up everywhere — even in tree tops! Have them living in trees around the edge of your swamp to introduce aerial action that will frustrate and confound those wearing heavy plate.

Your goblins could even rain down arrows coated in venomous goop made from local tree frogs. Check out these tree goblins for inspiration.


Challenge Rating: 8 / 13 / 20 


This many-headed reptilian horror will ensnare your players in a thicket of snapping jaws. Even more at home in a swamp than a Giant Snake, a Hydra will create its nest in the heart of the wetland and fiercely guard against intruders. 

Like the Giant Snake, the Hydra has three challenge ratings found in its readymade set for players of all levels. Check out the stats, prompts, and story hooks in Swamp of the Hydra and you’ll have a swampy boss fight ready in no time!


Challenge Rating: 1 to 7


Intelligent and cunning, these reptilian humanoids have been around for millennia. So long, in fact, that there’s a good chance you’ll stumble across a Serpentfolk temple deep in a swamp. Listen out for the hiss of druidic chants.

Like Bullywugs, Serpentfolk are another opportunity for your players to exercise their powers of social persuasion. Will the guards let them through, or will they be marked for ritual sacrifice? Check out these Serpentfolk for inspiration to create your encounter.

Spider Tyrant

Challenge Rating: ???


Hmm, failed your investigation check? I guess we’ll have to come back to this entry when we’ve learned a little more about future Epic Encounters...

Swarm of Insects

Challenge Rating: ½ 

If you’ve ever been anywhere near a wetland, you’ll know the importance of bug repellant and suitable clothing. Just writing this has me itchy. 

And that’s the great thing about insect swarms. Not only are they easy to imagine, but they can follow your party wherever they go. They also don't need to come as a full-blown combat encounter. 

Instead, use a swarm of insects to create a travelling encounter that brings your swamp to life, frustrating and distracting your players as they swat the air with unarmed strikes.

Twig Blights

Challenge Rating: ⅛

Twig Blights aren’t much of a challenge, even for a first level party. Still, spending time in a swamp should rarely be comfortable. A savvy GM can use these annoyances to interrupt a short (or long) rest and keep that tension high. Get me out of here!

What’s Your Favourite Swamp Monster?

There are so many 5e swamp creatures to choose from! These are my favourites, but what about yours? Does another monster deserve a place on this list? Let me know on Twitter (@steamforgedgamesltd) by using #EpicEncounters. Otherwise, happy swamp exploring!