How To Homebrew Your Own Monsters for DnD 5e – Full Guide

Last Updated on February 9, 2023

From huge compendiums like the Monster Manual and Monsters of the Multiverse to setting books and individual adventures, Dungeons & Dragons 5e is absolutely overflowing with monsters of almost every conceivable variety. Whether you’re looking for classic goblins, orcs, ogres, a shapeshifting ooze monster, world-eating space leviathans, or just a very angry garden gnome, D&D 5e has got you covered. 

But, what if the monster you want to put in your next D&D 5e campaign doesn’t exist in D&D? 

Well, strap on your best goggles and raise the lightning rod, Dr. Frankenstein; we’re going to make a monster. 

How Do You Homebrew Monsters in DnD 5e? 

There are three main ways to create a new monster for your D&D 5e campaign: reskin an existing monster, modify an existing monster’s stats and/or give it new abilities, or build a new creature from scratch. 

Before we get started, however, I should probably say that I’m of the opinion that the section devoted to creating new monsters in the D&D 5e Dungeon Master’s Guide is a huge disservice to game masters everywhere. 

The chapter gives a lot of very detailed advice on how to balance your homebrewed creations so that they’re not too high or low CR for your players’ characters to handle. Personally, I don’t think that sort of box-ticking is particularly fun, and it’s certainly not what compels us as dungeon masters to lovingly handcraft our very own nightmarish abominations to torment our players. 

If you want meticulously balanced monsters that politely refrain from exceeding the PCs’ power level, go read the Dungeon Master’s Guide (chapter 9). If you want actionable, (hopefully) useful advice on how to homebrew monsters that you can use at your next session based on how I approach homebrewing monsters, keep reading. 

Reskinning an Existing Monster 

The simplest way to “create” a new monster for your game is to just grab the stat block for an existing monster and change the way you describe it to your players. This is an entirely cosmetic process, and mechanically the monster will be exactly the same.  

Your players don’t have to know that the mass of writhing, inky-black tentacles gliding out of the pit to envelop them is actually just a Giant Constrictor Snake. You still end up with a powerful grappling monster with a slow movement speed. 

Likewise, they don’t need to know that the brutish, slow-witted boxer who fights for the local street gang is actually just a Bear. Or that the goblins’ killer mutant pigs that they’ve been breeding in the forest are actually… Bears. Who does it hurt if the Rogue Orb of Telekinetic Violence that escaped the wizard’s laboratory, coated itself in chunks of bone, viscera, metal, and masonry, and is rampaging through the lab is actually (once more for the people at the back) a Bear? 

To steal a very good piece of advice from Jack Guignol, just use bears. 

So much of what the players will imagine in the moment and remember afterward will involve their own abilities and actions. Whether the monster used a grapple attack or two claw attacks is of secondary concern. Unless you think a mechanic, spell, or ability is absolutely essential to the way your new monster feels and functions, keep it simple. Stick with a bear. 

Remixing an Existing Monster 

This is probably the most common way that people make homebrew monsters for their campaigns. It’s certainly how I do it. 

Remixing an existing monster to give it new abilities, strengths, and weaknesses is a tried-and-tested process in D&D (and, like, game design in general). In fact, D&D’s monster manuals are full of official monsters that started out in life as homebrewed variations on existing creatures. Just look at the Lich’s offshoots, the Demilich and the Alhoon, or the Beholder’s diminutive kin, the Gazer and the Beholder Zombie. 

There are two main ways to remix an existing monster.

The Variant

One of the best ways to flex your homebrewing muscles (not to mention inject a bit of variety into a campaign) is to create a variant on an existing creature. 

To do this, take the base creature’s stat block and think about ways to alter it. 

For example, you could create subspecies of penguin aarakocra that swim rather than fly. Just replace the aarakocra’s flying speed with a swimming speed, and maybe rework their Dive Attack into something more like a breaching attack; if they swim for up to 30 feet, they can use their action to jump out of the water up to 10 feet and deal additional damage. Maybe give them harpoons that let them drag enemies into the freezing water after they hit them with a ranged attack. 

Alternatively, you could bolt additional abilities onto an existing creature. For example, you could make wild magic goblins that became dangerously charged with arcane energy after eating too much of the refuse in the alley behind a wizard’s tower. 

Cosmetically, the goblins just glow and vibrate and smell really weird. Mechanically, if a goblin dies (or gets surprised, or angry, or whatever you want — maybe it’s different for each goblin), there should be a chance that you have to roll on the wild magic surge table. It’s a relatively small change, but it could have big consequences. 

The Reskinned Remix   

The other way to tackle remixing a monster is to keep the creature’s base stats, but instead of making it a variant of the original, it becomes a wholly unique monster. Add or subtract abilities to match your concept and distinguish the new creature mechanically from the original. 

For example, I wanted to make a riff on the Japanese nine-tailed fox, the Kitsune. I knew I wanted a highly magical, probably fey, trickery, and wish-granting creature, so I started with the stat block for a Pixie. By removing the flying speed (give it a 40 feet walking speed) and adding the ability to speak common, you’ve got a pretty good Japanese trickster fox.   

Contrary to what I said before about not worrying too much about CR, you do want to make sure to keep an eye on whether you’re massively increasing (or decreasing) the power of a monster by changing its abilities, resistances, etc. It’s fine if you are; just don’t let it surprise you on the first turn of combat. 

Building a Monster From Scratch in DnD 5e 

If you just can’t find the right starter template for a new D&D 5e monster, you can always start from scratch, setting the creature’s Hit Points, AC, Hit Dice, Ability Scores, Proficiency Bonus, Skills, Languages, and so on. 

If you want some decent rough guidelines for setting monster difficulty, the Dungeon Master’s Guide has a list of monster characteristics by CR. This is by no means to be taken as gospel, but it can still be a good way of getting in the right ballpark to challenge your players without an unintentional TPK. 

In addition to all this number crunching, here are my top three tips or guiding principles to help homebrew the best possible monsters. 

Broadcast Its Abilities

Nobody likes a surprise Death Saving throw. Monsters that can hit the PCs with abrupt and unexpected attacks they can’t prepare for aren’t fun. They’re about as good a time as the old “walk down corridor, make a dex save, take 1d10 piercing damage from freakishly well-concealed spike trap,” uh, trap. 

Monsters with special abilities should project that both in their appearance and how they affect their surroundings. An acid-spitting snake should melt trees and patches of stones (not to mention the unrecognizable bodies of its victims) wherever it goes. When the PCs find it, its mouth should be wreathed in noxious fumes, and its scales should be an almost luminous green. 

Obviously, if you’re making a shapeshifter or other super-stealthy creature, you’ll need to foreshadow its abilities in different ways. 

Hit Points or AC, Not Both 

Turns can take quite a long time in D&D 5e. Player characters are complicated, there might be as many as six of them (personally, I kind of hate running or playing in groups bigger than three or four at a push), and then all the monsters need to go. If a player steps up to take their turn for the first time in 15 minutes, rolls, and misses, that’s a bummer. 

I’m a fan of bumping all monster hit points by about 20% and reducing AC by 2-4. It means the PCs hit more often and get to feel like they’re making a difference without the fight actually being much quicker. When I make a homebrewed monster, I like to stick to this ratio. If you do make a monster that’s hard to hit (because they’re really, really heavily armored or super nimble), I want to make sure that they’ll go down once the PCs land a few good hits. 

The very worst thing you can do is make a monster with buckets of hp and a high armor class. Your fights will be long and boring, and your players will not enjoy themselves. Much better to have the monster seem to die and then do a Dark Souls/Mario surprise second form. Or have its mother show up. 

Keep It Simple 

As I said before, D&D 5e is a complicated game. As a DM, you’re going to have a lot to keep track of when you sit down at the table to play. When you make a homebrewed monster or villain, it can be tempting to give it tons of abilities, spells, and cool stuff to do. I urge you, at least in the beginning, to resist. 

A simple monster with one, two, or maaaybe three unique abilities to draw on (preferably ones that do different stuff, like something offensive, something defensive, and something weird) is going to be a lot easier to run at the table, which means you’ll be able to think more tactically and probably do a better job of challenging your players. 

Anyway, that’s all from me on Homebrewing Monsters for DnD 5e. Do you agree with me about the Dungeon Master’s Guide having very little good information on this subject? What do you always try to keep in mind when homebrewing monsters for your campaigns? Am I a complete idiot who just doesn’t understand simple mathematics? Let us know in the comments below. 

Until next time, happy adventuring.