D&D isn’t choosy; it appropriates basically every monster that has ever been referenced anywhere in ANY lore and then adds to that confused jumble a bunch of original monsters that just can’t seem to go away from previous editions. Thus, as a DM when you want to throw some kind of monstrous humanoid at your party, you have a massive list to choose from. Some DMs solve this problem by only having a couple different types of monstrous humanoids in their game, such as just goblins and orcs. I believe this is a sign of weakness and poor breeding. It is much more fun to handpick the monstrous humanoid you want to use based on the exact type of encounter you want to facilitate, both in tactics and theme. Below I list several monstrous humanoids and give a short description of them, common ways I tend to use them, and a specific example of how I have used them in my campaign world:
- Short Description: Simple, straightforward, and violent.
- Uses: Raiders in dangerous areas and minions of powerful villains.
- Example from my Campaign: A band of Orcs led by a powerful Oni inhabited the Flaming Marsh, attacking all who traveled through its lands.
- Short Description: Sneaky (goblins), militaristic (hobgoblins), strong (bugbears), and generally numerous.
- Uses: Military force bent on taking over the world or inhabitants hiding in crumbling ruins clinging to memories of an ancient empire.
- Example from my Campaign: Goblins reside in the Rusty Ruins, which they overwhelmed hundreds of years ago, hiding beneath the earth and in ruined structures, ambushing those foolish enough to disturb them.
- Short Description: Clever, zealous, encountered in hordes.
- Uses: Protectors of Dragons lairs, mostly!
- Example from my Campaign: Malifas, an ancient and powerful dragon, has a group of devoted kobolds who worship him and protect his lair with deadly traps.
- Short Description: Insane, demonic, utterly without fear.
- Uses: A plague of destruction sweeping through civilized lands or as minions to powerful demons!
- Example from my Campaign: Gnolls led by a powerful Immolith swept through villages and towns, burning them to the ground and leaving no survivors.
- Short Description: Alien, mysterious, and amoral.
- Uses: Good for slavers or mercenaries who would be hired out by powerful villains.
- Example from my Campaign: A group of lizardfolk slavers captured children and sold them to a powerful mindflayer.
- Short Description: Creepy, vicious, marine creatures.
- Uses: As raiders at Sea!
- Example from my Campaign: Sahuagin specially adapted to the extreme temperatures of the Boilding Sea raid merchant ships for food and valuables.
- Short Description: Pathetic monstrosities that should be wiped off the face of the earth.
- Uses: Good low level nuisances to show that an area has truly suffered hard times if these creatures are allowed to exist within its boundaries. Disheartening to encounter but a joy to kill.
- Example from my Campaign: Bullywugs inhabit the Inkroot swamps, which is home to several struggling villages, a wretched reminder that the area is no longer safe. They are a danger to travelers and woodsmen and hunters who stray too far from the safety of their villages.