They live in your skin. Or your organ meat. Or your eyeballs. They grow there and then, in a bloody and horrific display, burrow their way out. Disgusting. Instinct: To infect

• Burrow under flesh
• Lay eggs
• Burst forth from an infected creature

Evolutionary happenstance has created a clever underground predator. Disguised as a rocky formation—most often a stalactite or stalagmite—the roper waits for its prey to wander by. When it does, whether it’s a rat, a goblin or a foolhardy adventurer, a mass of thin, whipping tentacles erupts from the thing’s hide. A hundred lashes in the blink of an eye and the stunned prey is being dragged into the roper’s mouth. Surprisingly effective for a thing that looks like a rock. Instinct: To ambush

• Ensnare the unsuspecting
• Disarm a foe
• Chew on someone

Iä! Iä! The Purple Worm! Blessed is its holy slime! We walk, unworthy, in its miles of massive tunnels. We are but shadows under its violet and all-consuming glory. Mere acolytes, we who hope someday to return to the great embrace of its tooth-ringed maw. Let it consume us! Let it eat our homes and villages so that we might be taken! Iä! Iä! The Purple Worm! Instinct: To consume

• Swallow whole
• Tunnel through stone and earth

The gods that made this thing were playing some sick joke on the civilized folk of the world. The maggot-squid wields a face full of horrible squirming tentacles that, if they touch you, feel like being struck by lightning. They’ll paralyze you and chew you up slowly while you’re helpless. Best to not let it get to that. Instinct: To eat

• Paralyze with a touch

The mating call of the otyugh is a horrible, blaring cry that sounds like a cross between an elephant dying and an over-eager vulture. The otyugh spends much of its time partly submerged in filthy water and prefers eating garbage over any other food. As a result, it often grows fat and strong on the offal of orcs, goblins and other cave-dwelling sub-humans. Get too close, however, and you’ll have one of its barbed tentacles dragging you into that soggy, razor-toothed maw. If you get away with your life, best get to a doctor, or your victory may be short lived. Instinct: To befoul

• Infect someone with filth fever
• Fling someone or something

They dwell beneath the earth because they do not belong above it any longer. An undying race of mighty titans fled the plains and mountains in ages past—driven out by men and their heroes. Left to bide their time in the dark, hate and anger warmed by the pools of lava deep below. It’s said that an earthquake is a goliath’s birthing cry. Someday they’ll take back what’s theirs. Instinct: To retake

• Shake the earth
• Retreat, only to come back stronger

Oh lord, who taught them magic? Instinct: To tap power beyond their stature

• Unleash a poorly understood spell
• Pour forth magical chaos
• Use other goblins for shields

Nobody seems to know where these things came from. Elves say they’re the dwarves’ fault—dredged up from a hidden place beneath the earth. Dwarves say they’re bad elvish children, taken away at birth and raised in the dark. The truth of the matter is that goblins have always been here and they’ll be here once all the civilized races have fallen and gone away. Goblins never die out. There’s just too damn many of them. Instinct: To multiply

• Charge!
• Call more goblins
• Retreat and return with (many) more

How many adventurers’ last thoughts were “strange, this tunnel seems cleaner than most?” Too many, and all because of this transparent menace. A great acidic blob that expands to fill a small chamber or corridor and then slides, ever so slowly along, eating everything in its path. It cannot eat stone or metal and will often have them floating in its jelly mass. Blech. Instinct: To clean

• Fill an apparently empty space
• Dissolve

It’s a sad thing, really. Guardians bred by magi of the past with no more castles to guard. Their ancestors’ sacred task bred into their blood leads them to find a place—ruins mostly, but sometimes a cave or hill or mountain cliff—and guard it as though their masters yet lived below. They’re notoriously good at finding valuables buried below the earth, though. Find one of these winged reptiles and you’ll find yourself a treasure nearby. Just be careful, they’re hard to spot and tend to move in packs. Instinct: To guard

• Attack with the element of surprise
• Take to the air
• Blend into stonework