Invidious

The Giant Bombadier Beetle Riders of Gracklstugh

Deep in the Underdark, where madness festers and the air hums with the whispers of forgotten gods, the Derro—twisted, blue-skinned humanoids driven by paranoia and cruelty—have tamed a creature as volatile as their own minds: the Giant Bombardier Beetle. These hulking insects, grown monstrous in the dark caverns, scuttle through tunnels on six clacking legs, their glossy black carapaces streaked with veins of sickly yellow. At a glance, they’re a nightmare of chitin and menace, stretching eight feet long and standing waist-high to a human, with mandibles that snap like steel traps. But it’s the acrid stench wafting from their swollen abdomens that truly warns of their danger—a promise of the scalding, noxious spray they unleash when provoked.

The Derro didn’t domesticate these beasts out of patience or skill; they broke them with sheer insanity. Legends among the deep-dwellers say the first Derro beetle-tamers were savants, sorcerers whose fractured minds resonated with the beetles’ primal fury. They lured the creatures with heaps of rotting flesh—carrion scavenged from failed raids—and bound them with chains forged in mad rituals to their god Diirinka, the patron of deceit and stolen magic. Now, the Derro ride these beetles into battle, cackling atop crude saddles lashed to the insects’ backs, their crossbows and hooked spears gleaming with poison. The beetles aren’t just mounts; they’re living weapons, their chemical blasts turning cramped tunnels into choking killzones.

To the Derro, the Giant Bombardier Beetle is more than a tool—it’s a symbol of their warped genius. They call them “Diirinka’s Spitters,” believing each scalding spray is a gift from their deity, a blessing to burn away their enemies and their own endless fears. Other Underdark races—duergar, drow, even the mind flayers—give these mounted lunatics a wide berth, knowing the Derro’s recklessness makes them as likely to blow themselves up as their foes. And yet, the beetles endure, their armored bodies shrugging off blows as they charge, driven by hunger and the Derro’s relentless prodding. In the dark, where sanity is a luxury, the Giant Bombardier Beetle and its rider are a perfect, terrible match.

In the heart of the Underdark, where the air grows thick with heat and the clang of hammers echoes through stone, lies Gracklstugh, the City of Blades. This sprawling Duergar stronghold squats beside a vast, subterranean lake called the Darklake, its waters black and still, reflecting the glow of molten forges like a mirror of night. The city’s gray stone walls rise jagged and unyielding, bristling with spiked turrets and choked with the smoke of smithies that never sleep. Duergar, dour and relentless, toil here, their grim faces streaked with soot as they craft weapons of war and whisper of betrayal in shadowed alleys. But Gracklstugh isn’t theirs alone—lurking in its underbelly, festering in the cracks of this iron-clad order, are the Derro, a seething tide of paranoia and spite.

The Derro claim no grand district in Gracklstugh; they infest its fringes, squatting in crumbling warrens carved into the city’s outer walls or beneath its docks, where the Darklake’s damp seeps through stone. Their presence is a thorn in the Duergar’s side—tolerated only because the Derro’s madness occasionally births brilliance, and their Giant Bombardier Beetles bring a reckless edge to Gracklstugh’s defenses. These blue-skinned lunatics scurry through the streets, hauling chains and rancid meat to feed their mounts, their high-pitched cackles clashing with the Duergar’s dour grunts. The beetles clack alongside them, mandibles snapping at anything that strays too close, their yellow-streaked shells glinting in the forge-light as they drag crude sledges piled with scavenged junk or fresh kills.

Beyond the city’s walls, the Derro’s true territory unfurls—a sprawling fungal jungle that stretches into the tunnels west of Gracklstugh, fed by the heat and mineral-rich runoff of the Darklake. Here, the air hums with spores and the sickly-sweet stink of decay. Towering mushrooms, some as tall as trees, glow with bioluminescent veins of purple and green, their caps drooping under the weight of parasitic vines that drip viscous sap. The ground is a spongy morass, littered with the husks of lesser insects and the bones of unwary travelers, picked clean by the Derro’s beetles. These “Diirinka’s Spitters” roam freely when not saddled, their clawed legs tearing through the undergrowth as they hunt, their acidic sprays sizzling through fungal stalks to flush out prey. The Derro patrol this jungle atop their mounts, crossbows cocked and spears poised, shrieking battle cries to their god as they chase down intruders or rival clans.

At the jungle’s edge, where the mushrooms thin and the air grows sharp with sulfur, lies a scalding spring—a bubbling, steaming pool that spills from a cavern wall into a massive chamber beyond. The spring’s heat is unbearable, its waters laced with corrosive minerals that sting the lungs and blister the skin. Past its banks, the cavern opens into a surreal, jagged expanse, carved by centuries of acid rain that falls from fissures in the ceiling high above. The rain hisses as it strikes the stone, eating away at it to form towering, needle-like peaks that gleam with wet, eroded edges, and deep crevices that plunge into shadow. The floor is a pitted maze of pools and sharp ridges, the air thick with a caustic mist that burns the eyes and coats the tongue with a metallic tang.

This cavern is a crucible of faerzress—the wild, radiant magic that pulses through the Underdark’s depths. Its shimmering, violet glow seeps from the stone, bathing the peaks and pooling in the crevices, a raw energy that warps flesh and twists life. It’s here, in this hostile womb, that the Giant Bombardier Beetles mutated and evolved. The faerzress supercharged their glands, turning a natural defense into a weapon of war—their sprays grew hotter, more potent, their shells thicker to withstand the acid’s bite. The Derro see this place as sacred, a gift from Diirinka, and they raid it for beetle larvae, dragging the wriggling grubs back to Gracklstugh to raise in captivity. The cavern’s edges, where the acid rain thins, mark a natural barrier—keeping the fungal jungle at bay, its spores unable to take root in the corrosive ground.

The Derro beetle riders rule this borderland with frenzied pride. They charge through the jungle on their mounts, spraying foes and fleeing into the cavern’s crevices when pressed, daring enemies to follow where the acid rain and faerzress await. The Duergar of Gracklstugh watch warily, knowing the Derro’s territory is both a shield and a liability—a buffer against invaders, but a powder keg of chaos that could one day turn inward. In this corner of the Underdark, where steel meets madness and nature bends to magic, the Giant Bombardier Beetle and its riders thrive, a volatile symphony of destruction echoing through the dark.