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Alphacada 9

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by

Dale
in

Original Life Forms Referenced:

  • Class Malacostraca: Tiger Pistol Shrimp (Alpheus bellulus)
  • Class Aves: Sword-billed Hummingbird (Ensifera ensifera)
  • Class Reptilia: Alligator Snapping Turtle (Macrochelys temminckii)
  • Class Insecta: Periodical Cicada (Magicicada genus)

Appearance: The Alphacada 9 has the core body of a massive alligator snapping turtle, with a thick, spiky, dome-shaped carapace that looks like a moss-covered boulder. It has four stout, reptilian legs. However, its front right leg is replaced by the hugely oversized, asymmetrical snapping claw of a pistol shrimp, while the front left is a smaller, articulated manipulator claw. Its head is that of a snapping turtle, with a powerful, hooked beak and ancient eyes. Extending from this beak is a bizarre, needle-thin proboscis, longer than the creature’s entire body, like that of a sword-billed hummingbird. Folded neatly against its carapace are four large, transparent, membranous wings, exactly like those of a cicada, which seem far too delicate for its bulky frame.

Size: This is a heavy, dense creature. The carapace of a mature Alphacada 9 typically measures 4 to 5 feet in diameter. With its head extended, it is low to the ground, but its long proboscis can reach over 6 feet. They weigh between 300 and 500 pounds, with most of that weight being their shell and powerful snapping claw.

Speed: The Alphacada 9 is exceptionally slow. On land, it has a ponderous, lumbering gait. It cannot chase anything. Its wings are incapable of true flight due to its immense weight; however, it can beat them at incredible speeds to create a disorienting drone or to achieve a sudden, jarring, hummingbird-like sideways “hop” of a few feet to reposition itself during an attack.

Stat Modifiers:

  • Strength: High
  • Perception: Average
  • Intellect: Low (Instinct-driven)
  • Agility: Very Low
  • Charisma: Very Low
  • Endurance: Very High

Skills: The creature is a master of Stealth when motionless in water or mud. Its primary skill is Ambush, relying on its natural camouflage and patience. It also possesses a unique Sonic Manipulation skill, capable of producing two distinct, powerful sound-based effects.

Behavior: The Alphacada 9 is the embodiment of patience. It is a semi-aquatic ambush predator that will submerge itself in a shallow, murky river or pond, leaving only its head slightly exposed. It can remain perfectly motionless for days, appearing as just another rock. To attract smaller prey like fish or birds, it opens its powerful beak and wiggles a small, worm-like lure on its tongue. For larger targets, it employs a different tactic: it begins to vibrate its delicate wings at high frequency, producing an incredibly loud, deafening, and disorienting drone that can confuse and panic creatures near the water’s edge. Once a target is close and disoriented, it strikes with either its devastating bite or a stunning blast from its sonic claw.

Diet: This creature is an opportunistic omnivore. Its primary feeding method is using its long, needle-like proboscis to pierce and drink nutrient-rich fluids. This can be the nectar of giant bog-flowers, the sap of ancient trees, or, more horrifyingly, the blood of animals it has incapacitated. It also uses its powerful snapping turtle beak to consume flesh, crushing bone and shell to eat fish, large birds, and any mammals or avatars that venture too close to its lair.

Emotions: The Alphacada 9 is almost entirely devoid of recognizable emotion. It operates on a simple, primal loop of dormancy, hunger, and territorial defense. It is defined by a profound, unthinking patience that can be mistaken for non-existence. It only displays aggression when its ambush is triggered or its territory is directly threatened.

Environment Where Found: It is found exclusively in freshwater environments with slow-moving or stagnant water. Murky riverbeds, muddy swamps, large ponds, and the edges of serene lakes are its ideal habitat. It requires water deep enough to submerge its body and a soft, muddy bottom to conceal itself in.

Tags: Ambush Predator, Heavily Armored, Aquatic, Sonic Weapon, Stun Attack, Lure, Feral, Patient Hunter, Omnivore, Slow-Mover, Bioluminescent (the tongue lure), Territorial, Chimeric, Cavitation Claw, Crushing Jaws, Drone Wings, Needle Proboscis, Sanguivore

Age: The Alphacada 9 possesses a remarkably long lifespan, a benefit of its low-energy lifestyle and nigh-impenetrable defenses. They can live for over 150 years, with a life cycle centered around immense patience.

  • Egg: The life cycle begins in a clutch of 10-20 small, stone-like eggs laid in a hidden underwater nest. The eggs are heavy and coated in a gritty mucus that makes them look identical to river rocks.
  • Nymph: The hatchling is a soft-shelled aquatic nymph, spending its first few years hiding in the mud and silt at the bottom of its waterway. It feeds on algae and detritus, molting its shell periodically as it grows. Its sonic and proboscis abilities are undeveloped at this stage.
  • Juvenile: After about a decade, the juvenile Alphacada’s shell has hardened enough for it to begin hunting. It is roughly the size of a large dog and practices its ambush techniques on fish and small animals. Its sonic drone is weak, more of a loud buzz than a deafening roar.
  • Adult: An Alphacada reaches maturity after 25 to 30 years. Now at its full size, its sonic abilities are fully developed, and its beak and claw possess their full crushing power. It will claim a single stretch of river or a pond as its permanent territory, where it may remain for the rest of its life.
  • Ancient: An individual that has survived for over a century is considered an Ancient. Its shell is a massive, moss-covered landscape, often mistaken for a natural geological feature. Its sonic drone can be felt as a tremor in the ground for miles, and its patience is so profound it can enter states of hibernation that last for years.

Mating: Mating for the Alphacada 9 is a rare, powerful, and incredibly loud event. While mostly solitary, they are driven by a primal, cyclical instinct tied to their cicada heritage.

  • The Sonic Summons: Once every decade or so, during the hottest months of the year, mature Alphacadas will crawl onto the banks of their rivers and begin to vibrate their wings. This produces a deafening, resonant drone that travels for immense distances, calling all others of its kind to a specific gathering point.
  • The Convergence: Over several weeks, individuals from all over the region will slowly and ponderously travel towards the source of the loudest drone, creating a temporary and dangerous concentration of these creatures.
  • The Courtship of Power: Mating is a communal affair where males (or the more aggressive individuals) compete. They do not fight directly but engage in a contest of sonic power. They unleash stunning blasts from their cavitation claws into the water and attempt to out-drone each other with their wings. The individuals who can withstand the sonic onslaught and produce the most powerful drone earn the right to mate.
  • Dispersal: After the frantic mating season, the creatures disperse, returning to their solitary lives. The females will later find a secluded spot in their own territory to lay their clutch of eggs, providing no further parental care.

Tactics: The Alphacada 9 is a creature of singular, perfected strategy, relying on patience and overwhelming localized force.

  • The Living Boulder Ambush: Its primary tactic is to submerge itself in shallow, murky water, with only the top of its mossy carapace visible. It becomes indistinguishable from a river rock and can wait in this state for weeks, conserving energy.
  • The Tongue Lure: To draw in smaller, curious prey like large fish, birds, or small mammals, it will open its powerful beak just slightly underwater and wiggle the small, fleshy, worm-like appendage on its tongue. The subtle movement is often irresistible to a hungry animal.
  • Deafening Disorientation: For larger or more intelligent prey, it uses sonic warfare. Before revealing itself, it will begin its cicada-like drone. The sound, amplified by the water, becomes a painful, disorienting wave of pressure that can cause panic and confusion, making targets less likely to notice the “boulder” they are standing near.
  • Stun and Crush: Its attack is a brutal one-two combination. It first unleashes a short-range, high-pressure sonic blast from its pistol shrimp claw, stunning and incapacitating its chosen target. Immediately following this, it lunges with its powerful snapping turtle jaws to deliver a single, devastatingly crushing bite.

Actions: In a combat scenario, an Alphacada 9 can perform several distinct actions:

  • Crushing Jaws: A melee attack with its powerful beak, capable of snapping bones or shattering shields.
  • Cavitation Snap (Rechargeable): Unleashes a 15-foot cone of sonic force from its large claw. Creatures in the area must make a difficult Endurance or Constitution save or be stunned for one round.
  • Deafening Drone: The creature uses its action to begin vibrating its wings. This creates a large aura of painful sound. Any creature that starts its turn in the aura must make a save or suffer penalties to their actions and may become deafened.
  • Proboscis Drain: This attack can only be made against a helpless, grappled, or incapacitated creature. It automatically hits and drains a significant amount of life force, healing the Alphacada.
  • Wing Hop: As a bonus action, the creature can use a powerful burst from its wings to launch itself 5-10 feet in any direction, a jarring and sudden movement that does not provoke opportunity attacks.

Other Interesting Information

  • The Shell as an Ecosystem: The shells of ancient Alphacadas often become hosts to unique, symbiotic life. Rare mosses, alchemical fungi, and even small, magical plants can be found growing in the shell’s crevices. Harvesting these ingredients may be a quest in itself, requiring adventurers to approach the dormant creature without waking it.
  • The Hummingbird’s Task: Legends persist in some swamp-dwelling cultures of giant, ancient flowers that only bloom once a century and whose nectar holds miraculous properties. These flowers are so deep that only the incredibly long proboscis of an Alphacada can pollinate them. A druid or herbalist might seek to lure or guide one of these creatures to perform this vital task.
  • Acoustic Geology: The repeated, powerful snaps of the creature’s cavitation claw over its long lifetime can have a profound effect on its environment. The shockwaves can fracture riverbeds, widen underwater caves, and weaken cliff faces. The lair of an Ancient is often a shattered landscape of its own making.
  • Blood Siphon: While it can eat solid food, its preferred method of feeding is to use its long, needle-like proboscis to siphon nutrient-rich fluids. This is most often the blood of creatures it has stunned or killed, but it has also been observed using it to drink the sap of ancient, magical trees.

An encounter with the ponderous yet deadly Alphacada 9 is almost never a matter of tracking it down. Instead, adventurers typically find themselves facing one because they have been hired for a highly specialized task, have trespassed into its territory by mistake, or because the creature itself has become an immovable, sonic menace.

The Specialist’s Request: A Quest for Unique Components

The bizarre chimera of biological parts that makes up an Alphacada 9 is a treasure trove for artisans and scholars who are brave enough to seek it out. This leads to very specific, high-risk, high-reward contracts.

  • The Sonic Engineer’s Blueprint: The creature’s pistol shrimp claw, capable of creating a stunning cavitation bubble, is a marvel of natural engineering. An artificer or engineer might hire a party to get close to a live Alphacada and take magical readings of the claw as it activates. An even more dangerous quest would involve retrieving the claw intact so it can be studied and reverse-engineered to create sonic mining tools or non-lethal city guard weaponry.
  • The Bard’s Magnum Opus: The unique resonant frequency of the Alphacada’s cicada wings is said to be one of the most powerful and pure tones in the natural world. A master instrument maker or a college of bards might commission a party to acquire a set of undamaged wings from a mature specimen, hoping to study their structure to build a one-of-a-kind organ or enchanted horn capable of replicating the sound.
  • The Herbalist’s Pollinator: Legend tells of ancient, giant swamp lilies whose nectar can cure magical diseases, but their flowers are too deep for any normal insect or bird to pollinate. Only the impossibly long, needle-like proboscis of an Alphacada can reach the core of the flower. A desperate herbalist or alchemist might hire adventurers not to slay the beast, but to perform the incredibly delicate task of luring or nudging the territorial monster towards the flower to ensure its pollination, so that its healing nectar can be produced.

The Unwitting Intrusion: Wrong Place, Wrong Time

The most common way to meet an Alphacada 9 is to not realize you have met it at all, until it is too late. Its mastery of ambush makes accidental encounters particularly deadly.

  • The Living Rock: A party traveling through a swamp may decide to make camp on what appears to be a large, stable, mossy boulder half-submerged in the water. They might rest against it or tie their raft to it. The encounter begins when the “boulder” shifts, and a massive snapping turtle head emerges from the water next to their campfire.
  • The Siren’s Drone: While navigating a murky river, the adventurers suddenly hear a low hum that rapidly escalates into a deafening, physically painful drone. The sound disorients them, causing them to lose control of their vessel, which drifts into the shallows right next to the source of the noise—a territorial Alphacada using its cicada wings to drive prey into its kill zone.
  • The Lure: An adventurer with a keen eye might spot something wriggling in the mouth of what looks like a submerged dragon turtle skull. Thinking it an easy meal or a strange fish, they approach, only to realize the “skull” is the open beak of the Alphacada, and they have fallen for its tongue-lure.

The Territorial Menace: An Immovable Obstacle

While a single Alphacada is sedentary, its choice of home can turn it from a reclusive animal into a major problem that only powerful adventurers can solve.

  • The Toll Keeper of the River: An Alphacada has established its territory in a stretch of river that is vital for a local village’s fishing and trade. Any boat that attempts to pass is either stunned and sunk by its sonic claw or its occupants are lured to the shore by its disorienting drone. The villagers, facing starvation or isolation, would pool their life’s savings to hire a party to slay the “River Devil.”
  • The Cicada Cycle: A rare, periodic event occurs where dozens of Alphacadas mature simultaneously and converge on a single wetland for a month-long mating season. Their combined sonic drone is catastrophic, shattering trees, causing landslides, driving other wildlife mad, and being audible for miles. A regional governor would issue an emergency decree, hiring any available adventurers to break up the gathering before it permanently destroys the entire ecosystem.
  • The Guardian of the Bridge: A construction guild has been hired to build a bridge over a gorge, but a massive, ancient Alphacada lives directly below the construction site. Its intermittent sonic blasts have damaged pylons and its intimidating presence has caused workers to flee. The party would be hired as “security,” tasked with eliminating the creature so that progress can resume.

Beyond the more obvious materials like its carapace and sonic claw, a skilled harvester can procure a number of unique and powerful reagents from the corpse of an Alphacada 9, owing to its bizarre chimeric anatomy.

  • Resonant Tymbal Membranes Located at the base of the creature’s cicada wings are the tymbal organs it uses to create its deafening drone. These twin membranes are incredibly thin yet durable, and they vibrate at a perfect, magically-attuned frequency. When carefully harvested and stretched over a drum or the body of a stringed instrument, they can be used to create powerful bardic instruments capable of projecting sound over immense distances or creating disorienting, low-frequency waves in combat.
  • Bioluminescent Tongue Lure The small, wriggling, worm-like appendage on the creature’s tongue is a self-contained bioluminescent organ. If extracted carefully, the gland at its base can be ground into a paste to create potent alchemical lures for fishing or trapping other monsters. In enchanting, the entire preserved lure can be set into an amulet or helmet, where it can be commanded to glow and wriggle, serving as a powerful focus for spells of hypnotism, suggestion, and fascination.
  • The Cavitation Chamber Inside the creature’s oversized pistol shrimp claw is a unique, hollow nodule of spiraled chitin. This is the chamber that focuses and amplifies the sonic blast. This “Cavitation Chamber” can be removed and used by an artificer as a natural amplifier. When incorporated into a sonic mining tool, it allows for the shattering of rock with greater efficiency. When used as a focus for a magical wand or staff, it can transform simple force spells into concussive blasts that can stun opponents.
  • Proboscis Capillary Filters The interior of the long, needle-like proboscis is not a simple tube, but is instead lined with millions of microscopic, magically-attuned tubules. These act as a perfect biological filter. Alchemists can harvest sections of the proboscis to use in delicate distillation and purification processes, allowing them to separate complex magical potions into their base components with unparalleled precision.
  • Turtle-Lock Jaw Sinew The muscles and sinews that power the creature’s snapping turtle beak are incredibly dense and possess a unique “locking” property that allows it to maintain immense pressure with little effort. This sinew can be harvested and braided into ropes that, when enchanted, can be used to create snares or bindings that are almost impossible to break. Artificers also use the material to craft powerful vises or the gripping hands of golem-like constructs.
  • Metabolic Regulator Heart To manage its extremely slow, patient existence punctuated by bursts of intense sonic energy, the Alphacada has a complex, multi-chambered heart that regulates its metabolism. Consuming a small, prepared portion of this heart can grant a short-term version of its effects, allowing an adventurer to enter a state of metabolic stillness, dramatically slowing their need for air while holding their breath or allowing them to burst into action from a resting state with a bonus to initiative.

Song that Broke the Stone

In the annals of the River-Folk, there is a telling of two brothers. The first was Borin, whose hands were made for the spear and whose voice was a loud boast upon the wind. The second was Elian, whose hands were for the flute and whose voice was seldom heard above a whisper.

In their time, a great stillness fell upon the river. The fish vanished, and the birds flew no more along the banks. In their place came a sound, a low and ceaseless hum that was felt in the bones more than it was heard with the ear. The drone grew over many moons until it became a sickness, a blanket of noise that frayed the nerves and curdled the milk. The elders said it was the river’s heart groaning in sorrow.

But Borin, whose heart was full of a warrior’s fire, declared it was no spirit, but a beast. He pointed to the deep, muddy part of the river where a great, moss-covered stone had appeared, a stone no man remembered seeing before. “There is the creature’s shell!” he proclaimed. “Its hum is a coward’s challenge! I will break this stone and silence its song with my spear!”

Elian, the listener, tried to stay his brother’s hand. “Brother,” he whispered, “I have listened to the drone. It is not a song of war. It is a song of patience. It is the sound of a thing that has not moved for an age, and will not move for an age to come. Your strength cannot fight a thing that is more stone than beast.”

Borin laughed and called Elian’s wisdom fear. He took up his heaviest shield and his sharpest spear and marched to the riverbank, to the place of the Silent Thunder. Elian, his heart a heavy stone in his own breast, followed with naught but his flute of hollowed bone.

As Borin approached the great mossy rock, the hum grew into a physical force. It was a roar that had no mouth, a wave that had no water. The air itself grew thick and heavy. Borin raised his shield, but a shield cannot block a sound. He roared his own challenge, but his voice was swallowed by the drone. He tried to charge, but his legs grew heavy, and his mind grew clouded, and the world swam before his eyes. The great warrior was brought to his knees, his strength a useless thing against the immense, unthinking patience of the sound.

The great rock in the river shifted. A head like that of an ancient turtle, with a beak that could snap ironwood, emerged from the water. It looked upon the fallen warrior with eyes that held no anger, only a cold and ancient hunger.

It was then that Elian, hidden in the reeds, put his flute to his lips. He knew he could not shout down a storm. He knew he could not break a mountain with a song. So he did not try. He listened to the great drone, to its deep and single note, and he played a new sound. He played a note so high and clear it was like a silver needle. He did not play against the drone, but beside it. He wove his small, sharp music through the great, heavy tapestry of the creature’s sound.

The monster, which had not known a new thing in a hundred years, was startled. Its drone was a weapon of singular purpose, and this new sound, this needle of music, was a puzzle it could not solve. The great hum faltered. The crushing pressure in the air lessened. For the first time, the creature’s patient focus was broken as it turned its ancient eyes toward the source of the clear, strange song.

In that moment of distraction, the world grew clear again for Borin. He saw his brother’s wisdom. He saw the creature turn its great head. He saw the soft place of flesh where the neck joined the heavy shell. Humbled, and with a silent thanks to his brother, he put all of his remaining strength into a single, perfect throw. The spear flew true, and struck deep into the creature’s weak point.

There was a terrible, wet sound, and the drone stopped entirely. The beast, wounded and enraged, unleashed a single, thunderous clap from its great claw that sent a shockwave through the water. Then, with a slow and final motion, it slid back beneath the mud and was gone. The river was silent.

Borin came to his brother and did not boast. He took the flute from Elian’s hands and looked at the simple bone instrument that had succeeded where his spear and shield had failed.

The moral of this telling is thus: The loudest roar may be silenced not by a greater roar, but by a single, perfect note. A shield may block a spear, but only wisdom can answer a song.

Suggested conversions to other systems:

Dungeons & Dragons 5th Edition

Sonic Carapace Large monstrosity, unaligned

Armor Class 18 (natural armor) Hit Points 157 (15d10 + 75) Speed 20 ft., swim 30 ft.

STR 19 (+4), DEX 6 (-2), CON 20 (+5), INT 3 (-4), WIS 14 (+2), CHA 5 (-3)

Saving Throws STR +8, CON +9 Damage Resistances Thunder Senses Darkvision 60 ft., Tremorsense 60 ft., Passive Perception 12 Languages — Challenge 9 (5,000 XP) Proficiency Bonus +4

Amphibious. The sonic carapace can breathe air and water.

Living Boulder. While submerged in murky water and motionless, the sonic carapace is indistinguishable from a mossy boulder and has advantage on Dexterity (Stealth) checks.

Siege Monster. The sonic carapace deals double damage to objects and structures.

Actions

Crushing Jaws. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 26 (4d10 + 4) piercing damage. If the target is a creature, it is grappled (escape DC 16).

Cavitation Snap (Recharge 5–6). The sonic carapace unleashes a sonic blast from its large claw in a 15-foot cone. Each creature in that area must make a DC 17 Constitution saving throw. On a failed save, a creature takes 27 (6d8) thunder damage and is stunned until the end of its next turn. On a successful save, the creature takes half as much damage and is not stunned.

Deafening Drone (1/Day). The sonic carapace vibrates its wings, creating a sphere of painful, disorienting sound with a 30-foot radius centered on itself. The drone lasts for 1 minute or until the sonic carapace is incapacitated. Any creature that starts its turn in the area must succeed on a DC 17 Constitution saving throw or take 11 (2d10) thunder damage and be deafened for the duration of the drone.

Proboscis Drain. Melee Weapon Attack: +8 to hit, reach 15 ft., one incapacitated or grappled creature. Hit: 10 (2d6 + 4) piercing damage, and the sonic carapace regains hit points equal to the damage dealt.

Call of Cthulhu 7th Edition

Old Moss-Back A legendary horror of the deep swamps, an ancient creature of immense patience and sudden, deafening violence. It is often mistaken for a moss-covered rock by the unwary, an error for which there is no repentance.

Characteristics STR 90, CON 95, SIZ 95, DEX 20, INT 25, POW 70

HP: 19 Damage Bonus: +2d6 Build: 4 (Huge) Move: 3

Attacks Attacks per round: 1 Fighting (Jaws) 75% (37/15), deals 2d10 + damage bonus. Anyone hit by the jaws must make a CON roll or suffer a Major Wound. Special Attack – Sonic Snap: As an attack, Old Moss-Back can snap its great claw. All Investigators within 5 yards must make a Hard CON roll or be stunned, losing their next action from the concussive blast. Special Attack – Maddening Drone: Old Moss-Back can begin a low, thrumming drone. All Investigators who can hear it must make a POW roll each round. On a failure, the drone’s vibrations are so disorienting that the Investigator suffers a penalty die on all actions.

Skills: Stealth (When Submerged) 95%. Armor: 10-point shell. Regular firearms are almost useless, pinging off its hide. Only high-powered rifles, explosives, or other extreme measures can harm it. Spells: None.

Sanity Loss: 1d3/1d8 Sanity points to witness Old Moss-Back reveal itself to be a living creature. 1/1d4 Sanity points to be subjected to its Maddening Drone.

Blades in the Dark

The Murk-Engine An ancient, living relic that slumbers in the deepest, most polluted canals of Duskwall or the surrounding marshes. It is less a creature and more a sentient, territorial piece of industrial sound and fury.

Threat Level: 4 (A massive, supernatural force; an environmental hazard)

Description: A colossal turtle-like beast, its shell a landscape of moss, refuse, and decay. It seems entirely dormant until disturbed, at which point it unleashes overwhelming sonic power.

Drives: To remain dormant, to consume any who disturb its slumber, to fill its territory with its maddening sound.

Instinct: To respond to disturbance with overwhelming sonic force.

Moves:

  • Begin the droning hum: Creates a dangerous, maddening area of sound. All characters within earshot suffer 1 stress at the beginning of each scene tick as long as the drone continues.
  • Unleash a stunning crack: A single PC or a small area is the target of a sonic boom from its claw. This inflicts harm (Level 2, “Deafened and Dazed”).
  • A jaw that bites through stone: Its bite attack deals extreme harm (Level 4, “Crushed”) and can destroy parts of the environment (a gondola, a stone wall, a bridge support).
  • Fade back into the landscape: It ceases all activity, becoming dormant and indistinguishable from a mossy rock once more. This ends the immediate confrontation but does not remove the threat.

Knave 2nd Edition

Boom-Shell HD 10; Armor as Plate + Shield (19); Morale 12; Attack Jaws (d12)

Description: A colossal, turtle-like creature with a massive, spiked shell, an oversized claw, and insectile wings. It lies dormant in murky water, looking like a boulder.

Qualities: Patient, Ancient, Deafening.

Reactions (d6): 1-2: Attack with Jaws. 3: Use Stun Clap. 4: Begin Maddening Drone. 5: Submerge and hide. 6: Retreat to a more defensible position.

Special Abilities:

  • Fortress: Non-magical weapons inflict half damage to the Boom-Shell’s tough carapace.
  • Stun Clap: In place of its normal attack, the Boom-Shell can clap its oversized claw. All targets in a 15-foot cone must save versus paralysis or lose their next turn.
  • Maddening Drone: The Boom-Shell can use its turn to begin a powerful drone. All characters within 60 feet who can hear it have a Disadvantage on all attacks and saves. The Boom-Shell must use its turn each round to maintain the drone.
  • Ambush: If it attacks a target that was unaware of it (e.g., mistook it for a rock), its first attack deals double damage.

Fate Core

The Drone That Drowns An ancient, living rock of the deep swamps and forgotten rivers. It is less a creature and more a sentient environmental hazard, whose song is a crushing weight that signifies the end of all other sound.

High Concept: Ancient, Armored Riverbed Predator Trouble: Slow and Ponderous Until Provoked Other Aspects: A Shell Like a Mossy Boulder; The Hum That Shakes Your Bones; A Clap That Stills the Heart

Skills Great (+4): Physique Good (+3): Provoke, Fight Fair (+2): Notice, Stealth (in water) Average (+1): Will

Stunts Impenetrable Shell: Because my shell is like a fortress, when I am submerged and still, I have Armor: 2 against physical attacks. Deafening Drone: Because my sound is overwhelming, I can use Provoke to make a mental attack against all targets in my zone. If I succeed, I don’t inflict stress; instead, I attach the Situation Aspect Deafened and Disoriented to the zone with one free invocation. Cavitation Snap: Once per conflict, I can unleash a sonic blast as a special Fight attack. Anyone who fails their defense is Stunned and cannot take an action on their next exchange.

Stress [1] [2] [3] [4] Consequences Mild (2): Moderate (4): Severe (6):

Numenera & Cypher System

The Lithosonic Guardian A chimerical bio-form that often lies dormant for decades at the bottom of Ninth World rivers and lakes, appearing as a mossy, geological formation. It awakens only to defend its territory with overwhelming sonic force.

Level: 7 Health: 30 Damage: 7 points (from bite) Armor: 4 Movement: Slow; can move through water as its primary movement. Modifications: Stealth as level 9 when submerged and motionless.

Combat: The guardian’s primary attack is its Crushing Bite, which deals 7 points of damage. It can use its Sonic Snap against a target in immediate range. This is a level 7 Intellect-based attack (as it’s a special ability). If it hits, the target takes 4 points of speed damage (as their nervous system is shocked) and is stunned, losing their next turn. It can activate its Deafening Drone. This is a level 6 environmental effect that fills a short range around the creature. Any character who starts their turn in the area must make a Might defense task or take 2 points of ambient damage and find all their actions hindered for that round.

GM Intrusion: The GM can spend 1 XP to have the guardian:

  • Erupt from the riverbed, revealing that the “boulder” a character was standing on is actually the creature’s shell. The character is thrown prone and the guardian gets a free attack.
  • Use its sonic snap with such force that it shatters a cypher or fragile item a character is holding.
  • Use its long proboscis on a stunned character, draining 4 points of Health from them and healing itself for the same amount.
  • Begin its drone at a harmonic frequency that causes nearby ruins or cliffs to become unstable and begin to collapse.

Pathfinder 2nd Edition

River-Thunder Creature 9

N Large Beast Amphibious

Perception +19; Tremorsense (imprecise) 60 feet Languages — Skills Athletics +21, Intimidation +19, Stealth +18 (or +22 in water)

Str +8, Dex +1, Con +6, Int -4, Wis +4, Cha -2

AC 28; Fort +21, Ref +14, Will +17 HP 170

Living Boulder While motionless and fully submerged in murky water, the River-Thunder is undetected unless a creature succeeds at a DC 32 Perception check to Seek it.

Actions

[one-action] Jaws Melee Strike +21, Damage 2d12+11 piercing plus Improved Grab. [one-action] Cavitation Snap The River-Thunder unleashes a 15-foot cone of sonic force. Each creature in the cone takes 8d6 sonic damage (DC 28 basic Fortitude save). A creature that critically fails its save is also stunned 1. The River-Thunder cannot use Cavitation Snap again for 1d4 rounds.

[two-actions] Deafening Drone (auditory, evocation, primal, sonic) The River-Thunder vibrates its wings, creating a 30-foot emanation of sound. Each creature that starts its turn in the area must make a DC 28 Fortitude save. On a failure, it takes 3d6 sonic damage and is deafened for 1 minute. On a critical failure, it takes 6d6 sonic damage and is deafened permanently. The River-Thunder can Sustain this emanation.

[one-action] Proboscis Drain Requirements The River-Thunder has a creature grabbed. It makes a proboscis Strike against the grabbed creature with a +21 attack bonus. On a hit, it deals 2d6+8 piercing damage, and the River-Thunder gains temporary Hit Points equal to the damage dealt.

Savage Worlds Adventure Edition

Swamp-Stomper A hulking, territorial beast of the deep swamps, the Swamp-Stomper is a living fortress of shell and sonic fury. Its arrival is heralded by a low hum that quickly escalates into a deafening drone that can shatter bone and nerve.

Attributes: Agility d4, Smarts d4 (A), Spirit d8, Strength d12+2, Vigor d12 Skills: Athletics d6, Fighting d10, Intimidation d10, Notice d8, Stealth d8 Pace: 3; Parry: 7; Toughness: 15 (6)

Special Abilities:

  • Armor +6: Heavy natural carapace.
  • Aquatic: Pace 4.
  • Bite: Str+d10.
  • Deafening Drone: As an action, the Swamp-Stomper can begin its drone. All characters in a Large Burst Template centered on it must make a Spirit roll at –2. Failure results in being Distracted; critical failure results in being Stunned.
  • Sonic Snap: The Swamp-Stomper uses the Cone Template. Characters in the cone must make a Vigor roll at –2 or be Stunned.
  • Size 5 (Large): Its Strength is considered one die type higher for Encumbrance and Minimum Strength to use items. Its Toughness is increased by 5.
  • Slow: The Swamp-Stomper’s running die is a d4.
  • Lure: The creature can use a Test action against an adjacent target using its Spirit versus their Smarts. If successful, it uses its tongue-lure to mesmerize them.

Shadowrun, 6th World

Boom-Shell A heavily-armored, Awakened paracritter that has become an apex predator in polluted marshlands and corporate arcology reservoirs. Its bizarre combination of abilities makes it a formidable piece of mobile area denial, with some megacorps rumored to be capturing them for use as living security systems.

Attributes Body: 8 Agility: 3 Reaction: 4 Strength: 7 Willpower: 5 Logic: 1 Intuition: 4 Charisma: 1 Edge: 3 Essence: 6.0 Magic: 6

Derived Stats Initiative: 8 + 1d6 Physical Condition Monitor: 12 Stun Condition Monitor: 11 Overflow: 8 Movement: 6/12 (crawl), 8/16 (swim) Armor: 14 (Natural Armor)

Skills Athletics 3, Perception 4, Stealth 5, Unarmed Combat 4

Critter Powers Armor: The creature’s shell provides its natural armor rating. Enhanced Senses: Tremor Sense (20m). Natural Weapon (Beak): Damage Value 9P, AP -3. Disorienting Drone: As a Major Action, the Boom-Shell can begin vibrating its wings. Any character within 20 meters who can hear the drone suffers a -2 dice pool penalty to all actions requiring concentration (including spellcasting, shooting, and technical skills). The Boom-Shell must use a Minor Action each turn to maintain the drone. Sonic Stun: As a Major Action, the Boom-Shell can unleash a concussive blast from its large claw. This is a ranged attack using Agility + Unarmed Combat with a range of 10m. If it hits, it deals 8S damage, and the target must resist knockdown.

Starfinder

Carapace Concussor Creature 9 XP 6,400 N Large magical beast Init +1; Senses Blindsense (vibration) 60 ft.; Perception +17

Defense HP 150 EAC 22; KAC 24 Fort +13; Ref +11; Will +8 Defensive Abilities Fortified Shell; Resistances Sonic 10

Offense Speed 20 ft., swim 30 ft. Melee Crushing Bite +21 (2d10+15 P) Ranged Sonic Stun +18 (causes stunned condition, Fort DC 16) Space 10 ft.; Reach 10 ft. (15 ft. with proboscis) Offensive Abilities Blood Drain Aura Disorienting Drone (30 ft., shaken, Will DC 16 negates)

Statistics STR +6; DEX +1; CON +4; INT -4; WIS +2; CHA -2 Skills Athletics +17, Stealth +22

Ecology Environment Temperate or warm swamps and freshwater bodies Organization Solitary

Special Abilities Blood Drain (Ex) As a full action, the carapace concussor can attempt to drain the blood of a helpless or pinned creature using its proboscis. This is a melee attack that deals 3d6 damage, and the creature regains Hit Points equal to the damage dealt. Disorienting Drone (Su) As a move action, the carapace concussor can activate a sonic drone. Any creature that starts its turn within 30 feet of it must succeed at a DC 16 Will save or be shaken for 1 round. Fortified Shell (Ex) The carapace concussor has Hardness 5. As a standard action, it can retract into its shell, increasing its KAC by 4 and gaining an additional 5 points of Hardness. It cannot move or attack while retracted. Sonic Stun (Ex) As a standard action, the carapace concussor can fire a concussive blast from its large claw at a single target within 30 feet. The target must succeed at a DC 16 Fortitude save or be stunned for 1 round.

Traveller (Mongoose 2nd Edition)

Aquatic Armoured Predator (Alphecada maior) UPP: E4E200 Armor: Heavy Carapace-10 Attacks: Bite (Crush, 4d6) or Sonic Stun (Stun) or Deafening Drone (Disorient) Skills: Stealth-3 (when submerged), Athletics-1 Behavior: Ambush Predator, Omnivore, Territorial.

Description: A large, heavily-armoured amphibious lifeform typically found in the stagnant, murky waters of low-gravity worlds. Its primary body resembles that of a Terran turtle, but it possesses a single, massive asymmetric claw capable of emitting a powerful concussive blast in the water. Its most dangerous feature is a high-frequency drone produced by vestigial wings, capable of disorienting creatures and interfering with electronics over a wide area. It is a patient ambush predator, often lying motionless for days until prey wanders within range. Its long, needle-like proboscis is used for feeding on immobilised targets or siphoning nutrients from giant flora.

Warhammer Fantasy Roleplay, 4th Edition

Mire-Drum A monstrous beast of the deep fens and marshes, the Mire-Drum is considered a dire omen by the river-folk of the Empire. Its approach is heralded by a low, maddening hum that grows into a deafening roar capable of shattering nerves and bone. It is a living siege engine, a walking bastion of shell and sonic fury that is all but impervious to conventional arms.

Mire-Drum Profile WS 55, BS —, S 65, T 70, I 45, Agi 20, Dex —, Int 15, WP 60, Fel 5 Wounds: 42

Traits: Amphibious, Armour (8), Bite (Crushing Jaws) +12, Fear (3), Hardy, Size (Large), Swamp-Strider, Territorial Skills: Perception 60, Stealth (Submerged) 75

Special Abilities: Deafening Drone: As a full action, the Mire-Drum can begin to vibrate its wings. Any character who starts their turn within 12 yards (6 squares) must make a Hard (-20) Endurance Test or gain 1 Stunned Condition. The Mire-Drum must continue to spend a full action each round to maintain this drone. Concussive Clap: Once per combat, as an action, the Mire-Drum may clap its great claw. All characters in a cone-shaped template must make a Difficult (-10) Dodge Test. Those who fail are thrown from their feet, gaining the Prone Condition and suffering a hit with a Damage of 10 that ignores Toughness Bonus but not Armour Points. Impenetrable Shell: The Mire-Drum’s Armour is not subject to the effects of the Ablaze or Acid Conditions. Any attack made against it suffers a -2 SL penalty to determine a Critical Hit.