The Karthid – The Tideforged of the Black Tides
If you have been following the channel for a bit you would know the direction of the things that Dave and I are working on. My big push right now is building out some great content for Under the 
Dome. This is a post apocalyptic fantasy world. And while this is the first official post for Under the Dome, this post can be used and put anywhere. Feel free to add this location and this monster in any location for your campaign.
Within the lands of Under the Dome the waters are not the open and inviting things of fantasy worlds. Within the post apocalyptic events all lands not under the protection of domes even the seas and lakes can be cruel things. One such locale is listed below:
The Black Tides (A Corrupted, Oil-Slicked Ocean with a Life of Its Own)
“The waves shimmer like ink, and the ships that enter never seem to leave.”
- A dark, oily sea, where the water itself has become a thick, semi-liquid sludge.
- Some areas are so dense that ships can “walk” across the waves.
- Oil-born horrors rise from the depths, sliding across decks, swallowing sailors whole.
- Some whispers claim that the Black Tides are the remains of an ancient, living god, whose blood was spilled across the sea.
🔹 Narrative Hook: A derelict vessel, covered in black slime, has drifted into Balaria’s docks. It is abandoned—except for the whispers coming from its hull.
Inspired by the Crabfolk of D&D I recently picked up from the Seas & Shores line of miniatures a handful of Crabfolk Minis. When I looked at how cool these sculpts were I wanted to add these creatures to my setting but to take my own spin and insert them where they fit best. So without further ado, let me introduce you to The Karthid.
The Karthid – The Tideforged of the Black Tides
“The waves do not bow to the land, nor do we.”
Design Concept – The Karthid (Crabfolk of the Black Tides)
The Karthid are a race of massive, humanoid crustaceans who dwell within the Black Tides, the dark, oil-slicked, semi-liquid ocean filled with horrors and whispers. Unlike most creatures, the Karthid do not fear the corrupted waters—they thrive in them, having evolved alongside its shifting, oil-infused tides.
- Resilient & Heavily Armored: Karthid stand 8-10 feet tall, their thick, chitinous shells covered in hardened black resin, making them nearly impervious to cutting weapons.
- Semi-Aquatic Survivors: While capable of breathing air, they move fastest in water and can walk along the seabed, using their massive claws to anchor themselves in strong currents.
- Symbiotic Relationship with the Tides: Some Karthid exhibit strange, semi-liquid mutations, as if the Black Tides have infused them with unnatural resilience, adaptive biology, or even oil-based magic.
🔹 Best Fit Location: The Black Tides, where ships sink without a trace, and the water itself is thick with sentient oil.
- Their ancient coral cities rise from the depths, but they frequently raid or scavenge shipwrecks, making them feared by sailors and scavengers alike.
- Some believe the Karthid know the secrets of the Black Tides, but no outsider has ever been invited deep enough to confirm.
Karthid Society – Strength Forged by the Tides
Karthid culture values strength, endurance, and resourcefulness, as only the strongest survive the ever-changing tides of their homeland. Their society is structured into three castes, each influenced by how the Black Tides have shaped them.
1. The Shellborne (Warriors & Hunters)
“The land is weak. The sea is strong. We do not fear the weak.”
- The most physically powerful Karthid, their exoskeletons are thicker than steel, and some can regenerate limbs over time.
- Hunt and scavenge from the wrecks of fallen ships, dragging them into the deep for resources.
- Often raid coastal settlements or passing vessels, seeing outsiders as trespassers in their waters.
🔹 Narrative Hook: A Karthid warband has been attacking the coastal trade routes, demanding that “the land-dwellers return what was stolen.” But no one knows what they mean.
2. The Brinecallers (Shamans & Tide-Weavers)
“The Tides whisper, and we listen.”
- Karthid attuned to the voices within the Black Tides, capable of manipulating the semi-liquid waters and calling forth creatures of the deep.
- Some claim to see visions within the tides, interpreting them as messages from ancient beings.
- Their “Tidecasting” magic focuses on corruption, adaptation, and summoning creatures shaped by the sea.
🔹 Narrative Hook: A lone Brinecaller has been found washed up on shore, babbling about an “awakening beneath the waves.” Then the bodies of drowned sailors begin walking again…
3. The Resinborn (Elders & Living Statues of the Deep)
“We have walked these tides for a thousand years. The oil does not take us—it strengthens us.”
- The oldest Karthid, their bodies completely encased in hardened black resin, making them immobile outside of water.
- Serve as the keepers of history and law, only moving when great decisions must be made.
- Some claim they no longer think like mortals, as if they have become one with the tides themselves.
🔹 Narrative Hook: A Resinborn Elder has been taken captive by coastal raiders, but the Karthid refuse to attack, claiming the Elder “is not done dreaming.” What will happen if the Elder awakens?
Karthid Abilities & Traits
The Karthid are not simply large crabs—they are evolved warriors of the tides, with unique biological and magical traits.
1. Chitinous Armor (Trait)
- Reduces all non-magical slashing damage by half due to their hardened exoskeletons.
- Some Karthid can shed and regrow armor, gaining temporary resistance to fire or piercing damage.
2. Crushing Claws (Trait)
- One of their arms is a massive pincer, capable of grappling Large creatures and crushing weapons in half.
- Elite Karthid warriors wield weapons with one hand while using their claws to rip apart enemies.
3. Brinecaller Magic (For Spellcasting Karthid)
- Can summon temporary oil-like tendrils, capable of restraining enemies or pulling ships into the depths.
- Some Brinecallers can “hear” the thoughts of sea creatures, predicting oceanic storms, shipwrecks, or unnatural awakenings.
4. Resinborn Immortality (For Elders & Unique Karthid Leaders)
- Resinborn Karthid do not die of age. Instead, they slowly petrify, becoming immobile but hyper-intelligent.
- If broken free from their resin shells, they return to their prime strength—but at a great cost.
Narrative Hooks & Campaign Integration
The Karthid are not simple monsters—they are a thriving, ancient race that sees the world differently than land-dwellers. Their relationship with the Black Tides makes them powerful allies, deadly enemies, or enigmatic forces whose true goals remain unknown.
- The Drowned Armada – A fleet of shipwrecked vessels has risen from the depths, commanded by Karthid warriors wearing the bones of sailors long dead. What has awakened them?
- The Leviathan Pact – A massive sea-beast has begun destroying Karthid settlements, and the Karthid warlords demand assistance from Balaria’s mages. Will the Gruffs help them—or take advantage of their desperation?
- The Oilborn Prince – A mutated Karthid unlike any before has emerged, its flesh fused with pure Balarium-infused resin. Some claim it is the “chosen one” of the tides, destined to unite the Karthid tribes. Others seek to destroy it before it grows too powerful.
Final Thoughts
The Karthid are more than just crabfolk—they are an entire culture built around survival, honor, and adaptation within a constantly shifting sea. Their unique biology, oil-infused mutations, and spiritual connection to the Black Tides make them a fascinating faction that can serve as allies, antagonists, or something entirely unknown.
Here is an example of a Shellborne to drop in your game, a big jump from the standard CR3 of the crabfolk:
Shellborne Karthid (CR 8)
Large Monstrosity, Lawful Neutral
Stats
- Armor Class: 18 (Natural Armor – Hardened Chitin)
- Hit Points: 136 (13d10+65)
- Speed: 30 ft., Swim 50 ft.
Attributes
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 22 (+6) | 12 (+1) | 20 (+5) | 10 (+0) | 14 (+2) | 10 (+0) |
Saving Throws: Str +10, Con +9
Skills: Athletics +10, Perception +6, Intimidation +5
Damage Resistances: Fire, Cold, Piercing
Damage Immunities: Poison
Condition Immunities: Prone, Charmed, Frightened, Poisoned
Senses: Darkvision 60 ft., Tremorsense 30 ft., Passive Perception 16
Languages: Karthid Sign Language, Deep Speech, Common
Abilities
Hardened Chitin (Trait)
- The Shellborne’s dense, armored exoskeleton reduces incoming slashing and bludgeoning damage from non-magical weapons by half.
- If the Shellborne takes fire or cold damage, its chitin adapts, granting temporary resistance to that type until the end of its next turn.
Crushing Claw (Trait)
- The Shellborne Karthid has one massive pincer, capable of grappling creatures as large as Huge.
- If the Shellborne hits a creature with its claw attack, the target must succeed on a DC 18 Strength saving throw or become grappled (escape DC 18).
- While grappling a creature, the Shellborne can only use its claw to attack that creature, but its attacks automatically hit.
Wavebreaker Stance (Trait, Recharge 5-6)
- If the Shellborne takes damage from a melee attack, it can use its reaction to:
- Lock itself into place, gaining advantage on Strength checks and saving throws for 1 minute.
- Become immune to forced movement, including being pushed, pulled, or knocked prone.
Multiattack (3 Attacks Per Turn)
The Shellborne makes three melee attacks, choosing from Trident Strike, Claw Crush, or Shell Slam.
-
Trident Strike (Melee Weapon Attack, Reach, Piercing)
- Attack Bonus: +10 to hit, reach 10 ft., one target.
- Damage: 21 (3d8+6) piercing.
- Effect: On a critical hit, the target suffers bleeding wounds, taking 1d8 damage per round until healed.
-
Claw Crush (Melee Weapon Attack, Reach, Grapple)
- Attack Bonus: +9 to hit, reach 5 ft., one target.
- Damage: 24 (4d6+6) bludgeoning.
- Effect: If the target is already grappled, they take an additional 2d6 crushing damage.
-
Shell Slam (Melee Weapon Attack, Area Knockback)
- Attack Bonus: +9 to hit, reach 5 ft., all creatures in range.
- Damage: 18 (3d6+6) bludgeoning.
- Effect: Affected creatures must make a DC 16 Strength saving throw or be knocked back 10 feet.
So what do you thhink? Are you ready to have these warriors pollute the waters of your world, a la Pirates of Dark Water style? Yes I took inspiration from that great TV show from back in the day.
Thanks for reading. Until Next Time, Stay Nerdy!!
No Comments