Cnidaran

The Cnidaran are a graceful, enigmatic species of jellyfish-like folk who dwell in the deepest reaches of the Azure Ocean, far beneath the surface where sunlight fades into twilight. Fluid in movement and ethereal in appearance, they are beings of flowing form and bioluminescent brilliance—semi-translucent bodies trailing elegant tendrils of light, pulsating with every heartbeat of the deep. They move through the water as if gliding on the currents of dreams, and many surface-dwellers speak of their encounters with awe and reverence, mistaking them for sea spirits or illusions.

A Cnidaran’s form is ever-shifting, with a central core resembling a humanoid torso encased in a dome-like bell that extends outward into undulating ribbons and stinging tendrils. Their colors range from ghostly blues and silvers to vibrant pinks and purples, and their glow serves both as communication and defense, pulsing in rhythmic patterns akin to language or emotion. Their tendrils can extend or retract at will, used for swimming, sensing magic, or in rare cases, defending themselves with jolts of venomous energy.

Cnidaran society is deeply communal and psychic, structured around what they call the Echo Current—a shared telepathic resonance that links them across vast distances. Through this current, they exchange memories, songs, and visions, creating a collective cultural memory that transcends individual lives. A young Cnidaran receives centuries of knowledge upon joining the current, while the wisdom of elders is never lost, simply flowing from one generation to the next.

Their cities are light-veiled sanctuaries carved into the walls of abyssal trenches and volcanic vents, illuminated by bio-crystals and grown coral shaped by ancient geomancy. Architecture pulses with gentle glow rather than rigid form, shaped by water and thought more than tools. Their spiritual traditions focus on symbiosis with the ocean, honoring the ancient leviathans, currents, and sentient reefs that guide their lives. Many Cnidaran see themselves as guardians of forgotten depths, keeping watch over ancient ruins, sleeping titans, and submerged planar rifts.

Cnidaran are natural sorcerers and mystics, often attuned to magic born of tides, time, and memory. Their spellcasting is fluid, reactive, and often tinged with illusions, divinations, or enchantments. Some practice a unique form of arcane artistry called Luministry, crafting glowing sigils in water that persist for days, telling stories or marking boundaries only other deep-sea dwellers can interpret.

Though rarely seen on land, a few Cnidaran have taken to exploring the surface world, drawn by curiosity, prophecy, or tides of destiny. These travelers typically wear enchanted hydrosuits or carry amulets of brinebound coral to retain moisture and communicate in air. They are often sought as oracles of the deep, dreamweavers, or tide-keepers, their presence seen as a good omen—or an ominous one, depending on the current they bring.

To encounter a Cnidaran is to glimpse a being shaped by pressure, patience, and poetry, a drifting soul who hears the ocean’s songs and responds in glimmers of light and ancient remembrance.

Geographic Distribution

HGtMH1

Cnidaran

HUMANOID

Cnidaran Traits

Size: Medium (5-7ft)

Speed: 30 feet, and you have a swimming speed equal to your walking speed.

As a Cnidaran, you have these special traits.

Amphibious

You can breathe air and water.

Species Option

When a polyp produces a medusozoa, it can birth one of two morphs: a nematocyst or a shimmerskin. The former is adapted for confrontation, combat, and conflict; and carries with it an innately toxic weapon. The latter relies on diplomacy, subterfuge, and enchantment to charm antagonists and avoid conflict. Together, these two morphs are capable of pursuing two very different strategies in interspecies interactions. Choose one of these options.

Nematocyst

Nematocyst

You have a long, barbed appendage, a natural weapon which you can use to attack with. You can use Dexterity instead of Strength for the attack rolls of your Unarmed Strikes. When you deal damage with an Unarmed Strike, you can deal piercing damage equal to 1d4 + your Strength or Dexterity modifier (your choice), instead of the bludgeoning damage normal for an unarmed strike.

Neurotoxin

As a bonus action, you can secrete a toxin and apply it to one weapon or piece of ammunition, which lasts for 1 hour. The first time you hit a creature with this weapon or ammunition, the creature must succeed on a Constitution saving throw (DC equals 8 + your Constitution modifier + your proficiency bonus) or be paralysed until the start of its next turn. Success or failure, the toxin then disappears from the item. Alternatively, you can use a bonus action to inject the toxin when you hit a creature with your nematocyst. You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Toxic Adaptation

You have advantage on saving throws against being poisoned, and you have resistance to poison damage.

Shimmerskin

Shimmerskin

As a bonus action, you can cause your skin to shimmer in a pleasing array of colours for 10 minutes. For the duration, you have advantage on all Charisma checks. Once you use this trait, you can’t do so again until you finish a long rest.

Hypnotic Phosphorescence

You know the minor illusion cantrip. Starting at 3rd level, you can cast the charm person spell once with this trait, and you regain the ability to do so when you finish a long rest. Starting at 5th level, you can cast the suggestion spell once with this trait, and you regain the ability to do so when you finish a long rest. You can also cast these spells using any spell slots you have of the appropriate level.

Charisma is your spellcasting ability for these spells. When you cast them with this trait, they don’t require material or somatic components.