In the forgotten depths of the Thurian Seas, before the cataclysm that shattered the continents, there existed a beast that haunted the dreams of men and stirred the waters of dread.
Born in the shadow of prehistory, this ancient cryptid thrived in the abyssal reaches of the world’s oceans. A remnant of the primal epochs when monstrous life forms ruled both land and sea.
The leviathan, immense in size and deadly in purpose, was no mere curiosity of the natural world, but a predator of unparalleled ferocity.
Though its gargantuan bulk might suggest sluggishness, it was in truth a creature of startling speed. Its movements belying its enormity with pincers that could split the hull of a ship as a man might shatter a clay pot.
The Leviathan was armored in spikes as sharp and unyielding as the edges of a barbarian’s blade. It would sweep the water with these massive claws, rending and impaling prey. Those unfortunate enough to be skewered by its claws often met a grim fate. Dragged into the depths to be drowned or crushed by the creature’s unstoppable velocity.
What it could not devour outright, it inhaled into its grotesque crab-like maw. A sight that froze the blood of even the most hardened sailors.
The Leviathan was no silent stalker. Its attacks were the harbinger of destruction. Ships that sailed too close to its domain were torn asunder and entire fleets vanished beneath the waves.
Legends of the beast spread across the Thurian kingdoms, its shadow cast over the lore of countless seafaring peoples.
Some claimed it was a guardian of the deep, while others believed it was a relic of the gods’ wrath, a punishment left over from the Elder times.
Though it is said that this monstrous predator inspired the tales of the Leviathan in later scriptures, by the time the Hyborian age dawned, it was long gone, its kind likely extinguished in the fiery upheaval of the Thurian cataclysm.
Its colossal remains, if they existed, were swallowed by the shifting seas or buried beneath the earth’s crust.
Yet its memory lived on in the whispered fears of sailors and the myths of elder races. A shadow from a time when man was but prey to the great horrors of the world.
-Tales Of Dread Leviathan-
BEWARE! The Wrath of Poseidon!
-Leviathan Profile-
Lesser Atlantean Leviathan
Gargantuan Monstrosity (Unaligned)
Challenge: 17 (18,000 XP)
Proficiency Bonus: +6
Armor Class 21 (natural armor)
Hit Points 310 (23d12 + 138)
Speed 0 ft., swim 90 ft.
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 28 (+9) | 11 (+0) | 22 (+6) | 2 (–4) | 14 (+2) | 6 (–2) |
Saving Throws Con +12, Wis +8
Skills Perception +8
Damage Resistances cold; bludgeoning, piercing, and slashing from nonmagical weapons
Damage Immunities lightning
Condition Immunities charmed, frightened, paralyzed
Senses blindsight 120 ft., passive Perception 18
Languages —
Amphibious Pressure Sense. Can detect vibrations in water within 500 ft.
Traits
Atlantean Shellplate. The Leviathan’s chitinous plating renders it immune to pressure, corrosion, and most environmental effects of the deep ocean. Mundane weapons cannot penetrate its armor unless they are enchanted or made from relic Atlantean alloys.
Echo Roar (Recharge 5–6). The Leviathan emits a low-frequency burst through the water. Creatures within 120 feet must succeed on a DC 18 Constitution saving throw or be deafened and stunned until the end of their next turn. Non-magical structures of stone or weaker take 3d10 thunder damage.
Swallow Whole. When the Leviathan hits a Medium or smaller target with its Bite, it may attempt to swallow them. A swallowed creature is blinded, restrained, and takes 6d10 acid damage at the start of each of the Leviathan’s turns. If the Leviathan takes 50 or more damage in a single turn from inside, it must succeed on a DC 20 Constitution saving throw or regurgitate all swallowed creatures.
Actions
Multiattack. The Leviathan makes two attacks: one with its Pincer Slam and one with its Bite.
Pincer Slam. Melee Weapon Attack: +15 to hit, reach 15 ft., one target.
Hit: 31 (4d10 + 9) slashing damage. If the target is Large or smaller, it must succeed on a DC 20 Strength saving throw or be hurled 30 feet and knocked prone.
Bite. Melee Weapon Attack: +15 to hit, reach 10 ft., one target.
Hit: 45 (6d12 + 6) piercing damage. If the target is Medium or smaller, the Leviathan may attempt to Swallow Whole as a bonus action.
Thrash Burst (Recharge 6). The Leviathan spirals violently, creating a vortex. Creatures within 30 feet must succeed on a DC 18 Dexterity saving throw or take 8d10 force damage and be pulled 15 feet closer.
Legendary Actions
The Leviathan may take 3 legendary actions, one at a time, at the end of another creature’s turn.
- Detect. The Leviathan makes a Wisdom (Perception) check.
- Tail Sweep. Creatures within 15 feet must succeed on a DC 18 Dexterity saving throw or take 2d10 bludgeoning damage and fall prone.
- Crush Depth (Costs 2). The Leviathan dives with massive force. Swimming creatures within 40 feet must make a DC 17 Strength saving throw or be dragged 20 feet deeper and take 4d6 bludgeoning damage.
☠ Optional Add-On: Maw Parasite
Huge Aberration (Symbiotic), Chaotic Evil
The Lesser Leviathan’s already terrifying jaws may host a Maw Parasite, a squid-like abomination that lives within the beast’s gullet, replacing its tongue with a living horror.
When present, replace Bite with:
Maw Lash.
Melee Weapon Attack: +14 to hit, reach 40 ft., one target.
Hit: 24 (4d6 + 9) slashing damage + 9 (2d8) necrotic. Target must succeed on a DC 18 Strength saving throw or be pulled 20 feet toward the Leviathan’s mouth.
If the target ends up adjacent to the Leviathan’s head, the parasite may use Gore Maw as a bonus action.
Gore Maw (Recharge 5–6).
The parasite reveals its true triple-beaked face and attempts to latch onto a target adjacent to the Leviathan’s mouth. The target must make a DC 19 Dexterity saving throw or become latched.
- While latched, the target is restrained and takes 21 (6d6) necrotic damage per turn. They cannot breathe or speak.
- The latch remains until the Leviathan or parasite dies, or the victim escapes with a successful DC 20 Strength check.
Additional Traits
Independent Reflex. The Maw Parasite can act even if the Leviathan is incapacitated. It may make one Maw Lash as a reaction once per round if a creature attacks within 10 feet of the head.
Fleeing Horror. If the Leviathan dies, the parasite attempts to detach and swim away (swim speed 50 ft.), potentially becoming a future threat.
Open Source Usage in the Atlantean Cycle
The Atlantean Cycle is committed to fostering a collaborative and evolving mythos through open-source worldbuilding principles. While retaining a cohesive vision, we encourage adaptation, expansion, and reinterpretation within the following framework.