Buy me a coffeeDinosaur, Elasmosaurus, the Serpent of the Sunken Silence
“From the depths of the ancient sea rises the serpentine-necked terror — the Elasmosaurus, a 50-foot nightmare with jaws that strike like a lightning-fast guillotine!”
The Elasmosaurus is a titanic marine reptile with a sleek, torpedo-shaped body and a ridiculously elongated neck stretching nearly half its total length. Its skin glistens slate-blue to kelp green, patterned with mottled striations that aid in camouflage. The narrow, crocodilian skull houses rows of backward-curving, needle-like teeth, perfectly designed to trap slippery prey. Its four paddle-like flippers churn the water in eerie silence, and its eyes, positioned high on the skull, give it a menacing, all-seeing gaze beneath the waves.
Behaviour
Elasmosaurus is a solitary ambush predator, relying on stealth and deception rather than speed or brute force. It moves gracefully, often drifting motionless beneath the surface for hours before striking with a sudden, whip-fast motion of its neck. Though not inherently aggressive toward humanoids, it is territorial and easily provoked, particularly during mating seasons or when guarding feeding grounds.
Habitat
Found in vast inland seas, deep coastal trenches, and lost primordial lakes, Elasmosaurus prefers waters where visibility is low and prey is plentiful. Ancient mariner tales speak of dead ships in calm bays, where no storm or beast was ever seen — only long, winding drag marks across the decks.
Modus Operandi
Elasmosaurus hunts with a deceptive grace, using its long neck to probe into schools of fish, underwater caves, or even shipwrecks. It often lurks beneath drifting debris or floating carcasses, mimicking harmless driftwood until prey approaches. When it strikes, its neck snaps forward with shocking speed, impaling and seizing creatures up to Medium size before dragging them down into the depths. If wounded, it will thrash violently and dive deep, circling back to stalk its attacker with chilling patience.
Motivation
Elasmosaurus acts purely on ancient instinct, driven by hunger, territory, and reproduction. However, some ancient seers and druids claim certain individuals have been awakened by deep-sea magic, tasked with guarding forgotten ruins or cursed relics on the ocean floor. In such cases, its behavior becomes eerily tactical, suggesting a primal intelligence awakened from the abyss.
Elasmosaurus, 5e
Elasmosaurus 3.5
Elasmosaurus
Huge Beast (Aquatic), Unaligned
- Armor Class 17 (natural armor)
- Hit Points 168 (16d12 + 64)
- Speed 10 ft., swim 60 ft.
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 22 (+6) | 14 (+2) | 18 (+4) | 2 (−4) | 12 (+1) | 5 (−3) |
- Saving Throws STR +10, CON +7
- Skills Perception +5, Stealth +5 (in water)
- Damage Resistances Cold; Bludgeoning from nonmagical attacks
- Senses darkvision 60 ft., passive Perception 15
- Languages —
- Challenge 10 (5,900 XP) — Proficiency Bonus +4
- Environment aquatic (seas, lakes, flooded ruins)
Amphibious Predator.
Elasmosaurus can breathe both air and water.
Lurker of the Deep.
While underwater and motionless, the Elasmosaurus has advantage on Dexterity (Stealth) checks to hide and can remain still for hours, appearing as driftwood or wreckage.
Flexible Neck.
Elasmosaurus can make melee attacks against creatures within 30 feet of its body due to its long neck. It cannot make opportunity attacks outside a 10-foot radius.
Actions
Multiattack.
The Elasmosaurus makes two attacks: one with Bite and one with Fin Slam, or two Constricting Neck attacks.
Bite. Melee Weapon Attack: +10 to hit, reach 30 ft., one target.
Hit: 24 (4d8 + 6) piercing damage. If the target is Medium or smaller, it must succeed on a DC 16 Strength saving throw or be grappled (escape DC 16) and restrained.
Fin Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one creature.
Hit: 17 (2d10 + 6) bludgeoning damage. If the target is Medium or smaller, it must succeed on a DC 16 Strength saving throw or be pushed 10 feet away and knocked prone.
Constricting Neck. Melee Weapon Attack: +10 to hit, reach 20 ft., one target.
Hit: 16 (2d10 + 6) bludgeoning damage. The target is pulled 15 feet closer. If this causes the target to collide with a solid surface or another creature, it takes an additional 1d6 bludgeoning damage per 5 feet dragged.
Swallow Prey (Recharge 5–6).
The Elasmosaurus makes a bite attack against a grappled, Medium or smaller creature. On a hit, the creature is swallowed.
- While swallowed, the creature is blinded and restrained, has total cover, and takes 21 (6d6) acid damage at the start of each of the Elasmosaurus’s turns.
- If the Elasmosaurus takes 30 or more damage on a single turn from a swallowed creature, it must succeed on a DC 18 Constitution saving throw or regurgitate the creature, which falls prone in a space within 10 feet.
Legendary Actions
The Elasmosaurus can take 2 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature’s turn. It regains spent legendary actions at the start of its turn.
Detect.
The Elasmosaurus makes a Wisdom (Perception) check.
Neck Flick.
The Elasmosaurus makes a Constricting Neck attack.
Depth Plunge (Costs 2 Actions).
The Elasmosaurus dashes and dives, creating a 10-foot-radius vortex. All creatures in that area must succeed on a DC 16 Strength saving throw or be dragged 15 feet underwater and knocked prone (if capable of standing).
Elasmosaurus
Has a thick, ovoid body with fins instead of legs and a long, snaky tail and neck. Though it resides primarily in the water, an elasmosaurus only breathes air. An elasmosaurus has a total length of some 30 feet, including a tail half as long as its entire body, and weighs about 5,000 pounds. Observers who see only its head or tail might easily mistake it for a massive snake.
Source(s) 3.5E Monster Manual I, 3E Monster Manual I, Forgotten Realms (MC3), 1E Monster Manual 1, Monstrous Manual
| Elasmosaurus | |
| Huge animal | |
| Hit Dice | 10d8+66 (111 hp) |
| Initiative | +2 |
| Speed | 20 ft. (4 squares), Swim 50 ft. |
| Armor Class | 13 (-2 size, +2 Dexterity, +3 natural), touch 10, flat-footed 11 |
| Base Attack/Grapple | +7/+23 |
| Attack | Bite +13 melee (2d8+12) |
| Full Attack | Bite +13 melee (2d8+12) |
| Space/Reach | 15 ft./10 ft. |
| Special Attacks | – |
| Special Qualities | Low-Light Vision, Scent |
| Saves | Fort +15, Ref +9, Will +4 |
| Abilities | Strength 26, Dexterity 14, Constitution 22, Intelligence 2, Wisdom 13, Charisma 9 |
| Skills | Hide -4*, Listen +4, Spot +9, Swim +16 |
| Feats | Dodge, Great Fortitude, Toughness (2) |
| Environment | Warm aquatic |
| Organization | Solitary, pair, or herd (5-8) |
| Challenge Rating | 7 |
| Treasure | None |
| Alignment | Always neutral |
| Advancement | 11-20 HD (Huge); 21-30 HD (Gargantuan) |
| Level Adjustment | – |
Combat
An elasmosaurus is aggressive and attacks anything it notices. The creature is strong, fast, and highly maneuverable, able to turn quickly and lunge at prey. When hunting, it travels with its head out of the water, snapping down quickly to seize prey.
Skills *An elasmosaurus has a +8 racial bonus on Hide checks in water.