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Megafauna, Archelon, “Ancient Guardian of the Primordial Sea”

“Lurking beneath the waves, Archelon glides silently through ancient seas—an armored leviathan with jaws strong enough to crush bone and flippers that can outswim death itself.”

Megafauna, Archelon
Archelon ischyros – giant sea turtle from Campanian of Pierre Shale in South Dakota
Dmitry Bogdanov – dmitrchel@mail.ru

Archelon is a massive marine reptile with a leathery, ridged shell stretching over 13 feet long and paddle-like flippers extending even wider. Its hooked beak resembles a snapping turtle’s, capable of cracking crustacean shells or shearing through soft-bodied prey. Its eyes are dark, steady, and unblinking, betraying an intelligence born of instinct and deep time.

Behavior:
Solitary and slow-moving, Archelon is a passive creature unless provoked. It drifts through prehistoric oceans or lost-world lagoons like a living reef. When threatened, it uses surprising agility in water, retreating to the depths or battering foes with its powerful flippers and crushing beak. On rare occasions, a nesting Archelon may become aggressively territorial, especially during egg-laying seasons.

Habitat:
Archelon inhabits warm, shallow inland seas, prehistoric coastlines, or sunken hollow-earth grottoes. It prefers calm waters rich with jellyfish, mollusks, and drifting invertebrates. Ancient druidic circles or sea-aligned factions may consider it a sacred beast or protector of submerged temples.

Modus Operandi:
Archelon patrols the ocean floor, using its sense of vibration to detect movement. Though slow on land and incapable of true terrestrial travel, it may haul itself ashore to nest on remote islands. In combat, it turns sideways to present its massive shell and uses its flippers to displace water violently, creating wakes or even knocking small boats off course.

Motivation:
Driven purely by instinct, Archelon seeks food, calm territory, and nesting grounds. However, some ancient specimens are bound by magical currents or druidic pacts to serve as eternal guardians of relics, shipwrecks, or natural wonders beneath the sea.

An ancient relative of the smaller leatherback sea turtle, the archelon has an exceedingly powerful bite, and doesn’t hesitate to use it to deter aquatic nuisances.

Like other sea turtles, female archelons come ashore to lay and bury their eggs in sandy beaches, preferably facing deep water and without coral reefs. Once done, they return to the sea, leaving their eggs defenseless.

These creatures are often used by coastal tribes as guardians and escorts from island to island. Aquatic creatures, particularly locathah, often use them as beasts of burden, but their relatively slow swim speed makes them poor mounts.

  • Archelon 5e
  • Archelon Pathfinder

Archelon

Large Beast, Unaligned

Challenge: 3 (700 XP)  Proficiency Bonus: +2

Armor Class 15 (natural armor)

Hit Points 85 (10d10 + 30)

Speed 10 ft., swim 40 ft.

STRDEXCONINTWISCHA
18 (+4)8 (–1)16 (+3)2 (–4)14 (+2)5 (–3)

Saving Throws

Con +5, Wis +4

Skills

Perception +4, Stealth +2 (in water)

Damage Resistances

Bludgeoning, Piercing (nonmagical)

Senses

Darkvision 60 ft., Passive Perception 14

Traits

Leathery Shell.

While Archelon withdraws into its shell (see Withdraw), it gains resistance to all damage except force and psychic.

Amphibious.

Archelon can hold its breath for up to 1 hour.

Ocean Camouflage.

While underwater and motionless, Archelon has advantage on Dexterity (Stealth) checks.

Actions

Multiattack.

Archelon makes two attacks: one with its Beak and one with its Flipper Slam.

Beak.

Melee Weapon Attack: +6 to hit, reach 10 ft., one target.
Hit: 15 (2d10 + 4) slashing damage. If the target is wearing medium or heavy armor, it must succeed on DC 13 Strength saving throw or be grappled (escape DC 13).

Flipper Slam.

Melee Weapon Attack: +6 to hit, reach 10 ft., one target.
Hit: 13 (2d8 + 4) bludgeoning damage. The target must succeed on DC 13 Constitution saving throw or be stunned until the end of its next turn.

Withdraw (Recharge 5–6).

Archelon withdraws into its shell until the start of its next turn. During this time:

  • AC increases by 4 (to 19).
  • Gains advantage on Constitution saving throws.
  • Speed is 0 and cannot take reactions.

Reactions

Deflecting Shell.

When hit by a ranged attack underwater, Archelon can add +2 to AC against that attack.

Tactics

  • Usually avoids combat but defends territory or nests fiercely.
  • Uses Withdraw to soak damage when pressured.
  • Employs Flipper Slam to stun and Beak to grapple armored foes.

The shell of this immense sea turtle easily spans 12 feet in length. Its narrow head ends in a hooked beak.

Archelon CR 5

XP 1,600
N Huge animal
Init +5; Senses low-light vision, scent; Perception +10

DEFENSE

AC 19, touch 9, flat-footed 18 (+10 armor, +1 Dex, -2 size)
hp 59 (7d8+28)
Fort +9, Ref +6, Will +5

OFFENSE

Speed 15 ft., swim 50 ft.
Melee bite +10 (2d8+9)
Space 15 ft.; Reach 10 ft.
Special Attacks capsize (DC 25)

STATISTICS

Str 22, Dex 13, Con 19, Int 2, Wis 12, Cha 6
Base Atk +5; CMB +13; CMD 24 (28 vs. trip)
Feats Improved Initiative, Iron Will, Lunge, Weapon Focus (bite)
Skills Perception +10, Swim +18
SQ hold breath

ECOLOGY

Environment warm or temperate water or coastlines
Organization solitary or bale (2-6)
Treasure none

Section 15: Copyright Notice Pathfinder Roleplaying Game Bestiary 3, © 2011, Paizo Publishing, LLC; Authors Jesse Benner, Jason Bulmahn, Adam Daigle, James Jacobs, Michael Kenway, Rob McCreary, Patrick Renie, Chris Sims, F. Wesley Schneider, James L. Sutter, and Russ Taylor, based on material by Jonathan Tweet, Monte Cook, and Skip Williams.

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