Large humanoid (karkinoi), chaotic evil

Armor Class 15 (natural armor)
Hit Points 153 (18d10+54)
Speed 30 ft., swim 40 ft.

22 (+6) 10 (+0) 16 (+3) 6 (–2) 10 (+0) 7 (–2)

Saving Throws Con +6, Str +9
Skills Athletics +9, Perception +6
Senses darkvision 60 ft., passive Perception 16
Languages Aquan
Challenge 6 (2,300 XP)

Special Traits

  • Constrict. A karkinoi can only have two creatures grappled at once. If a creature is grappled by the karkinoi at the beginning of its turn, it takes 22 (4d6+6) bludgeoning damage.
  • Sideways Scuttle. Whenever the karkinoi takes the Dash action, it can move twice its normal movement speed.
  • Water Dependency. A karkinoi can only breathe underwater but can hold its breath out of water for 3 hours.


  • Multiattack. The karkinoi makes two claw attacks.
  • Claw. Melee Weapon Attack: +6 to hit, 10 ft. reach, one target. Hit: 19 (3d8 + 6) bludgeoning damage. Instead of dealing damage, the karkinoi can grapple the target (escape DC 15).


Monstrous hunters and bullies of the ocean depths, karkinoi are hulking crab-like humanoid brutes that live only to destroy creatures that dare cross their path and then feed on the corpses of the vanquished. While karkinoi can walk on land, they do not enjoy long periods away from the sea, as they dry out, crack, and eventually suffocate. Karkinoi stand over 9 feet tall and weigh over 800 pounds.

Brutal. Though not mindless, they have no inclination to build civilizations or even settlements, living in roving gangs or nomadic tribes. The tools they use in their more humanoid appendages are always scavenged, usually from victims, and are discarded when broken or of no more immediate use.

Pursuits such as crafting, learning, and diplomacy are a waste to them; they see these as the activities of food-creatures not strong enough to see the world as it is—a stage for domination, feeding, and spawning. Even when these brutes band together, it is usually to spawn or to face sources of food that are too strong for only one or two karkinoi alone.

Shore Raiders. Large hordes of karkinoi come together to hunt inhabitants of coastal settlements. Striking at night, they do as much damage as possible before dragging their meals into the sea.

They make such attacks night after night until the settlement is destroyed or the resistance becomes too fierce, at which point the horde disbands and each karkinoi makes its own way in the sea.

Coastal raids are part of the karkinoi breeding cycle. The corpses that they drag off into the ocean are tethered to masses of eggs and serve as food for karkinoi spawn. The spawn develop a taste for land-meat and crave it, ensuring the next generation of hungry raiders.

Section 15: Copyright Notice

Sea Monsters (5E) © 2021, Legendary Games; Authors Michael Ritter, Michael “solomani” Mifsud, Robert J. Grady, Mark Hart, Jeff Ibach, Alex Riggs, Scott D. Young, Jeff Lee, Matt Kimmel, and Jason Nelson.

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