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Sea Serpent

Gargantuan monstrosity (titan), chaotic evil

Armor Class 19 (natural armor)
Hit Points 296 (16d20 + 128)
Speed 0 ft., swim 50 ft.

28 (+9) 21 (+5) 26 (+8) 12 (+1) 17 (+3) 5 (-3)

Skills Perception +8
Damage Immunities bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunities charmed, frightened, prone
Senses darkvision 120 ft., passive Perception 18
Challenge 15 (13,000 XP)


  • Siege Monster. The sea serpent does double damage to objects and structures.
  • Water Breathing. The sea serpent can breathe only underwater.


  • Multiattack. The sea serpent makes one bite attack and one constrict attack.
  • Bite. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 42 (6d10 + 9) piercing damage.
  • Constrict. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 20 (2d10 + 9) bludgeoning damage, and the target is grappled (escape DC 18). Until this grapple ends, the creature is restrained. The sea serpent can grapple up to three Large or smaller creatures.
  • Stench Breath (Recharge 5-6). The sea serpent exhales a foul, poisonous gas in a 120-foot cone. Each creature in that area must succeed on a DC 18 Constitution saving throw or take 55 (10d10) poison damage and be poisoned until the start of its next turn. On a successful saving throw, the creature is immune to the sea serpent’s breath for 24 hours.


One of the largest monsters in the sea is the legendary sea serpent. It makes any journey across the ocean a perilous voyage.

Powerful Swimmers. Sea serpents are strong swimmers and are surprisingly agile in the water. They seem to be more active in wild, intense storms. Their superior swimming ability lets them easily navigate these wild waves.

Ocean Hazard. Those adventurers brave enough to travel across wide stretches of ocean might have to face this nightmare. Some maps mark the locations where a sea serpent has been sighted.

Salty Mouth. A sea serpent’s breath is so awful it will harm any nearby creatures. The odor is rumored to smell like a salty dead whale.

Section 15: Copyright Notice

Monsters of the Wilderness: A Collection of Monsters for 5th Edition Copyright 2022 Cawood Publishing Author Andrew Cawood

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