Slug, Giant Sea

Surfacing from the depths emerges a colossal slug. Its swollen flesh is a hideous mottled greenish-gray and rows of undulating gills line its 30- foot long body. Probing with a large set of antennae it gnashes its great mouth exposing a gullet lined with rows and rows of serrated teeth.

Giant Sea Slug CR 12

XP 19,200
N Gargantuan vermin (aquatic)
Init +0 Senses darkvision 60 ft.; Perception +6


AC 19, touch 6, flat-footed 19 (+13 natural, -4 size)
hp 164 (15d8+90 plus 7)
Fort +15, Ref +5, Will +5
Immune vermin traits


Speed swim 50 ft.
Melee bite +19 (2d8+16 plus grab plus paralysis)
Space 20 ft.; Reach 15 ft.
Special Attacks capsize, paralysis (1d6 rounds, DC 23), swallow whole (2d8+16 bludgeoning damage plus 2d6 acid damage, AC 16, hp 25)


Str 32, Dex 10, Con 22, Int 1, Wis 11, Cha 1
Base Atk +11; CMB +26 (+30 grapple); CMD 36 (can’t be tripped)
Feats Cleave, Diehard, Endurance, Power Attack, Toughness, Weapon Focus (bite), Vital Strike, Weapon Focus (slam)
Skills Perception +6, Swim +31


Capsize (Ex)

A giant sea slug can attempt to capsize a boat or ship by ramming it as a charge attack and making a CMB check. The DC of this check is 25, or the result of the captain’s Profession (sailor) check, whichever is higher. For each size category the ship is larger than the sea slug’s size, the sea slug takes a cumulative -10 penalty on this CMB check.


Environment temperate aquatic
Organization solitary
Treasure none

Spending a large portion of its life crawling across the floors of lakes and seas, the giant sea slug is rarely encountered, save by accident or happenstance. Stories are told of these great monsters surfacing beneath ships, tipping them over, and then feasting on the survivors. There is little truth to these stories, as the giant sea slug prefers a diet of plants and aquatic sea life. Instead, giant sea slugs are docile creatures, dieting on aquatic plants such as kelp, seaweed, and coral. They are known to surface for air occasionally though they do not require air to breathe. Most of the stories that speak of these creatures attacking ships are the result of a giant sea slug surfacing for air beneath a ship that happened to be in the way.

A typical encounter with a giant sea slug occurs when the creature surfaces beneath a ship or boat and capsizes it. The giant sea slug isn’t really attacking, it’s just surfacing for air – and once again a ship or boat has gotten in its way. They may inadvertently swallow sailors or swimmers who are in the water when the giant sea slug opens its mouth. Non-aggressive, they rarely engage in combat, however if provoked, they attack opponents by biting with their sharp, jagged teeth.

Section 15: Copyright Notice

Giant Sea Slug from the Tome of Horrors Complete, Copyright 2011, Necromancer Games, Inc., published and distributed by Frog God Games; Author Scott Greene.

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