Clam, Giant

Clam, Giant

A large, brightly-colored shell shifts in the current. Seemingly split or divided down the middle, its interior is a dazzling golden brown.

Giant Clam

XP 50 ()

Unaligned Large

Initiative +0


AC 14 (natural armor)

hp: 22 (3d10 + 6)

Immunity: Psychic damage; fright, stun

Vulnerability: Fire damage


Speed: Swim 5 ft.

Melee Attack—Swallow: automatic hit (reach 5 ft.; one Medium or smaller creature). Hit: Target creature must make a successful DC 13 Dex saving throw or be grappled and restrained inside the clam’s shell (see Swallow, below).


Str 16 (+3), Dex 1 (–5), Con 15 (+2),

Int 1 (–5), Wis 10 (+0), Cha 9 (–1)

Languages: None

Skills: Stealth +2

Senses: Tremorsense 60 ft.


Camouflage: The rough shell of a Giant clam is draped with barnacles, anemones, and bits of coral, which help it to blend into its environment. A Giant clam has a +2 bonus on normal Stealth checks despite its low Dex score, and it gets tactical advantage on Dex (Stealth) checks to conceal itself before an encounter (since they have nothing but time, lying there on the sea bottom).

Swallow: A swallowed creature is blinded and restrained. It takes 1 acid damage automatically at the start of each of the Giant clam’s turns. Only one Medium or smaller creature can be inside the Giant clam at one time, and a Giant clam can swallow only one creature per 24 hours. A swallowed creature is unaffected by anything happening outside the Giant clam or by attacks from outside it. A swallowed creature can get out of the Giant clam by winning aStr contest against it— the swallowed character has tactical disadvantage in this contest—or by using 5 feet of movement after the Giant clam is dead.


Environment: Warm or temperate

Organization: Solitary or cluster (2–10)

Giant clams are generally found in coastal waters no deeper than 60 feet. Many species of Giant clams subsist strictly on a diet of sunlight, and as such are never found at depths where sunlight can’t reach. Such Giant clams typically live in shallow seas or attached to coral reefs near the surface.

Some species of Giant clams feed not only on sunlight but also on what they can filter from the water, usually small plants and animals, and sometimes the occasional swimmer. Giant clams simply wait until an unsuspecting target swims too close to the clam. When a creature at least one size smaller than the clam comes within reach, the clam sucks the prey into its interior and clamps its shell shut. It slowly digests its meal and expels any indigestible material (such as metal, stone, jewels, and coins) into the surrounding water. Air-breathers trapped by a Giant clam face the danger of drowning as well.

A Giant clam moves by pushing out a small “foot” and sliding itself along the sea bottom.