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AC 13 (natural armor)

HP 45 (6d10 + 12; bloodied 22)

Speed 10 ft., swim 40 ft.

Proficiency +2; Maneuver DC 14

Senses darkvision 60 ft., passive Perception 11

Languages Abyssal, Aquan, Giant, Primordial

Amphibious. The merrow can breathe air and water.


Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage, and the target is grappled (escape DC 14). Until this grapple ends, the merrow can’t attack a different creature with its claws.

Harpoon. Melee or Ranged Weapon Attack: +6 to hit, reach 10 ft. or range 20/60 ft., one target. Hit: 11 (2d6 + 4) piercing damage. The target makes a DC 14 Strength saving throw . On a failure, the merrow pulls the target up to 20 feet toward the merrow.


Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) piercing damage, or 9 (2d4 + 4) piercing damage if the target is grappled .


The merrow grabs creatures in its claws and then bites them. If an enemy is up to 20 feet away, it uses its harpoon and pulls the enemy into its reach. It uses its claws for opportunity attacks so that it can grapple fleeing creatures.


Gimra, Grayblood, Moroch, Sharktooth

Legends and Lore

With a History or Nature check, characters can learn the following:

DC 10 Merrows resemble merfolk, but they are much larger and eat the flesh of both aquatic and land-based humanoids.

DC 15 Merrows snatch prey with harpoons, then tear them to pieces with their claws and shark-like teeth. They seem unusually interested in land-dwellers and may interrogate them before dispatching them.

DC 20 Though they once ruled a mighty undersea empire, merrows now serve creatures such as aboleths , krakens , and sea hags .


Once the gifted servants of ancient demigods, merrows are former merfolk made monstrous by the destructive essence of their primeval patrons. 

Cults of the Kraken. According to legend, merrows were once a stately and handsome people that ruled over merfolk and other undersea cultures. Their empire was magnificent, if sometimes cruel. For reasons not fully understood, their power suddenly crumbled, and they retreated to deep waters as they metamorphosed into fanged monsters with a hunger for the flesh of their former subjects. Merfolk inherited the coral castles once home to their merrow monarchs.

Some sages believe that the merrow empire was founded upon a bargain made with the krakens , and that the empire’s eventual downfall came when the merrow were unwilling to pay the price for their power. Others question the truth of this legend. Did the merrow’s strange transformation even occur, or were ancient merfolk always ruled by flesh-eating monsters? 

Gifts for the Deep. Many merrows worship krakens and act as their agents. These cultists prowl the sea, hunting for treasures and knowledge to offer their masters. They value land-dwelling prisoners, asking them strange and seemingly meaningless questions. They may even give treasure or guidance to those who provide them with the answers they seek.


1 In its lair, feasting on victims

2 Carrying a giant drill which can be used to sink ships

3 Reeling in a harpooned dolphin or giant sea horse

4 Patrolling; attacks on sight


Sharks fighting over a corpse

2 A dead merfolk or sailor tied to a kelp rope

3 Shoals riddled with underwater caves

4 Terrified merfolk


Merrow inhabit drowned caves and dark ocean floors.

CR 0–2 merrow

Treasure 60 gp, 150 sp, elemental gem (water)

CR 3–4 2 merrow ; merrow with giant octopus or hunter shark ; merrow mage

Treasure coral bracelet (125 gp), shark tooth and lapis lazuli necklace (125 gp), potion of healing , potion of water breathing , javelin of lightning

CR 5–10 merrow mage with sea hag ; merrow mage with 1 to 3 merrows ; merrow mage with giant lanternfish (see lamia)

Treasure 600 gp, 1,500 sp, gold compass (125 gp), sealed map case containing nautical charts and a spell scroll of gust of wind , 2 feather tokens (anchor)

Monster Type Description

Monstrosities are magical beings usually native to the Material Plane. Some monstrosities combine the features of beasts and humanoids, like centaurs . Others have bizarre or unnatural appearances, like many-tentacled ropers . Monstrosities could only arise in a world suffused with magic.