Merrow

Merrow haunted coastal waters, preying on fisherfolk, merfolk, and any other edible creature that crosses their path. These savage monsters snatched and devoured unwary prey, hauling drowned corpses back to their underwater grottoes to feed. They were created when a group of merfolk were pulled into the Abyss by the Demogorgon and warped over generations into hulking, evil monstrosities.

Merrow

 * Senses: Darkvision.
 * Languages: Abyssal and Aquan.
 * Amphibious:  The merrow can breathe air and water.
 * Attacks:
 * Multiattack: The merrow can make two attack, one with it claw and one with its bite.
 * Claw: The merrow can make a claw attack.
 * Bite: The merrow can make a bite attack.
 * Trident: The merrow can attack with its trident and can pull a creature 20 feet toward itself.

Merrow Shallow Priest

 * Senses: Darkvision.
 * Languages: Abyssal and Aquan.
 * Amphibious:  The merrow can breathe air and water.
 * Attacks:
 * Spellcasting: The Priest is a 6th level spellcaster (save DC 13) and can cast the following spells:
 * Call Lightning
 * Thunderwave

The Mighty Nein encountered merrows in their lair in the Labenda Swamp and defeated a handful of them.

The Mighty Nein defeated two merrow and a shallow priest near the wreckage of the Tide's Breath whilst exploring the Diver's Grave.