Merrow

Merrow were undersea merfolk-like monsters from the Abyss who terrorized the waters. Demogorgon often sent his merrow to the Material Plane to bully life there.

Society
Merrow on the Material Plane lived in undersea caves. They filled their abodes with treasures and used the rotted corpses of dead creatures tied to kelp to mark their territory.

Combat
A merrow was often armed with a harpoon. It also fought with its sharp claws and its fanged bite.

History
Merrow were created when a tribe of merfolk found an idol to Demogorgon that drove them all insane. The king of this tribe demanded a blood sacrifice to the idol that opened a rift to the Abyss. The corrupted merfolk slowly transformed into the monsters now known as merrow over multiple generations there.

Appearances

 * Dead in Thay
 * The Rise of Tiamat
 * Princes of the Apocalypse