(Lam-a-run-TOZ) is a Desconocido known as "Claws of the Coast" patrolling and defending Leilon and ranges stretching north past Neverwinter and south past Baldur's Gate. She often took the form of a striking red-headed woman who captained the flagship of the Scaly Eye, a shipping fleet that battled pirates and other threats for over a century.
Decades ago, she and her present crew retired from the ship-based patrolling. The Swords of Leilon built a structure honoring her on a small island off their coast - carving a triumphant form of her into the cliffs and assisting her in dedicating a magical shrine within to the dragon god Bahamut (the platinum dragon), which the dragon can use to commune with the deity. Members of the Scaly Eye still live within the Bronze Shrine, to assist in the island's upkeep, which has also been the destination of pilgrimages.
https://forgottenrealms.fandom.com/wiki/Lhammaruntosz
In recent decades, Lhammaruntosz had retreated inside the lair, becoming reclusive. She would leave on rare occasions to hunt for food, returning as soon as possible, and the usual range of her patrols offered opportunity to pirates and other threats (such as the Cult of the Dragon) in her absence.
In 1492 DR, Our Party discovered this was due to the presence of a demon in the lair disguised as sea-mold and barnacles on one of the windows. This almost unknown type of demon (called an "alkilith") had driven the dragon mad. The demon was driven away - and Lhammaruntosz regained her mind after a few days of recovery.
Soon after she disappeared - last seen repelling a Desconocido summoned by Fheralai Stormsworn to help steal the Death Knight Dreadnought from Ularan Mortus.