Nereid

Nereids are a race of water-dwelling fey, distantly related to dryads and similar to sirines. Like dryads, they are powerful spellcasters, combining an innate ability for Charm Person spells with an arsenal of combat spells.
==In Baldur's Gate==
A single nereid, Shoal, appears at the Shipwreck's Coast, though she counts as a monster, rather than a humanoid.
==In Siege of Dragonspear==
Another nereid can be encountered during the events of Baldur's Gate: Siege of Dragonspear as part of the quest Strunk's Elementals in the Underground River.