Rusalka

Withered Tresses. If a rusalka is kept out of water for 24 consecutive hours, its hair and body dry into desiccated swamp weeds and the creature is utterly destroyed.

Innate Spellcasting. the rusalka's innate casting ability is Charisma (spell save DC 15). She can innately cast the following spells, requiring no material components: at will: control water, suggestion, tongues, water walk (can be ended freely at will) 1/day: dominate person

Watery Camouflage. In dim light or darkness, a rusalka that's underwater is invisible.

Breathless Kiss. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: the target is grappled (escape DC 13) and the rusalka draws all the air from the target's lungs with a kiss. If the rusalka has movement remaining, she drags the grappled creature into deep water, where it begins suffocating.

Drowning Hair (1/Day). The rusalka's long hair tangles around a creature the rusalka has grappled. The creature takes 33 (6d10) necrotic damage, or half damage with a successful DC 15 Constitution saving throw. In addition, until it escapes the rusalka's grapple, it is restrained and has disadvantage on Strength checks to break free of the grapple.