Water Form. The undine can enter a hostile creature's space and stop there. It can move through a space as narrow as 1 inch wide without squeezing.
Freeze. If the undine takes cold damage, it partially freezes; its speed is reduced by 20 feet until the end of its next turn.
Aquatic Spirit. The undine can breathe water and walk on it.
Innate Spellcasting. The undine's innate spellcasting ability is Charisma (spell save DC 15, +5 to hit with spell attacks). The undine can cast the following spells:
At will: druidcraft, shape water, cure wounds, purify water, water breathing (1 other creature)
1/day: charm person
Multiattack. The undine makes two slam attacks.
Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 3 (1d6) bludgeoning damage.
Description
Undines are water elemental creatures that inhabit peaceful magical forest pools and waterfalls. Undines are exclusively female, and appear as beautiful human women with a blue translucent body composed entirely of water. Like Dryads, undines seek to "marry" a human man, drawn by the energy of his soul, and to create offspring. Undines will often kidnap unsuspecting men wandering alone in the woods, and keep him imprisoned under the water in their lair, granting him water breathing. If a man is unfaithful to the undine or tries to escape, she will drown him. The offspring of an undine and a human will be a Water Genasi.
An undine's body is entirely liquid, although parts of it can become more solid and jelly-like at will. Undines will always flee from combat if possible, and hide under the surface of water. Undines are mostly calm and lethargic in nature, only getting upset if a rival tries to steal their husband. Like Dryads, undines are created as a result of powerful natural magic granting sentience and form to beautiful landscapes with water. If you listen carefully, an undine's beautiful singing can sometimes be heard over the sound of moving water.