Ice Walk. The Yuki Onna can move through non-magical ice and snow as though it were difficult terrain.

Deathless Nature. The Yuki Onna does not need to eat, breathe or sleep.

Mimicry. The Yuki Onna can mimic animal sounds and humanoid voices. A creature that hears the sounds can tell they are imitations with a successful DC 16 Wisdom (Insight) check.

At will: dancing lights, minor illusion, vicious mockery, ray of frost

Innate Spellcasting. The Yuki Onna is an 11th-level spellcaster. Her spellcasting ability is Charisma (spell save DC 16, 1d20+8 to hit with spell attacks). The Yuki Onna knows the following spells.

1st level (4 slots): charm person, ice knife

2nd level (3 slots): alter self, suggestion

3rd level (3 slots): dispel magic, glyph of warding, slow

4th level (3 slots): phantasmal killer, polymorph, ice storm

5th level (2 slots): dominate person, seeming, cone of cold

6th level (1 slot): Otto’s irresistible dance

Frosted Touch Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) cold damage.

Illusory Appearance. The Yuki Onna covers herself and anything she is wearing or carrying with a magical illusion that makes her look like another creature of her general size and humanoid shape. The illusion ends if the Yuki Onna takes a bonus action to end it or if she is defeated.

The changes made by this effect fail to hold up to physical inspection. For example, the Yuki Onna could appear to be regular person, but someone touching her would feel her hard frozen skin. Otherwise, a creature must take an action to visually inspect the illusion and succeed on a DC 20 Intelligence (Investigation) check to discern that the Yuki Onna is disguised.

Invisible Passage. The Yuki Onna magically turns invisible until she attacks or casts a spell, or until her concentration ends (as if concentrating on a spell). While invisible, she leaves no physical evidence of her passage, so she can be tracked only by magic. Any equipment she wears or carries is invisible with her.