Haha, tricked you. Laughing idiotically, the Yochrofl changes its shape and takes the form of a deformed female Drow, something resembling a limping giant spider or its original form.

Magic resistance. The Yochrofl has advantage against magic spells and effects.

Spider Climb. The Yochrofl can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Innate Spellcasting. The Yochrofl's spellcasting ability is Charisma (spell save DC 14). It can innately cast the following spells, requiring no material components:

At will: detect thoughts, web

1/day each: dominate person

Web Walker. The Yochrofl ignores movement restrictions caused by webbing.

Armed attack. The Yochrofl rips off one of her own limbs, suffering 1d6 points of permanent damage. She then uses the extremity to hit a creature with a double attack (two blows).
Melee Weapon Attack: +6 to hit, reach 5ft / 1,50m, one target. Hit: 5 (1d6 + 2) bludgeoning damage + 21 (6d6) poison damage.

You take my breath away. As an action, the Yochrofl can decide to turn into a misty form or retake her original form. If she drops to 0 HP in her misty form, she reappears in her true form. In the misty form, the Yochrofl is unable to speak. However, she can move up to 30ft / 9m, can hover, pass through any area that is not airtight and enter a creature's space as well as its lungs (without using up another action).
Whenever a creature begins its turn in a space occupied by the Yochrofl, it must succeed on a DC14 Constitution saving throw or be poisoned until the start of the its next turn. A creature that is poisoned this way cannot take any actions, reactions or bonus actions and cannot move.
If a creature stays in a space that is occupied by a Yochrofl for more than 1+ its Constitution modifier minutes, it drops to 0 HP and needs to roll death saving throws.