Baba Lysaga

Everything in the swamp around Berez is afraid of her. The Vistani say she turns adventurers into goats, feeds the goats to her ravens, and plucks the ravens' feathers to make her scarecrows. She lives in a hut carried by a walking tree and calls herself the keeper of this land.

The party robbed her of a glowing jade gem, and none of their spells touched her. She let them go, after walking across the water to whisper to Cassius that she'd find him. She came for the gem as a swarm of bats, and fell to her knees when Strahd walked out of the trees. She called him her master and her son. He called her mother, and sent her home.