From publisher blurb:
Baba Yaga, a hugely powerful mage with blazing mobility and powerful hand-to-hand abilities, is presented here as a CR 26 total party threat. The write up is complete with legendary and lair abilities, a character background and history, and some adventure hooks to help you fit her into your game.
Did we mention the hut with chicken legs?
The first in our series of Boss Stat books, Baba Yaga is a match for a high level party, and makes a great Big Bad for the later days of your campaign.