Baba Yaga was a legendary witch of Russian folklore that lived inside a chicken leg house, and counted dead men's fingers.

To ensure that Rasputin's spirit would always be safe, Baba Yaga placed half of it within the roots of Yggdrasil, the world tree.

When Baba Yaga was counting the fingers of the dead in a cemetery, she attempted to use a skull (that once belonged to a former-devotee named Katayev) to lead her to the Sabbath.

Baba Yaga's diminished power causes her to disappear from the world and reside in a pocket dimension created in the image of her Russia as it appeared long ago.

During the events of Wake the Devil, after having her servant Koku present an iron maiden to Rasputin in his failed attempt to ensure Ilsa Haupstein's survival in the coming apocalypse, Baba Yaga observed Hellboy being cast into the darkness by Hecate alongside Dagda and Edward Grey.

Though Rasputin declined her offer, Baba Yaga collected what remained of his soul after he was dispatched by Hecate in the aftermath of the Conqueror Worm.

In the events of Darkness Calls, after refusing to be their queen after Hecate was disposed of, Baba Yaga asks the witches to give her Hellboy so she can exact her revenge within her world.

Drained of almost all her power as Koschei is defeated, Baba Yaga attempted to use Rasputin's soul before a fearful Koku snatched the acorn that contained the evil monk away from her and cast it through the roots of the World Tree into Hell.

In a last ditch effort, Baba Yaga ordered Koschei to throw his dagger into Hellboy's back as he ascended to the exit of her world.

Before the loss of her eye and depowering, she was often seen in the graves of the dead, counting the fingers of the corpses before sucking in their souls and breathing them into empty skulls to create ghostly lanterns.

These lanterns are shown to hang from the branches of the world tree and completely fill the interior of her chicken legged house.

Several other deities and Russian folklore figures exist in the faux Russia with her, but she is shown to be extremely oppressive to them and will kill any who oppose her.

It is explained that Hellboy had previously shot out Baba Yaga's right eye many years earlier when he stopped her after she had attempted to resurrect the ghost of Joseph Stalin.