For those who might be interested I came across news of a recently published novel by American writer Catherynne M. Valente entitled simply 'Deathless' . Seeing that title piqued my interest given discussions last night.
Like The Tiger's Wife it is set within modern times and yet draws on myth and folklore of the region coupled with modern history though in this case the Soviet Union.
Using my Goggle skills I found a blog that reviewed these books side-by-side.
"The Tiger’s Wife by Téa Obreht and Deathless by Catherynne M. Valente have more in common than their March release dates. Both feature tales of animal husbandry and a deathless man. Slavic folklore provides a common foundation for both books but one is written as a fable and the other as a fairy tale, a distinct difference."
I shall certainly be ordering a copy of 'Deathless' to discover more about this intriguing figure of folklore.