Bestiarium is a series of illustrations about mythology from around the world.

Rokurokubi is a type of Japanese yōkai, typically described as female. Possess the ability to stretch their necks out to grotesque lengths.
Nekomata are a kind of cat yōkai. They are domestic cats that have grown old and transformed.

-"This Rokurokubi adopts old cats that have been abandoned by his owners in fear of the nekomata transformation"