Nezumi Kun

Little is known about the origins of Nezumi Kun, even the scholars of the Blue library could only guess at the occult rituals and black magic used to create this “Son of Nezumi”. The savage Yokai appears more wild and feral than its “father”, striking from nowhere, only a rank stench left to mark its passage before it scuttles away into the darkness. Waiting and lurking in the shadows waiting for instruction from a faceless unseen evil.

Trivia
Nezumi-kun translates to "rat boy"