A yōma born from beneath the earth. It has a large body and can deal massive damage. If you shatter the orb that protrudes from its outer crust, you will see the woman the monster has absorbed. Unfortunately, they are already fused with the monster and cannot be saved.
This Yōma is based of the False Wall yokai of Japanese mythology.
There is also a dark blue/gray variant with a pale-skinned girl embedded within the blue gems.