Quiver

The Quiver is a type of Adamant Arms and Artifice combat hollow. It's named after an obsolete collective noun for a group of cobras.

On first glance, you might not think this is a hollow at all. But once the low, wide three-legged firing brace starts to walk, you’d understand that these artillery machines are able to move and even leap with great force and speed, making them excellent at holding (or hammering) an unstable frontline.