FusionDex.org

Onbat hides itself within stone walls waiting to ambush prey, tracking them via the slight reverberations in the rocks from every footstep. Once close enough, it hurls its stone body at its target headfirst to knock them out.

While living in pitch-black caverns, their eyes gradually grew shut and deprived them of vision. There is a magnet in its brain that prevents an Onbat from losing direction while tunneling.