Cleon
Legend
Okay, let's try expanding that a bit and seeing were it gets us. I borrowed a bit of the Xorn's Earth Glide SA to replace the previous meld into stone and phase door ability, since I feel that may be a better match.
Wall Bound (Su): A tomb warden is part of an enchanted stone wall. The wall must be at least 5 feet thick and voluminous enough to contain all the tomb wardens that are part of it (i.e. a wall with 4 wardens must occupy at least 4 5-foot squares). Some walls are far larger than the wardens bound to them, giving these golems space to maneuver.
A tomb warden can take the form of a shallow carving on the surface of its wall. In its relief carving form, the golem can see and hear out of the stone surface that it is melded with. The golem can also take on a three dimensional form and move through the stone of its wall as easily as a fish swims through water. This burrowing leaves behind no tunnel or hole, nor does it create any ripple or other signs of its presence. Tomb wardens may never leave the wall they are part of. It may lean out of its wall to attack intruders, but must keep at least half its body within the wall. Any carvings or paintings on the wall will shift and alter to accommodate the movement of the tomb warden. The tomb warden can switch between its 2D and 3D forms as a free action.
