Tomb Swarm

Instead of setting up a Tomb Swarm on the battlefield, you can place them to one side and say that they are set up beneath the ground. In any of your movement phases, you can set the unit up on the battlefield more than 9" from any enemy models. This is the unit’s move for that movement phase. The unit can burrow back underground in any of your future movement phases. If it does, remove the unit from the battlefield – it can return in a later turn as described above.

If a Tomb Swarm burrows back underground as described above, it is joined by more of its scuttling brethren who had remained hidden. You may restore D3 slain models to the unit.