You create a 50-foot-radius ground fog that only rises about 2 feet (knee-high on a Medium-size humanoid), centered on a point within range. The fog swirls mysteriously, so an invisible creature moving through the fog does not create enough of a stir to reveal its presence more readily than normal. The ground fog spreads around corners, and heavily obscures the ground beneath, as well as anything it covers, such as a Tiny creature, a prone human, or a hidden pit. It offers total cover to gaseous creatures, such as a spellcaster or vampire using gaseous form. It lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.