Writhing Fog

In-game description
"Writhing Fog This spell conjures a cloud of writhing fog that chills and hinders anyone within its area other than the caster. Creatures in the fog take 1d3 points of cold damage per round. In addition, there is a 20% chance that they must save vs. Death or be slowed for 1 round. Creatures immune to cold damage do not suffer any adverse effects from this spell."