This sling stone is carved to look like a fluffy cloud. Typically, 1d4 + 1 fog stones are found together. When you fire the stone from a sling, it transforms into a miniature cloud as it flies through the air, and it creates a 20-foot-radius sphere of fog centered on the target or point of impact. The sphere spreads around corners, and its area is heavily obscured. It lasts for 10 minutes or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.