Silver Dragon's Boon wondrous, rare (requires attunement)

This amulet carved from a silver dragon’s scale is only given as a gift and sign of trust. By the coloration you could guess it is from a younger dragon.   

As an action you can touch the amulet and begin concentrating, as if concentrating on a spell, to create a cloud of fog around you. You create a 20-foot-radius sphere of fog centered on yourself. The sphere spreads around corners, and its area is heavily obscured. It lasts for the next hour, until your concentration ends, or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it. While within this fog you have immunity to cold damage and blindsight out to 60 feet.     Once used this feature can not be used again until your next short or long rest