Shimmergloom is a shadow dragon that appears in the novel Streams of Silver, which is the second book in The Icewind Dale Trilogy, written by the American author R. A. Salvatore.
This trilogy features the adventures of Drizzt Do’Urden and his group of friends, who are collectively known as the Companions of the Hall.
In Streams of Silver, Shimmergloom is under the control of the duergar and serves as the main antagonist in the the story, where he resides in the depths of Mithral Hall, the ancestral home of Bruenor Battlehammer, who is one of Drizzt’s closest companions.