Here There Be Monsters
Azan-gund, The Night Caller
Transparent iron whistle in the shape of a curled up dragon
Azan-gund is made of the rare material “nephclium”, a transparent iron occasionally found in the underdark. The Duergar pretty much have the market cornered on this material.
Once per week the Night Caller may be used to raise a standard Zombie (p.288 Bestiary) which serves the bearer of the whistle faithfully until it is destroyed. For the whistle to function it must be blown over a buried corpse and it must be dark.
The whistle detects as evil.
The history of the object is unknown. It was found in the Sunless Citadel, a fortress which seems to have been built by some ancient dragon cult. It has been forged into the shape of a dragon curled up like a snail.