Sussurus

A sussurus, also known as a susurrus, a headless droning ape, or a singing ape, was a creature with an undead-pacifying dronesong.

Description
Sussuri appeared as headless quadrupedal figures of vaguely humanoid, almost apelike shape. They had an exoskeleton filled with small gaps that drew in sustaining air, which created the creature's signature dronesong.

Some sages considered sussuri to be a form of plantlife, distantly related to the shambling mound. These accounts described the creatures as being made up of rotting bamboo. Others said that sussuri appeared to be covered in shards of glass, which encircled the holes that riddled their bodies.

Ecology
Those sussuri that roamed in more tropical climes were commonly in competition with shambling mounds over territory and prey.

Some sussuri acted as servants or companions to djinn.