Invisible Stalker

Basic Information:
An invisible stalker is an air elemental that has been summoned from its native plane and transformed by powerful magic. Its sole purpose is to hunt down creatures and retrieve objects for its summoner. When it is defeated or the magic that binds it expires, an invisible stalker vanishes in a gust of wind. As their name implies, stalkers are invisible and their true form is largely unknown. They can only be perceived as a shimmering mass of air on the Material, Astral and Ethereal planes, similar to the refraction that's caused by hot air passing in front of cold. Invisible stalkers are known to deeply resent any task given to them, but are relentless in pursuing its completion. If the stated task takes the stalker a week or more to complete, it will gradually pervert the stated intent of their assignment and look for loopholes. Because of this, commands need to be carefully worded. Some hold a deep distrust or outright hatred of humanoids, due to suffering at the hands of ones who summones them or having been killed by humanoids.

Encountered in:
Chapter 17: Dragon Barrow

(Click on the chapter for more information or to listen to the chapter)