Black Fog is the most basic of Ing forms encountered in Metroid Prime 2: Echoes. This untouchable gaseous entity is the only form that Pure Ing can take when entering Light Aether, otherwise they cannot survive in the light dimension's environment. The Ing fog can only last so long without a host and will attempt to possess the nearest life-form or mechanoid as soon as it enters the light realm. Samus Aran had witnessed the Black Fog on multiple occasions during her adventure on Aether, but was completely incapable of affecting it with any of her weapons.