The Plane of Hades
The layers of the plane Hades are called the Three Glooms - places without joy, hope, or passion. A gray land with all ashen sky, the plane of Hades is the destination of many souls that are unclaimed by the solars of the other planes or the Demon Princes of the Abyss. These souls become larvae and spend eternity in this place that lacks a sun, a moon, stars, or seasons. Leaching away color and emotion, this gloom is more than most visitors can stand.
A larva is a miserable fiend that retains the facial features of its previous form but has the body of a fat worm. A larva has only a few faint memories of its previous life. The plane of Hades is crawling with larvae. Night hags, liches, and rakshasas harvest them for use in vile rituals. Other fiends like to feed on them as well.