Hollows

Hollows
Hollows are former Pluses (deceased Human souls) that lose their hearts to despair or remain in the real world for too long.

Development
Any spirit that is not guided to the Soul Society by a Shinigami via Konsō may eventually turn into a Hollow for various reasons.

They are corrupt spirits with supernatural powers that devour the souls of both living and deceased Humans. Hollows settle in Hueco Mundo, but can cross over to the Human World and Soul Society. The majority of ghosts peacefully move on to the Soul Society after their deaths. However, some stay in the living world to fulfill certain goals, such as pursuing after a loved one, protecting a particular location, or pursuing a grudge from beyond the grave. Hollows in rare cases have alternate diets that consists of cannibalism. They devour their own kind for extreme power enhancements and progress through evolution.

Appearance
All Hollows wear masks, which are formed from the hearts that they had lost as Humans. This mask protects the naked instinct that is left in a being after the loss of its heart, and to obscure the original identity of the Hollow. The masks of different Hollows can differ greatly in shape and form, but are always white and skull-like. The mask can be shattered, temporarily allowing the Hollow to regain its original identity, but it will regenerate after a short period once the Hollow takes over again. Hollows have widely varying physical characteristics, few of them rarely appear the same.

Hollows can range in appearance from furry (like mammals) through lizard-like to outright demonic. Hollows also vary in size, though it tends to be fairly consistent amongst the various classifications of Menos. In Hueco Mundo, some Hollows are no larger than common pets. Most common Hollows are about twice the size of an adult Human, though it can vary to a degree. It is revealed that the reason Hollows gain their unique appearance and individual powers. When a Hollow's heart is carved out by the hole in their chests, the lost heart becomes its mask, and changes its outward appearance to what it looks like as a Hollow. The powers a Hollow wields are also manifestations of its heart.