Malice is an enemy substance and obstacle in Breath of the Wild. It is a black and purple substance found throughout the four dungeons of the Divine Beast, Hyrule Castle, and various assorted locations across Hyrule. Touching the substance will unavoidably damage Link. Small eyeballs can also appear with the corruption; particularly within the dungeons. Destroying the eyeballs will remove the immediately surrounding Malice. These eyeballs can be destroyed by using melee weapons, arrows, or remote bombs. However, the eyes can only be killed when they are open. These eyes cannot be added to the Hyrule Compendium.
Cursed heads of Stalkoblins, Stalizalfos and Stalmoblins can appear from areas of Malice that have maws in them, which have a total of 30 health each, and unlike the eyeballs, these monsters can be added to the Hyrule Compendium, and will repeatedly respawn until the particular section of Malice is destroyed by attacking the eyeball.
However, this can only be achieved where available. Places across Hyrule which are blighted with pools of Malice will be found (like the Coliseum Ruins), but it may well be irremovable.
The flat black fringes of Malice pools can be stepped on without damage, but touching the solid mass will incur in damage.
A Malice eyeball and its maw spewing Cursed Moblins