Malice

is a poisonous substance unleashed by Calamity Ganon in.

Characteristics
Malice can be found in several locations throughout Hyrule. It looks like a purple and black sludge that covers walls and floors. Malice can damage Link upon contact. Some pools of Malice have a Glowing Eyeball which, when destroyed, cause a large chunk of it to dissipate. Inside the Divine Beasts and Hyrule Castle, Malice may also have a mouth that is able to release Cursed Bokoblins, Moblins, and Lizalfos. These enemies will continue to spawn and attack Link until its corresponding Glowing Eyeball is destroyed, should there be one.

At the top of Mount Lanayru, Link can find Naydra covered in Malice. In order to free the dragon, he must destroy all the Glowing Eyeballs around its body with Arrows. During the final battle with Dark Beast Ganon, the remaining Malice surrounds Ganon and converts him into his original form.