Black Hinox Horn
Black Hinox: 100% drop chance
Black Hinox Horn is a material found in Tears of the Kingdom.
Tears of the Kingdom
"A horn wrapped in dangerous debris. It's easy to work with and greatly increases the attack power of a weapon when attached. Cook it with a critter to make an elixir."
Black Hinox Horns can be obtained by defeating a Black Hinox, which can be found scattered in locations across Hyrule and the Depths. They have a fuse attack power of 27, and make blunt weapons when fused. Merchants and shops pay 60 rupees per Black Hinox Horn.
They can also be used in cooking elixirs, which increment Link's stats for a period of time. However, as they do not contribute anything special or unusual to the result - increasing the effect duration of an elixir by an average-level 40 seconds per horn - they are wasted by doing so, as monster parts from lesser and easier-to-defeat enemies, with a lower sale price, can be used instead.
Nine Black Hinox Horns are required as part of the cost of upgrading the Yiga Set to ★★★★ level, three each for the Yiga Mask, Yiga Armor and Yiga Tights. They are not used in any other armor upgrades, nor are they required for any quests.