Black Bokoblins are enemies in Breath of the Wild.
Hyrule Compendium Entry
Black Bokoblins are a stronger variant of Blue Bokoblins. They are much more resilient and are armed with stronger weapons than their common counterparts, including Dragonbone Boko Clubs and Dragonbone Boko Bats. Black Bokoblins may be found in monster camps and occasionally on roads where they may attack passing travelers. Black Bokoblins may also sometimes be found going on hunts while riding Horses.
Black Bokoblins share an attack pattern with other Bokoblin counterparts. On the ground, Black Bokoblins mainly attack by swinging and slamming their held weapons. In the event that their weapon is lost or stolen, they will search for any other available weapons nearby and use them instead. In some monster camps, Black Bokoblins may also be found standing on top watch towers, where they may alert other monsters to Link's presence by blowing a horn. These Bokoblins may also be equipped with Bows that they use to snipe intruders with Arrows.
Black Bokoblin riding a Horse
Link fighting Blue and Black Bokoblins in the Great Plateau in Master Mode