Silver Boss Bokoblin
"The mightiest of all Boss Bokoblins. It's a wonder that they're related at all to the lowly, garden-variety Bokoblin. The evil power of the Demon King dwells in their bodies and horns, enabling formidable attacks. And watch out for the elite minions that hang around them too."
Silver Boss Bokoblins are larger enemies that appear in Tears of the Kingdom.
Tears of the Kingdom
These large overworld enemies usually serve as mini-bosses that surround a Bokoblin Camp. They have significantly more power and health than their smaller Silver Bokoblin counterparts. When defeated, they will drop Boss Bokoblin Fangs, Boss Bokoblin Guts, and a Silver Boss Bokoblin Horn.
In spite of its huge shape and naming, it does not count as a boss in-game.