Black Knight is the third chest keeper in the Death Volcano.
Black Knight is one of few bosses who is armored and is mysterious as much as Red Knight.
After defeating the boss, player receives a 
Blue Chest as a reward. Black Knight may be defeated only once per timeline.
Achievements
After defeating the Black Knight for the first time, player receives an achievement "Clear Area XVI" which multiplies non-tap monsters' DPS by 1.02.