Black Dragon
The Black Dragon is a boss appearing in Chrono Cross. It often causes darkness among your party, so BlackOuts and Panaceas are recommended. Repeated use of White Elements often results in the dragon casting AntiWhite. Fargo is capable of stealing the rare Black Plate armor from the Dragon, which absorbs all Black Elements cast against the wearer. Defeating the Dragon gives you the summon GrimReaper and the Black Relic, one of the six Dragon Relics needed to enter the Dead Sea.
It is also possible to obtain the Black Relic without fighting the Black Dragon at all. If you approach it in Another World's Marbule, you'll find it sleeping. Go up to it and press X and you'll simply obtain the Black Relic. To fight him, you must first wake him up by cleansing Home World Marbule as part of a lengthy sequence involving the Magical Dreamers