The Queen Black Dragon is one of the best monsters to kill for money. There is not much variation in the value of her drops, especially compared to bosses whose average profit per kill is largely due to the price of a handful of rare drops. The QBD is fought in four phases, each progressively more difficult than the last. After depleting her health in each of the four phases and activating the four dragonkin artefacts, the QBD will return to her slumber and you will be able to descend from the platform and claim your reward from the dragonkin coffer.