The Cursed Queen is a legendary boss creature, spawned by drinking the Potion of Trials. She must be defeated in order to acquire the Treasure Hunter's Scimitar, the weapon around which the quest In Search Of A Scimitar revolves.
Spawning her requires it to be night, and for the player to have acquired the Potion of Trials, available by talking to any Sea Scholar once the player has progressed far enough into In Search Of A Scimitar. Upon drinking the potion, the message 'The Cursed Queen is near...' will appear and a few seconds will pass before the player loses 30 health points and the Cursed Queen appears. Drinking the potion while the players has less than 30 health points will kill them.
She does not drop any loot other than the Treasure Hunter's Scimitar, making her useless other than to finish the quest, or farm Gold Coins by selling the scimitar.
The Cursed Queen's attacks poison the player. The poison is much stronger in comparison to the Spider Queen's, and her attacks deal a fair amount more damage.