The Purple Cavalry Hat is a very unique hat. It can only be obtained during the Raven's Cove Story Quest (available at Notoriety level 30) by earning the bonus quest playing Undead Poker for the friendly Clubheart ghosts. Once you sell this hard-earned hat, there is no chance of you being able to get it back. It requires a very hard task, winning 5000 Gold in Undead Poker in a single sitting (not getting up) - for some it can be extremely challenging.
Game Tip: You can get a friend to heal you while playing Undead Poker so you don't die (make sure you do it before sitting down or they may not be able to attune you).
Bonus Quest: Win 5000 gold in Undead Poker in a single sitting.
Game Note: This is for female pirates only. The Magenta Ostrich Hat is the bonus quest item for males.