Flying Dutchman

The Flying Dutchman is a Hardmode mini-boss that spawns during the Pirate Invasion event. It has four cannons that fire cannonballs towards the nearest player, and it will occasionally spawn standard Pirate Invasion enemies. The Flying Dutchman does not disappear after the Pirate Invasion is over (though it will explode if it has not been engaged before the invasion ends), and defeating the Flying Dutchman will not end the invasion. The Flying Dutchman can only be defeated by destroying all four cannons. Several Flying Dutchmen can appear during a single Pirate Invasion, or none at all. They only appear when the event progress has passed 50%, and where there is at least 40×40 tiles space.

Tips

 * Any weapons that can hit multiple targets at once are good for taking out the cannons.
 * Due to the way it moves and the way the cannonballs fire, it is very easy to find positions where it cannot hit the player, yet they can hit it.
 * Weapons that can be used in these situations include any kind of summoning weapon, the Daedalus Stormbow, the Meteor Staff, and the Flying Knife.
 * Due to the fact that they stop upon hitting a wall, and continuously spawn pirates, the Flying Dutchmen can be stopped above a half block deep pit of lava (or other trap) and used to farm the various items pertaining to the Pirate Invasion.
 * Farming Lucky Coin/Discount Card/Coin Ring is most efficient from Flying Dutchman, rather than from common pirates. After getting event progress to 50%, the player can ensure 10 Flying Dutchmen per event by getting high enough above ground (using a small platform or flying mount), but not too high, so that spawned enemies will be in the "Active Rectangle" and will despawn after 12.5 seconds, and then spawn again. Eventually, a Flying Dutchman will spawn (usually it takes a short time). After killing it, the process is repeated until the event ends. Parrots could reach the player this way too, but they can be killed safely, since they do not count towards event progress.
 * A Minecart with a sufficiently long track is useful for dodging the Flying Dutchman's attacks. It can be attacked with ranged or magic weapons from the Minecart.

Trivia

 * The Flying Dutchman is one of the only enemies in the game to have a special death animation: When it dies, the sail rips to shreds and gently floats down. The other enemies are the Moon Lord and the Celestial Pillars, which makes the Flying Dutchman the only non-Lunar Event enemy to have a special death animation.
 * The real-life  is a legendary ghost ship that can never make port and is doomed to sail the oceans forever, a myth that is likely to have originated in the 17th century. In ocean lore, the sight of this phantom ship is a portent of doom.
 * There is a rare chance to see The Flying Dutchman flying throughout the background during the day, even in Pre-Hardmode.

History
Hollandais volant 荷兰飞盗船