Martian Saucer

The Martian Saucer is a large flying Hardmode, post-Golem mini-boss that spawns in the Martian Madness event. The Martian Saucer moves through blocks. It has four turrets with independent health meters that must each be destroyed before damaging the saucer itself becomes possible. The turrets include two rocket launchers and two laser machine guns. In addition, the saucer itself fires a large beam ("death ray") that can only fire directly downward, and which cannot be destroyed independently. The player can damage the core only if all four turrets have been destroyed. If you have already defeated the pirate army already you could think of it as a harder version of the Flying Dutchman.

After all four turrets have been destroyed, the boss shoots a deathray that deals the second highest damage in the game, beating the Rune Wizard and only beaten by the Dungeon Guardian.

Behavior
The Martian Saucer has three attack phases it cycles through in order. It always moves a short distance between them. After the turrets and cannons are destroyed, the saucer stops and shakes for a moment as its core becomes exposed. The core may be damaged during and after the transformation. In this stage, the Saucer will fire only its death ray, always moving towards the player. The death ray deals massive damage, even to those with Solar Flare armor. It also fires yellow flames that linger on the ground for a while that deal damage if touched, like the Greek Fire projectiles from the Mourning Wood.
 * 1) The Saucer locks onto your current location and shoots a volley of lasers at that location. This attack does not follow you if you move around.
 * 2) The Saucer fires multiple small homing missiles from its cannons.
 * 3) The Saucer positions itself above the player before unleashing its "death ray," traveling in the direction you were in.

Tips

 * To dodge its first attack, hover above or below its lasers. To dodge its second attack, run away from the Saucer as it shoots so that most of the missiles hit the ground in front of the player. To avoid its third attack, as well as its final enraged stage, simply stand under blocks.
 * A very easy way to defeat the Saucer's second stage is to create either a ceiling or bunker thick enough to block the laser and use a weapon that can pierce through blocks or fires from the skies. For mages this involves a Meteor Staff, Blizzard Staff, Nimbus Rod or, should the player have obtained it already, the Lunar Flare. Rangers can make use of a Daedalus Stormbow and while Holy Arrows aren't necessary, the stars they produce can deal a significant amount of damage. Melee characters are able to use a Death Sickle, as it may be useful if there are blocks above you that are making a shield. Yoyos such as the The Eye of Cthulhu, the Possessed Hatchet, Flying Dragon or Solar Eruption; however due to their limited range, and so landing a hit on the Saucer can prove very challenging. Summoners with a Stardust Dragon or Stardust Cell can easily sit the fight out. A Frost Hydra or Stardust Guardian can also be placed on top of the ceiling for some extra damage. The homing projectiles from the Scourge of the Corruptor can also be used to easily defeat the saucer from cover.
 * It is easy to dodge the Saucer during its berserk stage by moving away from the Saucer wherever it is while flying. This means that the "death ray" can't catch up to the player and that the player won't touch the yellow flames it produces.
 * With a decent weapon and armor, such as Nebula Blaze with Nebula Armor, the Martians may be killed quick enough to prevent the spawning of the Martian Saucer.
 * If the player is encased in any type of structure that is big enough to negate any splash damage from the rockets, the fight will be completely effortless. With a 1x1 hole for a Yoyo to fit through, even a Wooden Yoyo will be able destroy the Martian Saucer. However, this will take a great deal of time.
 * Unlike most bosses, the Martian Saucer does not possess any attacks capable of penetrating blocks. This can be exploited by latching onto the boss with the Piranha Gun and quickly going inside a safe bunker with walls and ceilings four blocks thick. To quickly exit and enter the bunker, do not make a "door" using Active Stone Blocks and Pressure Plates, because sometimes after the Piranha Gun is latched onto the Saucer, small enemies will follow the player into the bunker and can't be killed while the player remains latched onto the Saucer. Instead, use Teleporters between the inside and the top of the bunker. The player will need to reattach the Piranha Gun when the boss enters its second stage, but for the most part, they can simply wait as the Piranha Gun continuously deals damage while the boss is unable to attack.
 * If the "Wet" buff from Cute Fishron is activated (or the player is below half health), the player can fly slightly faster than the Saucer.
 * In the second phase of the Martian Saucer's attack, a great combo for taking it out is the Megashark with Chlorophyte Bullets, along with some Wings. The player should fly as high as they can, then descend and move side to side, avoiding the deathray while also firing.
 * The Aerial Bane is extremely effective against the Martian Saucer, as it deals extra damage to flying enemies, and splits on contact, dealing extra damage to the parts below; additionally the explosion damages multiple parts.
 * A way to defeat this without being damaged is taking advantage of the spectre mask, since it releases lost souls when damaged, you can use it to destroy it. Use statues; the more you use, the more souls are fired. Just make sure your weapon goes through enemies, and stay under blocks. It will take a while but it totally works.

History
Soucoupe Martienne 火星飞碟