Mothron

Mothron is a powerful flying Enemy that spawns during the Solar Eclipse event and passes through Blocks. It can only spawn after Plantera /  all three Mechanical Bosses have been defeated. Mothron attacks by lunging at the player. Occasionally it lands on blocks to lay several Mothron Eggs that will spawn Baby Mothrons if they are not destroyed in time, much like Lepus.

Tips

 * The basic steps:
 * Prepare an open, flat arena.
 * Equip a good set of wings, and either Hallowed armor with Helmet (which gives a ranged bonus and ranged critical strike chance), Chlorophyte armor with Helmet (which gives a ranged bonus, and each crystal leaf projectile will deal 100 damage), or Shroomite armor. Turtle armor and Beetle armor offer more defense, but they're better suited for melee, and offer no ranged bonuses.
 * Gelatinous Pillion can also be useful as an alternative to wings as the diagonal speed of the mount exceeds Mothron's speed when flying down vertically or flying up vertically.
 * Ranged and Magic weapons are ideal. The Piranha Gun's projectile damages any enemy it comes in contact with while still latched to the target (can be defeated in 20-25 seconds in normal mode, 40-45 seconds in Expert mode). Also good choices are the Megashark, the Unholy Trident (except for its high mana cost) and the Crystal Serpent due to its splash projectiles. Any Broken Hero Sword made weapon (True Night's Edge, True Excalibur and Terra Blade) or Yoyo is recommended for melee players.
 * Ranged damage boosting accessories (for melee users, melee boosting accessories).
 * The player can run from Mothron while throwing Light Discs or Magic Daggers at it.
 * If the player is lucky enough to have one from a previous Solar Eclipse or from the current one, the Death Sickle is very effective against Mothron, constantly hitting it and keeping it at bay for a precious few seconds.
 * Mothron is most vulnerable when it is laying its eggs.
 * The best thing to do is to kill the eggs before they hatch, as the Baby Mothrons can be very annoying to kill. It is also useless to farm them, as they drop no loot.
 * Another strategy is jumping down a Hellavator and shooting up, however the effectiveness of this can vary greatly class-to-class and strategy-to-strategy.

Trivia

 * Mothron is a reference to Mothra from the Mothra 1961 movie. The subtle change in its name follows the trend of Terraria enemies' and bosses' names ending with the suffix -ron, such as Skeletron, Duke Fishron, and Pigron.
 * If the Eclipse finishes, or all players die, Mothron floats up to the sky and despawns, similar to the Martian Saucer and Pumpkin/Frost Moon Event Bosses. In addition, it becomes invincible after the end of the Eclipse.
 * Like the Ice Golem, Sand Elemental and Dreadnautilus, Mothron is not considered a mini boss or a boss even though it has stats comparable to one. This is because it drops a banner, not a trophy.
 * Techically, Baby Mothron should be in their larval state at birth.
 * Mothron acts similarly to Lepus from the Old Mobile Version and 3DS Version, in the sense that it lays eggs that spawn weaker versions of itself.
 * According to Grox, the reason for Mothron dropping the broken hero sword is because Mothron ate it.