Meteor Head

Meteor Heads are flying enemies that spawn once you enter a Meteorite Biome. They usually spawn in packs of 3-5 and will override the spawning of other Enemies in the area, meaning that no other Enemies will spawn as long as there are Meteor Heads around. The only exception is the Ocean biome. The normal Ocean Enemies (Jellyfish, Sharks, etc.) will still spawn and the Meteor Heads will not.

Meteor Heads follow typical Flying AI, with the exception that they do not collide with solid blocks and can fly straight through them, making them a difficult enemy without a weapon that can also go through blocks like a Vilethorn.

Meteor Heads will stop spawning once there are only 49 / 22  or fewer blocks of the Meteorite left, which is usually about 10-20% of the total size of a normal Meteorite crash site. Because of this mechanic, a player can place 50 / 23 or more Meteorite wherever they like to spawn Meteor Heads in place of the normal spawns in an area.

Meteor Heads also have a very small chance of dropping some Meteorite, so it is partly possible to farm them for their drops, although after two or three landings players should be able to make everything they can out of it, and in the case of Meteor Shot, better replacements are obtainable later on.

Tips

 * Once a player obtains the Meteor Head Banner by killing 50 Meteor Heads, they can hang it within 50 tiles from where they are mining Meteorite. The banner grants players +50% / damage inflicted with all weapons and -25% /  damage taken from melee attacks against Meteor Heads.
 * One way of defeating Meteor Heads is to defend oneself by using a pickaxe. While mining, the player can hit the Meteor Heads as they're flying towards them, as long they're coming from one direction. Suggested items are a Cobalt Shield to negate knockback and an Obsidian Skull to prevent damage from the Meteorite itself. With the Tinkerer's Workshop, a player can combine the two into an Obsidian Shield, providing both benefits and using only one accessory slot. A Grappling Hook or Ivy Whip can be used in place of a Cobalt Shield to hold the player in place.
 * Another suggested method is based on the fact that Meteor Heads do not respawn instantly. With a high tier weapon a player should be able to kill all of them rather quickly, provided they have grouped up, giving the player some time to act without their interference.
 * High-tier weapons like the Dark Lance, Night's Edge or greater (found in Pre-Hardmode) are capable of destroying Meteor Heads in a single blow. A convenient way to get rid of them easily early on is the Vilethorn, as it can both shoot through walls and kill the Heads in one hit. As it drops from Shadow Orbs, it is very probable that players will have one before going to mine meteorite.
 * Any type of Spear can be used to kill Meteor Heads through walls and have a distance between them.
 * Muskets are also a very effective weapon to fight Meteor Heads, as the high damage of the musket is quite effective against the relatively low health of Meteor Heads.
 * After Hardmode, getting a full set of Turtle armor grants a player the ability to kill Heads without much hassle, as they deal more damage than they have health, effectively killing themselves with the armor's thorns effect. Although not as useful in a Hardmode world, this ability can be used to AFK farm Meteorite on a non-Hardmode world.
 * In multiplayer, one player can mine while the other player attacks the Meteor Heads with a high knockback weapon such as Boomerangs or high tier pre-Hardmode weapons such as Night's Edge.
 * A minion or Crimson Rod is usually able to kill all attacking Meteor Heads while the player mines.

History
流星头 Meteorenkopf Tête de météore 운석 머리 Meteor Head Meteor Head Осколок метеора