Eater of Worlds

"A horrible chill goes down your spine..." "Screams echo around you..."

The Eater of Worlds is a giant Corruption-themed worm boss (resembling a Devourer, but much larger) with eyes on every segment of its body. It is summoned using the Worm Food from within The Corruption, or by destroying 3 Shadow Orbs.

The Eater of Worlds is not a single target, but a string of 50 body segments with individual life counters. When any inner segment is destroyed, it splits into multiple smaller worms, each with their own head and tail. Each section of the Worm must be killed in order to defeat the entire boss.

Fighting the Eater of Worlds is the only way to obtain Shadow Scales, which are required to craft the Nightmare Pickaxe, The Breaker, and Shadow Armor. Defeating the Eater of Worlds also produces usable quantities of Demonite Ore. Individual segments drop some of these when killed, with a larger bonus drop upon defeating the entire entity.

If your world generated Crimson instead of Corruption, this boss will be replaced by the Brain of Cthulhu. The Eater of Worlds is immune to the Poisoned, On Fire!, and Cursed Inferno debuffs.

Tips

 * Farming the Eater of Worlds is one of the most effective ways of making money prior to Hardmode. Mid-game armor and weapons will make the fight easy, and selling its drops will yield 9 to 11 each time, on average.
 * Weapons that pierce for multiple hits are effective, due to the Eater's large size (eg. Flails, Spears, Grenades, Spiky Balls, Molotov Cocktails, Vilethorn). The Harpoon is also effective, and is best used when being charged by its head.
 * The individual worms have a tendency to retreat into the ground when their heads are destroyed.
 * During Hardmode, it is an effective means of farming Soul of Night. One Soul of Night can be dropped per segment, the percentage being the same as with other mobs.
 * During Hardmode, the Eater can be summoned to heal yourself when your health is low, even while fighting other bosses: Your equipment at this stage will kill segments quickly, and each segment drops more than enough hearts to not only offset their negligible damage, but also heal your character significantly, if not fully.
 * Perhaps the easiest way to take care of the Eater of Worlds is using the Meteor Armor with the Space Gun. The Space Gun has high damage for this point in the game, and it pierces through enemies. Coupling this with the Meteor Armor's set bonus of the Space Gun using 0 Mana, you can easily pierce and kill multiple segments at once.
 * If you are lucky enough to obtain a Water Bolt from the dungeon's upper section without having to fight Skeletron, it makes the boss battle trivial thanks to its piercing ability.

History
Dévoreur de Mondes Eater of Worlds Пожиратель миров