Eater of Worlds

The Eater of Worlds is one of thirteen boss enemies. It is a giant Corruption-themed worm (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.

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, Vilethorn). The Harpoon is also effective, and is best used when being charged by its head.
 * During Hardmode, it is an effective means of farming Soul of Night. Every segment killed will give you 4-5 Souls.
 * 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 more than enough hearts to not only offset their negligible damage, but also heal your character significantly, if not fully.

History
Dévoreur de Mondes Eater of Worlds Пожиратель миров