Eater of Worlds

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 segments (1 head, 48 body, 1 tail) 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 Eater must be killed in order to defeat the entire boss.

Defeating the Eater of Worlds is the only way to obtain Shadow Scales, as well as usable quantities of Demonite Ore. Individual segments drop some of these when killed, with a larger bonus drop upon defeating the entire entity. The Eater of Worlds is immune to the Poisoned, On Fire!, and Cursed Inferno debuffs.

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 and multiple parts.
 * 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.
 * If possible, try to aim for the head or tails of each section, as if they die first, they will not split into more.
 * The Slime Mount makes this fight extremely easy, when summoned in a chasm, he will pin you to the ceiling, allowing the Slime Mount to bounce on his segments once per frame causing massive damage, oftentimes he will kill himself the first time he pins you

History
Dévoreur de Mondes Eater of Worlds Пожиратель миров