Eater of Worlds

The Eater of Worlds is one of the three bosses. It is similar to the Devourer but with much more health and many more segments. It also splits into smaller segments as it takes damage. It appears to be made out of multiple Eaters of Souls that are linked to each other. If you destroy a segment that is neither head nor tail, The Eater of Worlds splits at the spot that was destroyed and continue fighting in more "worms". However, upon splitting damage to each part remains; therefore, trying to maximise damage equally across the entire body will result in the most rapid kill. The Eater of Worlds is either summoned in The Corruption with Worm Food, which is made out of Rotten Chunks (dropped by Eater of Souls) and Vile Powder (made from Vile Mushrooms found in corrupted areas); or by destroying three Shadow Orbs (this may occur multiple times). Worm Food can also be used if there are 500 Ebonstone blocks nearby, regardless of where the Ebonstone is. To defeat this boss, one must destroy every individual segment that makes up its body. The head has 120hp and 0 defense, the body segments have 200hp and 2 defense, and the tail has 300hp and 4 defense. A moving part of it must have at least a head and a tail. If either of those parts die off and there is no body segment to replace it, then the other part that hadn't died yet dies anyway. The Eater of Worlds begins with about 100 segments (needs confirmation). Another way it can die instantly is if, on single player, the player dies at the the same time it is summoned. For example, if a Shadow Orb is destroyed with dyamite, and the explosion kills the player, and the Eater of World spawns when the orb is destroyed, it will be counted as dead. This can be a way to spawn a Dryad NPC before defeating a boss. However, this may not be a glitch, as it could be that the Eater of Worlds is killed by the explosion of the Dynamite. The Eater of Worlds drops Coins, Demonite Ore, Shadow Scales, Shadowscale Armour, Heart Crystals, the Ball O' Hurt, and the Orb of Light. If the Eye of Cthulu is already spawned and the Eater of Worlds is spawned by a shadow orb, the Eater of Worlds dies immediately.

Strategy
A very easy and 'early-in-the-game' (after defeating the Eye of Cthulhu) way to deal with the Eater of Worlds is to have a Vilethorn, a few Healing Potions, a decent amount of health, a decent defense, and a few mana crystals, and simply spam the vilethorn in the direction the boss came out, so that it crosses its path. Alternatively, if you have a decent sword, a lot of healing potions and a decent amount of health and defence, you can just stand ground and as soon as he comes out of the ground attack it (this is not as effective as the vilethorn strategy, though). Another stratagy you may use is if you have a flail, which you can obtain through smashing Shadow Orbs, (The Ball 'O Hurt) and you can fling the flail so that it comes back down to crash through the different segments of the Eater of Worlds. Once with good gear however the Molten Fury and Unholy Arrows (Due to the piercing effect) can quickly take out to boss. The unholy arrows can damage many segments at once and with the Molten Fury the damage can exceed 30 per segment. Before attempting to engage this boss, it is recommended that the player has collected a significant amount of Heart Crystals, at least 6 or 7. The main point of concern during this boss battle is the head, which can deal a sizable amount of damage, but becomes more threatening when the boss is split up into multiple worms, multiplying the damage the player takes. Carrying regular healing potions is recommended, as Lesser Healing Potions are not fast enough to heal at the rate the Eater of Worlds deals damage during the later stages of the battle.Since there is some bugs you can lure the Eater of Worlds to your spawn points and kill it there. Note that as of the 1.0.4 patch the Eater of Worlds is harder to defeat, because his stats were given a raise.

Arena
The classic arena should be an elevated platform, preferably away from any and all NPC houses. Setting up a large amount of platforms for the eater of worlds to tunnel through will allow you to easily strike the head. Setting up any and all spiky balls at the bottom is extremely efficient as well as the use of weapons that pierce. Save damage spikes for the end as when the body breaks into pieces it is easy to be overwhelmed with damage and if your potions are on cool down you may die. Never attempt to fight the Eater of Worlds in the normally cramped confines of a shadow orb area or in corruption as he may knock you down into a chasm. ? To compensate for a high damage, the Head segment sports a low Health and Defense rating. Even though attacking multiple body parts at once is a viable and effecient strategy, players should focus on the Head segment whenever possible, reducing the risk of the Eater of Worlds splitting up into multiple worms and potentially killing the boss faster. Recommended weapons, in order of the stage of the game you would probably have them in, are the following: Shuriken, Broadsword, Ball O' Hurt, Grenade, Flintlock Pistol, Vilethorn, Blue Moon, Blade of Grass, Muramasa, Fiery Greatsword, Space Gun, or Sunfury. In addition, timely use of Dynamite will instantly kill any nearby segments of the Eater of Worlds. Unfortunately, this is a very expensive alternative. Excessive amounts of Spiky Balls can also expedite the death of the Eater of Worlds. Having some sort of tall building, with platform ladder, will make hitting the head easy with any of the ranged weapons as this will make the boss come from straight under you almost every time then be flying in the air to hit for a long duration as well. Shooting downward when at the top of ththumb|300px|left|Eater of Worlds Guideis platform when you hear the digging sound will more than likely get 3-10 hits on the head depending on your weapon. It has been shown, that by jumping at just the right moment, and aiming the Vilethorn straight down, one can deal massive amounts of damage to the Eater of Worlds, and by doing so to the head, helps reduce risk of it turning into many more Eater of Worlds. Another simple yet effecient strategy to defeat Eater of Worlds is by using a Harpoon and Grappling Hook (or Cobalt Shield) and a decent amount of Healing Potions. Once Eater of Worlds is summoned, grapple down onto the ground with your Grappling Hook, then switch out to the Harpoon and aim downward whilst holding down on left-mouse button. Due to the attack pattern of the Eater of Worlds, the Harpoon will deal a large amount of damage to the head and by the second or third pass you will be destroying 2-3 chunks at a time while keeping the Eater of Worlds mostly intact and easy to kill. Always remember to check your health and heal. It might also be a good idea to wear a Band of Regeneration. A good way to kill the Eater of Worlds and you have low-level gear and you have a magic mirror is by when you summon the boss, use the magic mirror. The Boss will follow you back to your spawn point (It may take a moment or two.) So then when you die, the boss will still be there and you can easily claim your coins and still fight him. But be careful, you might put some NPC lives at danger.

You can also fight the Eater of Worlds in the chasms themselves, however this is not recommend this unless you have no method of escaping long chasms quickly. For this strategy, you will need lots of health potions, a strong spammable weapon (such as the Breaker or Ball O' Hurt), a grappling hook or Cobalt Shield (to protect against knockback) and relatively good armor. You must hook onto the side of the chasm and simply spam your weapon. This will strike most of the parts that pass by you, as well as reducing the chance of splitting the Eater into many sections that are full health.thumb|300px|right|A video showing a strategy for dealing with the Eater of Worlds inside chasms.

Bugs
There is a bug where there can be 2, 3, or even more eater of worlds out at once if you use worm bait, then break 3 or more shadow orbs (3, 6 ,9, etc.). Although, when you die, all but one of the eaters go away. A few players have come across a bug where they defeated the Eater of Worlds after they took away most of his body parts but then died. The players got all the items and coins he supposedly dropped though. Most of the claims could be confusion however, as defeated segments do drop some loot (including Demonite Ore and Shadow Scales) as the battle goes on. When the Eater of Worlds runs away after the player has died, a message appears saying that it has been defeated. (If this happens, you are able to get the Dryad NPC to spawn and it should still drop some shadow armour, or it might not). Many people have found that the Eater of Worlds will follow them back to their spawn point in the event of them dying. This may be considered a bug, as this is the only boss which exhibits this behaviour. This makes The Eater of Worlds a lot easier to defeat. It and the first bug could be caused because not the whole boss despawns when you die, making you able to fight this boss anywhere, but it still despawns segments when you die, just not everything. Another rare bug is that the boss will spawn as only a single segment, and nothing else. It will function the same as normal, just very ineffective at killing anyone. A Possible Bug may be that, when building over the Corruption, the boss will be summoned, as if displeased with the bridge. Leading to much confusion and claims of griefing. One very specific bug may happen if the Eater of Worlds is fought in the Underground Jungle. Some of its segments may get "chained/fused" with a Man Eater and stand still. Another bug is that the boss will be summoned on world creation (i.e. Make a world then enter it.). This is most likely caused by deafeating a boss and then immediatley creating the new world.Sometimes when a Meteorite landed and you exit the world and enter it the boss will be summoned.