Built by player
The Wither is a floating three-headed mob with a skeletal appearance. It is the second boss mob, introduced in Minecraft during the Pretty Scary Update. It is Minecraft's first player-created mob to be hostile to all living mobs and the player, and is so far exclusive to the PC version.
A Wither can only be spawned in-game using methods similar to spawning utility mobs. By placing soul sand in a T shape (as shown in the image), and putting 3 Wither Skeleton skulls on top of each three upper blocks, the Wither can be created. It cannot spawn when playing on Peaceful difficulty. Similar to all utility mobs, a Wither cannot be created by pistons. Also, the last block placed must be one of the three Wither Skeleton heads; it will not spawn if the final component placed is soul sand. After the Wither is spawned, the sky gets slightly darker. This only occurs in the Overworld.
When spawned, the Wither will temporarily flash blue and grow larger in size as its health bar fills from half to full. While in this state, the Wither cannot move or attack and is immune to all damage. When this state ends, the Wither will create a very large explosion centered on itself, destroying nearby blocks. This explosion does not damage itself, but it will damage any nearby mobs, including the player. To avoid this, move away from the Wither after spawning it.
A ghastly sound is played when the explosion occurs. This sound is not centered around the Wither, instead it can be heard equally from all areas of the map. It can also be heard by other players throughout dimensions. Like creepers, it flashes as a warning before exploding.
 Getting the necessary resources
It can be troublesome to find everything you need to spawn a Wither.
- Wither Skeletons only spawn in Nether Fortresses, and finding one of these involves getting somewhat lucky. To maximize your chance of getting a Wither Skeleton Skull you might want to have a sword of looting which increases the chance of rare drops in monsters. Maximize your Brightness and Render Distance (in Video Settings), and occasionally stop to peer into the distance for the large, straight columns and bridges that indicate a Nether Fortress. Nether Fortresses spawn every few hundred meters along North-South lines, so after checking one North-South line for a few hundred meters and seeing nothing, move East or West and begin scanning North-South again.
- Nether Fortresses are dangerous places, especially for poorly equipped players. The combination of numerous Blazes and regular Skeletons, along with the Ghasts that may opt to bombard you at any given time---all of them ranged attackers---can be deadly. The Wither Skeletons themselves inflict the Wither effect, which is a poison that can kill you. Prepare with iron armor or better, preferably enchanted, a sword, and most importantly, a bow with a steady supply of arrows.
- Once you kill a Blaze or two and receive your first Blaze Rod, and once you find a source of Nether Wart (look near the bottoms of the Nether Fortress's interior staircases), return to the Overworld and craft yourself a Brewing Stand, then a few Potions of Fire Resistance. Their 8-minute duration makes them a worthy potion for Nether Fortress raids.
- Wither Skeletons are dangerous foes, but they cannot pass through a two-block-high doorway. You can use this to your advantage, but it may hinder your efforts to kill enough of them, quickly enough, to account for the final problem:
- Wither Skeletons don't spawn especially frequently, and will drop its skull only 2.5% of the time, and you need three of them (50% chance of looting 3 within 107 Wither Skeleton kills or 120 Wither Skeleton kills required on average). To reduce the required grinding:
- A sword with Looting enchantment improves the odds that a Wither Skeleton will drop its skull.
- While time consuming, you can mine the walls to expand the floor space, giving Wither Skeletons more space to spawn.
- Some Nether Fortresses are better than others for spotting the Wither Skeletons that do spawn. Nether Fortresses with plenty of bridges and columns that are open to the Nether give you much better visibility, allowing you to spot Wither Skeletons further away (they don't spawn very frequently), but you will have to contend with a barrage of Ghast attacks. Conversely, a more sheltered Fortress comprised of hallways would protect you from above, but those same walls reduce your chances of spotting the Wither Skeletons that spawn.
- If you'd prefer a different Nether Fortress, you can find them very easily: Nether Fortresses typically appear on North/South lines, so moving in either of those directions should bring you to another.
To prevent anything bad from happening to any of your things, and to make it easier to battle the Wither, you should do the few things listed below.
- Go a good distance away from your shelter, as the Wither can seriously damage any structures near it.
- To keep your things safe from the Wither, dig about twenty-five blocks deep, and make plenty of space to spawn it and then run before the explosions begin.
- You will probably want a source of light. Torches are almost perfect for light, but most of them will likely be destroyed by the Wither. To make it easy to see while fighting the Wither, using a Potion of Night Vision will be perfect.
In addition, there are measures that can be taken to make the fight considerably easier
- If you've gotten to The End and killed the Enderdragon already, you may want to consider fighting the Wither in The End. If built and then run away from, the Wither should attack Endermen instead of the player, and the Endermen will fight back. When this happens, you can get the Wither to half health, grounding it so the Endermen can finish it off, or let it float above and gun down Endermen indefinitely, which, among other things, generates a considerable quantity of free ender pearls.
- If you're still having trouble defeating the Wither, consider building an Iron Golem to assist your fight. Its high health and damage will relieve the player of some of the burden.
The Wither is hostile to the player and all mobs except undead mobs (Skeletons, Zombies, Zombie Pigmen, Wither Skeletons and other Withers). When provoked by a skeleton or another Wither, they will only remain hostile toward each other for a moment before returning to friendly status. If spawned in the End, it will prefer to attack any nearby Endermen, but will attempt to pursue and attack the Ender Dragon if there are no nearby targets.
The Wither can become very dangerous quickly. Upon noticing a mob, the Wither attacks them with a projectile called the “Wither Skull”. Wither Skulls move slowly and inflict a status effect called "Wither"(Wither II from the boss) on Normal and Hard difficulties. This effect is similar to Poison, except that it can kill the player and turns the health bar black, making it difficult to tell at a glance how many hearts are still full. Although some may consider this cheating, it is possible to modify the withering hearts texture to stand out better. When attacking a Player, the Wither will fly above it, making melee attacks difficult.
Each head fires independently, allowing a Wither to attack up to three different mobs at the same time. Withers need at least 5 block high airspace to fit. They can not be trapped and suffocated in smaller rooms. Every few seconds, the Wither will break any block that comes into contact with it, except Bedrock and End Portal Frames. These blocks are unbreakable by any conventional means, each having a blast resistance of 18,000,000, though in creative mode it is possible to break them.
The Wither's boss health bar is only shown when a player is looking in a direction of a Wither, and it can also be seen through walls when the player is looking in the Wither's direction. When reaching half health, the Wither will gain the "Wither Armor" effect, which makes it immune to arrows and potions, as well as having a visual effect surrounding it, similar to that of a Charged Creeper. While in this state, the Wither will only fly if angered. If calm, it simply hovers and is unable to jump up 1 block. When angered by the player, the Wither will fly at the same height as the player. Like other undead mobs (zombies, skeletons, etc.), the Wither is harmed by Potions of Healing and healed by Potions of Harming. It also regenerates over time (1 () every 20 ticks (1 second)).
 Wither Skull
The Wither shoots Wither Skulls, which look like extra heads of itself launched as projectiles, and can keep up a fairly constant barrage of them. Upon contact, a Wither Skull will explode, although with a blast radius much smaller than that of TNT or a Creeper. If the explosion of a Wither Skull damages a mob or a player on Normal or Hard difficulty, it inflicts the Wither effect, draining their health and turning their hearts black. If the skull hits a mob or player directly, it will also heal the Wither for 5 () health. There are two types of Wither Skulls: a fast moving black one, and a slow moving blue one. Both have an explosion power of 1, the same as Ghast fireballs; however, the blue skull has special properties.
The black Wither Skull has a normal blast, which cannot break blocks with a blast resistance above 20. Thus, cobblestone and other Ghast-proof blocks will resist this blast. The blue Wither Skull is shot primarily if the difficulty is set to normal or above, when the Wither is idle, meaning the player is not within its aggro range. On average, 0.1% of the shots by the main head (when the wither has a target) are Blue Skulls as well; thus even if the wither is targeting someone, it still has a chance of shooting a Blue Skull. Although the blue Wither Skull nominally has the same explosion strength as the black Skull, it treats all blocks (except bedrock and End Portal frame) as having a blast resistance of no more than 4. This makes it much more destructive to the terrain, and lets the Wither blast away obsidian traps or shelters from a distance. The Wither can even unintentionally blast at faraway objects with the Blue Wither Skull, because if it misses, the shot will continue going until it hits a target, and may even go on forever. A Blue Wither Skull may be seen later if it flies into an unloaded chunk, and that chunk is entered by the player after killing the Wither. Note that unless the Blue Wither Skull was shot by the main head during its attack on a target (~0.1% chance), the Blue Wither Skull would be sent in a random direction.
Because the Wither inflicts a great deal of damage, the best equipment for combat is a diamond sword (Preferably enchanted with Smite. The best sword for the fight is one enchanted with Smite V, or Sharpness V if you anticipate outside mob intrusion.) Instant Health II Splash Potions, Strength II Potions, one or two enchanted golden apples, a Bow (Preferably enchanted with Power, the best bow for the fight would be Power IV or V, Punch II, and Infinity I) and Diamond Armor (Protection IV protects from the withering effects. The 'Thorns' enchantment may also be an advantage, but it is expensive and not as important as proper protection). Make sure to bring about a stack or two of arrows if you don't have the Infinity enchantment. Fire enchants do not work on the Wither. Smite is better than Sharpness, but a high level Sharpness should be good enough.
Bringing or summoning allies (Wolves, Snow Golems and Iron Golems) may or may not be advantageous: on one hand, they provide a diversion and will cause damage to the Wither: on the other hand, they may die easily because of the explosions and get affected by the Withering effect, healing the boss far more than they damage him. If you create the Wither in a small and completely enclosed underground area that isn't too large (three blocks tall), three Iron Golems are sufficient to kill one without aiding them.
Spawn the Wither, and quickly run away as far as possible, putting a large distance between you and the Wither. Do not stand near the Wither when it is growing into its normal size. It will create a massive explosion when it is finished, much larger than that of TNT or a (charged) Creeper. When it is finished, walk back and shoot at the Wither, and occasionally use your Instant Health II Splash Potions and at some point, eat your Enchanted Gold Apples. When the Wither drops to 50% health, use your Strength II Potion and hit the Wither with your diamond sword until the Wither is defeated. This is a very effective way to beat the Wither, defeating it in less than five minutes with not too much struggle.
An extremely easy way of beating the Wither is to dig out a 10x10 by 3 tall room and spawn 30 or so Snow Golems. The Golems act as a target for the Wither, as well as attacking it. Accompany this with your best sword (preferably with the Smite enchantment), armor, and potions and you can beat him in under a minute taking little or no damage.
A tactic that is relatively easy to pull off is to dig down near bedrock, and dig a long 1x2 tunnel (Longer than 30 blocks). At the end of the tunnel, construct a small room. Spawn the Wither in this room, then run back into the tunnel. Occasionally pop out and shoot an arrow or two at the Wither. As the Wither crunches its way towards you, just walk backwards through the tunnel. Once the Wither has reached its "Armor" stage, jump out and begin hitting it with a diamond sword. As long as you frequently throw down splash potions of instant healing, you should be able to survive even with iron armor.
A somewhat more complicated yet very enjoyable variant of this tunnel strategy (doubly so when you manage to kill the Wither using it) is to rig the tunnel you constructed with TNT. You could, for instance, build a tunnel as illustrated by the figure below; the idea behind this is that you can anticipate when the boss will crunch his way to a point sufficiently close to a pair of TNT blocks you've placed, and if you're accurate, you can have the TNT explode at that very instant, dealing a lot of damage. Be sure not to place the first pair of TNT right next to the room in which you will spawn the Wither, as the initial explosion would just destroy these. The drawbacks of this strategy are that it can be difficult to tell when to pull the levers; if you're too fast, the TNT will not have the desired effect. If you're too slow, the Wither will simply destroy the TNT prior to its detonation. In addition, you might need a lot of TNT to completely kill the Wither, and thus you'll have to dig out a long tunnel. Therefore it is strongly advised that you still use a bow (and a sword when the "Armor" stage has been reached) in the sections of the tunnel where there's no TNT to do the hard work. Also, if you don't have enough TNT, be sure to dig out an extra tunnel as an extension of the TNT-rigged one, so as to finish the Wither off with arrows/swords should needs be.
A simple TNT-rigged tunnel. The arrow indicates the way you will be moving with the Wither in pursuit
A more advanced tactic that is very rewarding would be to construct a cobblestone generator-powered grid above the player, spawn the Wither about 15 blocks away, and stand under the grid. The Wither will fly towards the player, but it would be kept at the edge of the grid, constantly being pushed back by the cobblestone which is generating faster than what the Wither can break. This allows the player to stand still and shoot the Wither without retaliation, until the Wither is at half health, where it will fly towards the player through the grid, allowing the player to easily kill the Wither with a sword. In addition to that, the player can rig dispensers about 15 blocks away to periodically shoot splash potions of health, which heal the player and damage the wither. This tactic is explained in greater detail in this video.
It is also possible to kill the wither with a fully automatic machine, requiring no combat from the player. The most conventional design suffocates the wither with a cobblestone generator, as demonstrated in this video or this video.
Another easy way of killing the wither is shown in this video.
|Icon||Achievement||In-game description||Prerequisites||Version restriction||Xbox points earned||Internal ID (PC Only)||Scoreboard name (PC Only)|
|The Beginning?||Spawn the Wither||The End.||PC||N/A||unknown||spawnWither|
|The Beginning.||Kill the Wither||The Beginning?||PC||N/A||unknown||killWither|
|1.4.2||12w34a||The Wither was introduced into the game, but it does not spawn naturally. Left unfinished by Jeb and hidden in the code, it was discovered through the presence of its skin in the /mobs/ folder. Withers could only be spawned with edited monster spawners, mods, or hacks.|
|12w34b||When its health is taken down to half, it will gain Wither Armor, making it immune to arrows.|
|Projectile firing rate and movement speed increased.|
|At PAX, Dinnerbone revealed that it would be possible to spawn Withers by arranging Wither Skeleton skulls in some way.|
|1.4.2||12w36a||Wither now can be spawned by arranging Soul Sand in a T shape and placing three Wither Skeleton skulls on top.|
|Wither now drops 20 experience and a nether star on death.|
|12w37a||Wither will make a massive explosion upon its creation after its health is fully charged.|
|When there are no targets, the Wither will sometimes shoot blue Wither Skulls, which move slower and can destroy any block besides bedrock.|
|12w38a||Added sound when Withers break blocks.|
|12w42b||Experience dropped is increased from 20 to 50 points.|
|1.4pre||Various new sounds for the Wither.|
|1.4.4||1.4.3pre||The oversight where Withers despawned in Peaceful difficulty has been fixed. Before this update, attempting to spawn the Wither in Peaceful resulted in a waste of Soul Sand and skulls.|
|Withers can no longer destroy End Portals, which are supposed to be unbreakable.|
|1.5||13w05a||Withers cannot ride minecarts anymore.|
|1.7.2||13w37a||Added achievements for spawning and killing the Wither.|
Issues relating to "Wither" are maintained on the issue tracker. Report issues there.
- The Wither is 4 blocks tall, 3 blocks wide, and 1 block thick, however its collision box is only 4 blocks tall, 1 block wide, and 1 block thick.
- If the Wither has nothing to shoot at, it will stay still, moving very rarely.
- The Wither can be damaged by the explosions of its own projectiles.
- Dying from the Wither effect has its own death message: [playername] withered away.
- Withers are unaffected by fire and lava, similar to Nether mobs. The Wither will not take drowning damage if somehow submerged in water for too long.
- The Wither will take block suffocation damage. After the first tick of damage, it will destroy the blocks suffocating it if mobGriefing is turned on. However, it still can't destroy bedrock.
- The command
/give <player> minecraft:spawn_egg <amount> 64will give the desired amount of mob eggs set to spawn a Wither, but nothing happens when the player attempts to use it.
- There is a hint to creating the Wither. Sometimes, when a painting is placed, it spawns a painting showing the soul sand+ Wither skeleton formation in order to spawn a Wither.
- It is possible to just walk forward constantly and the Wither's skulls won't hit the player, as it is constantly adapting its speed to its target.
- The Wither armor glows red when it gets hit.
- The screen will visibly darken when you look at the Wither.
- The Wither drops 50 experience, only twice the max drop for the Magma Cube (25 exp), but far behind by the Ender Dragon.
- The Looting enchantment does not affect the Wither's Nether Star drop.
- The Wither attacks all living mobs, including living hostiles like Creepers, Spiders, Ghasts, Endermen, and the Ender Dragon.
- Withers have 100 ( × 50) more health than the Ender Dragon, making it the mob with the most health points.
- Unlike Ghast Fireballs, Wither Skulls cannot be hit or shot with an arrow to be redirected. If they’re shot with arrows, they will explode on contact, destroying the skulls and arrow.
- In many foreign language translations, Wither is translated to a portmanteau of "Skeleton" and "Cerberus". This is due to the fact that it has three heads.
- The Wither can still see you when you are using the invisibility potion and will not turn invisible when hit by an invisibility potion.
- Wither explosions are not affected by the "Deadening effect" that water has on TNT and creepers.
- Because it is undead, Splash Potions of Healing will damage it, but Splash Potions of Harming will heal it.
- The Wither will not target undead mobs (Zombies, Skeletons, etc.) and vice-versa, but one will attack the other if hit by a stray shot. 
- If the Wither is fighting passive mobs and an Iron Golem is present, the Wither will stop and start attacking the Iron Golem. Probably because the Iron Golem's purpose is to defend from hostile mobs.
- What looks like the vertebral column of the Wither is not exactly centered relative to the other part of its body: it is shifted by a half pixel on its right side.
- In Spanish (España) the Wither will be called Eustaquio and its own kill message will be translated to "[playername] sufrió una witherhostia" (Translated as "[playername] got witherpounded"). It's yet unknown if it is a joke, or an oversight by Mojang.
- Even though the Wither is constantly adapting its speed with the player, players on horses can outrun the Wither.
- Withers are one of the four mobs that give a debuff to the player. The other three being the Wither Skeleton, the Cave Spider and the Witch.
- If you use a name tag to rename the Wither, the boss meter will use that name instead of "Wither".
- The Wither will spawn above a ceiling if it's too short.
- The Wither has more health than the Ender Dragon, but the Ender Dragon flies faster than the wither which makes it harder for the wither to hit.
- Unlike the Wither Skeleton, the Wither's eyes and mouth are both white
- Despite having 3 heads, only the center one will look at the player.
- Withers can break obsidian.
- The wither armor does not use the "wither_armor.png" file, instead it uses the sprite of the mob itself. It is unknown if this is a bug or if it is intentional.
- The Wither is actually smaller than it is when fighting. Because it is actually growing, you can use "/summon" to spawn a Wither with a very high "Invul" tag (such as 100000) to make the Wither appear huge. Note that this Wither will be upside down, but can be given a "CustomName" tag with the name of "Dinnerbone" or "Grumm" to turn it upside down.
A bunch of Ender Dragons flying around, as well as a few Withers, some with Wither armor doing battle with the Ender Dragons.
- http://www.twitch.tv/pax2/b/330745811 (at 3:57:47)