Ghast

Ghasts are very large, jellyfish- or ghost-like mobs that float through the air and shoot fireballs from their mouths. They are lava and water resistant. Their bodies are 4 blocks tall and 4 blocks wide with 9 tentacle-like limbs hanging from the bottom and eerie-looking eyes. Even though the Ghasts are dangerous and aggressive, they appear to be crying and have patches under their eyes which are actually tear stains. Ghasts are able to spawn above any non-transparent block in the Nether that is not in a nether fortress, as long as there is sufficient space (at least a 4*4*4 space, with the base centered above a solid block), and the difficulty is not Peaceful.

Behavior
Ghasts normally float around the Nether with their eyes and mouth closed and periodically make high-pitched, cat- or infant-like sounds. They open their red eyes and mouth when attacking. They make a chirp-like noise when shooting and scream pitifully when taking damage. The sounds that Ghasts make have a minimum intensity regardless of their distance, so they often sound closer when they are actually far away. Ghasts let out a death rattle upon being killed - similar to the death cries that Zombies, Endermen, Blazes and Spiders use when killed.

Ghasts have an extreme attack range, explosive attack power, and mobility. Unlike most other aggressive mobs, the Ghast does not have a pursuit mode - it does not attempt to draw closer to the player when at long range (and likewise is not particularly likely to float away). Compared to other mobs, the Ghast has a very long search range and can target a player up to 100 blocks away. When the player comes within about sixteen blocks, the Ghast will open fire and attempt to gain altitude.

Ghasts will not fire at the player without a line-of-sight &mdash; this can be blocked by glass, glass panes, leaves, Nether portals, vines, iron bars, sugarcane, both types of fences, and cobwebs &mdash; making safe scenic paths through the Nether a viable possibility. When not moving, Ghasts within firing range will face the player, giving the impression that they can see through transparent materials. Ghasts can draw a line-of-sight through curtains of lava, and their fireballs can pass through it, meaning players near a pillar of lava can be struck without seeing the source. This appears to happen even if the player would otherwise be obscured if not for the lava; for example, if the player is within a structure of netherrack, the firing and explosions of Ghasts can sometimes be heard. However, the Ghast can "cancel" its fireball while shooting if the player moves behind an obstruction or builds one.

Ghasts may also be set on fire, but fire and lava don't actually damage them. A similar effect is seen with Zombie Pigmen and Wither Skeletons. When a Ghast is caught in lava, its movement is impeded, and can then be easily targeted with arrows. At around 23:09 in this video, a Ghast impeded by a lavafall can be seen, and again, but closer and for a longer period of time, at 23:59.

Ghasts may drop a ghast tear when killed, but this can be hard to collect &mdash; because it is a flying mob, the tear may fall into lava or an inaccessible area. Ghast tears are a positive potion ingredient for Regeneration potions, and are very valuable on most servers with economies, so Ghast tears are well worth obtaining.

It's worth noting that the way the Looting enchantment currently works, you'll get the extra drops as long as you're holding a sword with Looting while you kill something, regardless of if you actually used the sword to kill it. What this means is that if you, for example, shoot an arrow at a ghast, you can still get the Looting effect as long as you switch to a Looting-sword before it hits.

Ghast fireball


The Ghast's fireball attack has a straight trajectory unaffected by gravity and an unlimited or very long range limited in practice only by the confines of the Nether's caverns. Fireballs do not track the player once fired, and can be deflected if the player hits them with an arrow or melee attack. Their explosions can often be heard without the impact being seen. At close range, it is one of the most powerful mob attacks in Minecraft, fourth only to the explosion of a Creeper, the melee attack of an Iron Golem, and the explosion of a Wither skull. A direct hit from point blank range will deal hearts of damage but damage decreases with distance and is less if the player is simply caught in the blast radius. The projectile is fairly slow and easy to dodge but is fired with perfect accuracy by the ghast. When two Ghast fireballs collide, one is deflected to a random direction while the other explodes upon impact. Ghast fireballs can also be deflected hitting it with anything. Blocks are also set on fire by the explosion.

If a Ghast's fireball hits a portal or hits close to it the portal will be closed, requiring re-ignition.

The minimum block resistance required to absorb all blast force of the Ghast's fireballs is 20.17.

Video
Note: At 0:39 in the video, it is stated that the player can only kill a Ghast with an arrow, or with deflecting a fireball. However, this is not true. It is possible to kill a Ghast with anything, if you can only reach it. Usually, this would be when the Ghast has spawned under a fairly low ceiling, so it can't fly away.

It is also possible to use a fishing rod to pull a Ghast in close, then hit it. This can be extremely useful if done using a sword enchanted with Looting.

Trivia

 * In Creative Mode, you can go inside of a Ghast by falling through the top of it or flying up underneath it. If you stand on top of the head you will see inside of it.
 * Ghasts can ride minecarts (like most other mobs).
 * Ghasts can cause other mobs to attack it, but the Ghast will never target other mobs; it will only target the Player. This is because they have no pursuit mode. For the same reason, they cannot be "provoked" in Creative mode.
 * Unlike other mobs, Ghasts will fly away when being hit in Creative mode.
 * If the player is able to fly inside an aggressive Ghast, the mob may die of shooting fireballs at itself. They are also careless about shooting at short range where they will be hurt by the blast.
 * It is possible to kill Zombie Pigmen by deflecting Ghasts' fireballs at them. It is also possible to deal a critical hit on a fireball.
 * Due to their low health, Ghasts can be killed in 2 or less hits by a stone sword and above.
 * Ghasts are the largest naturally occurring mob by volume - they are eight times as big as the largest natural variation of slime, but Ender Dragons are longer. Nevertheless, they have less health than most—the only hostile mobs with less are Silverfish, and small and tiny slimes.
 * If a Ghast is trapped in a 1-thick cube, it will shoot fireballs through the cube. This is because all mobs that shoot, spawns the projectile one block in front of it to prevent the projectile from hitting the mob.
 * On rare occasions, a Ghast will spawn in such a way as to see through blocks (usually trapped on all sides in a tight area). When this happens and the Ghast has 'line of sight' through those blocks, it will launch a fireball in the player's direction. This can be extremely confusing, causing the player to brace for impact, even if no Ghast can be seen.  If the player stays in one place, the fireballs can eventually bore a hole through netherrack to blow up the player.
 * Some rooms in Nether fortresses are big enough for a Ghast to spawn in. However, this Ghast will likely be trapped, as there may not be an exit large enough for it to fit through.
 * If a Ghast is killed, any fireball the Ghast has launched will disappear.
 * In SSP there are a couple of glitches that can strand "frozen" fireballs:


 * If the player leaves the Nether while a fireball is still flying through the sky, it will be motionless in the sky if the player returns.
 * Similarly, if the player instead saves and quits to title, switches into Peaceful mode, then reopens the world, the Ghast will disappear, but the fireball will slowly stop.
 * In either case, when hit (say, with an arrow), it will react as normal and fly in the opposite direction from where it was hit.
 * The player can not place blocks near the frozen fireball, because it is an entity with a hitbox, unlike items.
 * The only 4 ways that Ghasts can be in the Overworld are Spawn Eggs, an edited mob spawner, the /summon command, or a Ghast going through a Nether Portal.
 * If you tweak a mob spawner to spawn Ghasts, the model inside the spawner is larger than the frame.
 * When aiming with an enchanted bow (with at least power I) at full charge, it will kill a Ghast in 1 hit.
 * C418 revealed in an AMA on Reddit that the Ghast sounds are taken from his pet cat, which he makes when disturbed while sleeping.
 * Ghasts are apparently not undead, since the Wither attacks them.
 * In the game files, there is a sound file called "affectionate_scream", that is currently unused.
 * Though Ghasts cannot see through sugarcane, it is impossible to do it in the Nether because sugarcane needs water to be placed and you cannot place water using a water bucket (though you can place it using a world editor like McEdit).
 * Using the /summon command, one can spawn a Ghast fire ball without external editors, along with editing explosion power
 * By modifying the explosion power, it can be noted that as the explosion power increases, the craters become more cubical than "round," and at extreme strengths, the explosion does not actually create bigger craters, but rather a large grid of deep and shallow holes and trenches, which might be thought of as 'cracks' in the ground.
 * However take note that any explosion power more than 100 will cause Minecraft to fail for bad pcs. It is recommended you do not summon any fireball with an explosion power of more than 1000.
 * Two Ghasts are featured in the LEGO set "Minecraft Micro World - The Nether", along with a Zombie Pigman.
 * Ghasts, along with Guardians, are the only hostile mobs that flee when attacked.