Shulker

A shulker is a cubic hostile mob found only in End cities. It hides in its shell to protect itself and blend in with its surroundings, and attacks by shooting homing bullets that inflict Levitation. It is the only source of shulker shells, which are used to craft shulker boxes.

Natural generation

Shulkers spawn during the generation of End cities, which are located on the outer islands of the End. They usually spawn on the walls of the city and on End ships. They do not despawn naturally, even in Peaceful difficulty.

Post-generation

There is a chance for a new shulker of the same color to spawn when a shulker is hit with a shulker bullet (including one of its own ). The following checks need to pass: The hit shulker must have its lid open. (Peeking is technically enough, but fully open is more practical for farming purposes.) The shulker needs to actually take damage and survive. (It just ignores the hit if it is invulnerable to that damage.) The shulker's health needs to be above 50% after taking damage from the hit, otherwise there is a 20% chance for it to attempt to just teleport away "for health reasons". If that happens, the shulker will not attempt to duplicate, even if the teleportation attempt somehow fails. The damage must be projectile damage and originate from a shulker bullet. The shulker will attempt to teleport away (see Teleportation below for details) and must succeed in doing so. A random chance check must pass. The chance to succeed is calculated as 100% minus 20% for each other shulker within 8 blocks of the hit shulker's pre-teleport position. (If there are at least 5 other shulkers this check can never pass.) shulkers also duplicate every time they are killed by a shulker bullet. If the attempt succeeds a new shulker spawns where the old shulker was before it teleported. The new shulker is a completely fresh entity and only copies the original shulker's color.

On death

Shulkers also drop when killed by a player or a tamed wolf.

Behavior

A shulker's shell is similar in color to a purpur block. Inside the shell is a small yellow head with two eyes. Shulkers can be spawned with other colors using the command, as detailed below. Shulkers generally remain stationary, attached to an adjacent block with a full face. However, if the block the shulker occupies becomes something other than air or the shulker finds itself not adjacent to any full face, or the shell cannot fully open (due to solid blocks or entities such as boats or other shulkers), it attempts to teleport away. Shulkers occasionally open their shell for 1–3 seconds. When a target comes within about 16 blocks, it opens fully and shoots guided projectiles that follow its target, called shulker bullets, moving only along the X, Y, or Z axes and leaving trails of white particles. The projectiles can be destroyed by attacking them or blocking them with a shield. If the projectile hits an entity, it does damage and inflicts the Levitation status effect for 10 seconds. This status effect has no effect underwater, while in flight mode, or while riding a mob. The shulker continues firing every 1–5.5 seconds while the target remains in range. If the shulker's target dies with projectiles still in flight, they fall to the ground. Shulkers can attack each other, in which case they shoot fully guided bullets at each other, but are unaffected by Levitation when hit. The normal teleportation habits apply during these battles, and is likely to result in the duplication of more shulkers. When its shell is closed, a shulker has armor points and deflects arrows. When the shell opens, it loses this natural armor and takes damage as normal. When at less than half health, a shulker has a 25% chance of teleporting (as described above) after taking damage. When a shulker is attacked, other shulkers within a 32x20x32 box will target the attacker as well. Shulkers do not take burning damage from lava or fire. They drown in water, but try to teleport away when water or lava flows into the block they occupy. In Peaceful difficulty, shulkers still spawn but do not attack, like piglins and hoglins. Shulkers are treated differently than true blocks. For example, mobs are unable to pathfind around or jump over them, and falling on them from a height does not produce particles. Their spawn egg also does not destroy blocks such as grass. Despite having a full block hitbox, their collision box is not a full block, allowing players to stand on the edge of a block with a shulker on top. Gravity-affected blocks break when falling onto a shulker.

Teleportation

Shulkers can attempt to teleport away for several reasons: The shulker's position may no longer allow attaching to an adjacent block. In this case the shulker attempts to teleport away every tick until it either succeeds or can attach at its current position again. The shulker took damage and is below half health. When taking damage to below half health, the shulker has a 20% chance to attempt to teleport away. The shulker was hit by a shulker bullet and its lid was open. (It might leave behind a new shulker if teleportation succeeds.) When a shulker attempts to teleport away, it will make five attempts to find a position to teleport to. Each attempt checks a random position within a 17x17x17 cube centered on the shulker's current position. The position must satisfy the following criteria for the teleportation attempt to succeed: The position must be above the bottom build limit of the world and within the world border. The position must not contain any non-air block. The block space of the position must not overlap with any block's or entity's hit box. At least one of the adjacent blocks must provide an attachable surface such that the shulker could fully open from that attachment point, i.e. the shulker would not touch any block's or entity's hit box when fully open. Shulkers evaluate the collision box of scaffolding based on their current position, which can result in the shulker teleporting to a position right above a scaffolding block, only to find it invalid and teleport again. When trying to find an attachable surface, the shulker tests adjacent blocks in the following order: below, above, north, south, west, east. It also uses this order when looking for alternative attachment options before teleporting away form its current position if the previous attachment side became invalid.

Shulker bullet

A shulker bullet is a guided projectile that is launched from shulkers. Its shape is similar to a Conduit's power structure, with End stone white coloring on the outside and purple mottling on the inside. As the bullet flies towards its target it spins randomly. It follows the targeted entity along the X, Y, or Z axis and leaves trails of white particles. A shulker bullet that hits a mob or player deals damage and affects it with Levitation for ten seconds. If a shulker bullet hits a neutral or hostile mob by accident, it retaliates against the shulker after its Levitation effect is removed. The shulker's projectiles also have entity data that control its movement. The bullet can be destroyed when it is hit with any item, shot with an arrow, or blocked with a shield. Specifically when attacked by a player using a melee attack, it has a larger hitbox than usual. It is also destroyed upon contact with a block or lava. When a Shulker Bullet is made to go through a portal into another dimension, the bullets continue tracking its target and pathfind to the target's exact coordinates in the new dimension. This works even if the target moves in the other dimension, the shulker bullet keeps tracking its new position. The target has to be kept loaded and if it is not then the bullets fall.