Skeleton

Skeletons are undead, ranged hostile mobs equipped with bows. Strays are variants of skeletons that only appear in certain biomes

Spawning
Skeletons can spawn almost anywhere in the Overworld at a light level of 7 or less. In the Nether, they can also spawn in nether fortresses at a light level of 7 or less in place of a wither skeleton.

Spiders have a 1% chance spawn with a skeleton riding them, creating a spider jockey.

Skeleton riders spawn when a skeleton trap is triggered by a player. The skeletons ride on skeleton horses and are equipped with enchanted bows and iron helmets, and have damage immunity for 3 seconds after spawning.

Skeletons are 1.99 blocks tall.

Monster spawners
Skeletons also spawn from spawners found in dungeons.

Stray


80% of skeletons spawned directly under the sky in ice plains, ice mountains, and ice plains spikes biomes will be strays. The 1% of spiders spawned in those biomes which end up spawning as a spider jockey also have an 80% chance to be a stray spider jockey.

Strays behave much the same as normal skeletons do. However, they shoot tipped arrows that inflict for 30 seconds on any target that it hits. Despite shooting slowness arrows, strays themselves are not immune to slowness.

Strays make similar noises to Skeletons, but with the addition of an echoing effect.

In addition to normal skeleton drops, strays have a 50% chance to drop a tipped arrow of Slowness. With the Looting enchantment, this chance increases to $2×level+1/2×level+2$, which comes to $3/4$ for level I, $5/6$ for level II and $7/8$ for level III.

Drops
Skeletons drop 0-2 bones and 0-2 arrows upon death. Any picked-up equipment has a 100% chance of dropping and will drop with the same damage level it had when picked up. When killed by a player any naturally spawned equipment (including the bow) has a 8.5% (9.5% with Looting I, 10.5% with Looting II and 11.5% with Looting III) chance of dropping and will drop with a random durability. A skeleton will drop its head if killed by a charged creeper's explosion.

Skeletons drop 5 experience when killed by a player or tamed wolf, +1-3 extra experience if the skeleton has equipment.

Halloween
On Halloween, skeletons have a 22.5% chance of spawning wearing a pumpkin and a 2.5% chance of spawning wearing a jack o'lantern. If these skeletons are killed using a tool enchanted with Looting, there will be a chance equivalent to the level of Looting used to drop the pumpkin or jack o'lantern, up to a maximum of a 3% chance of a drop.

Behavior


Skeletons spawn in dimly lit areas, and will burn in sunlight. When skeletons are nearby, their presence is indicated by the intermittent harsh rattling sound of their bones. Skeletons will chase any player they see within 16 blocks, and will climb stairs, navigate mazes, and traverse other complex obstacles in order to get within shooting range. When they are within 8 blocks of the player with a clear line of sight, they will stop chasing and start shooting the player with arrows. They will strafe during the process, and will retreat to safe range if the player comes too close to them. If the player moves more than 16 blocks away from the skeleton, it will cease pursuit. The detection range of skeletons is reduced to half of their normal range (8 blocks) when the player is wearing a skeleton mob head. Skeletons can attempt to avoid damage from the player by continuously circling around them while shooting at them.

The skeleton's accuracy is based on the difficulty. Skeletons have an "error" of 10 on easy, 6 on normal, and 2 on hard. This is compared to the player's "error" of 1. When their target is closer, skeletons shoot faster, but do less damage. To account for gravity, skeletons aim 0.2 blocks higher for every block horizontal they are from the target.

If a skeleton's arrow hits certain hostile mobs, that mob will then attack the skeleton the same way it would attack the player, given it was not hit by the player first. If a skeleton is attacked by another mob (usually another skeleton), it may attack that mob, reorienting on the player once that mob is dead.

When wielding anything but a bow, they will move at about the player's walking speed. If spawned with no weapon at all (by using commands) a skeleton acts like a zombie (though faster), coming at the player with arms outstretched and damaging the player by touching them.

Skeletons are also able to climb ladders, but only when forced to, as their AI does not handle ladders in a special way.

Like zombies, skeleton burning occurs at dawn when the sun is 15 degrees or greater above the ground, unless the skeleton is either in shade, water, or wearing a helmet. If not wearing a helmet, they will attempt to find shade or water to keep from burning. Unlike zombies, which will always chase the player if they see one, skeletons will not exit the shade area even if attacking a player. Burning skeletons have a 50% chance of shooting flaming arrows if the raw regional difficulty is 3 or greater.

Skeletons holding tipped arrows in their off hand will shoot that type of arrow; these arrows are not consumed.

Skeletons run from wolves, as wolves attack and chase skeletons. When skeletons are safe from sunlight, they will shoot at any wolves that attack it. Skeletons will also shoot at iron golems. Creepers killed by a skeleton's arrow will drop a music disc.

Armed and armored skeletons


Like zombies, some spawned skeletons can pick up dropped items from the ground, and if those items happen to be armor, pumpkins, jack o'lanterns or mob heads they will equip them, and if weapons or tools, the skeleton will use them as a melee weapon.

Skeletons spawn already-armed with bows, which may also be enchanted. The chances of that event are listed below and are taken from the game's code. If a skeleton spawns wearing multiple pieces of armor, the armor will never be mismatched (i.e. all pieces will be made of the same material).

If a skeleton does spawn with armor, the chances of specific armor are as follows:

The chances of it being of a particular material are:

Skeleton armor is not damaged from most damage sources, which means it cannot "wear out" the way player armor does. Helmets (not blocks like pumpkins) on skeletons can wear away and break if the skeleton is exposed to daylight or has an anvil or other falling block dropped on its head.

If a skeleton has a bow and a sword is given, it will drop the bow (with the same chance as if killed with Looting I) and start using the sword. If a skeleton has a sword or bow in their hand, and one of a better type or with better enchantments is given, they will drop the existing weapon (with the same chance as if killed with Looting I) and start using the better one. Any skeleton that spawns with equipment (picked-up items don't count) will give 1–3 extra experience points per item. Note that skeletons seem to always drop their equipment in pocket edition.

Data values
Skeletons have entity data associated with them that contain various properties of the mob. Their entity ID is.

Trivia

 * If alerted to a player's presence, skeletons can fire arrows backwards, occasionally hitting themselves.
 * Skeletons cannot see the player through glass, fences, or other transparent blocks.
 * When holding a sword, skeletons are actually much faster than zombies and sprint at you as a wither skeleton. This is because they share the same Entity ID as a wither skeleton.