Upon death, a wither skeleton can drop coal, bones, a stone sword and rarely (1 in 50 chance) their head, but the chances increase if The Looting enchantment is applied to the weapon. Three wither skeleton heads and four soul sand/soul soil blocks are required in order to spawn the Wither.
Wither skeletons will only spawn within Nether fortresses as of the 1.4 pre-release. It's assumed that they follow the same rules for spawning as blazes, which will only spawn naturally, and not from a spawn where the pack spawn is selected within a nether fortress. From this pack spawn, the mobs can be spawned in, close to or even inside the fortress. In Bedrock Edition, they will also spawn when a Wither is below half health, in which 3-4 will spawn. A light level of 7 is required for a wither skeleton to spawn.
Unlike regular skeletons, wither skeletons carry swords instead of bows. In appearance, they are black and almost as tall as the Enderman. Being a Nether mob, they won't burn in sunlight and they won't die if in lava or set on fire.
If a player is hit by a wither skeleton, a player will be infected with the wither effect, which will slowly drain their health. Unlike poison, however, it can kill a player. Using a skeleton spawn egg in Creative mode in the Nether has a 75% chance of spawning a wither skeleton instead of a regular skeleton.
Like regular skeletons and strays, wither skeletons will avoid wolves, and are considered undead mobs. They are immune to poison, healed by splash potions of harming, and harmed by splash potions of healing. Wither skeletons will attack piglins and vice versa.
The wither skeleton is taller than the regular skeleton and is slightly shorter than the Enderman, making it the third tallest hostile mob in the game. It almost looks charred, possibly because of fire and lava, or because of the wither effect's color. It holds a stone sword instead of a bow.
- Getting into a two-block tall space will prevent the wither skeleton from pursuing a player, making them stuck and an easy target.
- Using a bow and arrows will allow a player to pick off the wither skeleton from a distance.
- When cornered, it's best to use a shield in combat to prevent getting hit due to the wither effect the wither skeleton gives.
- In Creative mode, a spider egg has a 0.8% chance of spawning a wither skeleton jockey.
- Like Skeletons, Wither Skeletons can neither swim nor drown.
- Wither skeletons have a chance of spawning left-handed, like normal skeletons.
- If added via commands, Wither Skeletons can use Bows, even in their offhand.
- Wither Skeletons with Bows will prioritize using their Bows in their offhand if they have both a sword and a bow equipped, despite them spawning with a sword naturally.
- Wither Skeletons equipped with bows will shoot flame arrows in daylight, despite the fact that they are immune to burning in the sunlight. This is because Skeletons and Wither Skeletons share the same behavior.
- When on Normal and Hard difficulty, the wither skeleton can inflict the wither effect on a player.
- In some editions, wither skeletons spawn from The Wither when the latter is at half-health.