Wither

Wither is a player-summoned undead boss mob that hovers in mid-air and fires explosive wither skulls at almost any living entity. It is one of the most destructive mobs in Minecraft and the only source of nether stars, which are used to craft beacons.

The wither always drops 1 nether star upon death and grants 50 experience, making it one of the most rewarding boss fights.

The wither does not spawn naturally and cannot be bred. It is summoned by placing four soul sand or soul soil blocks in a T shape and placing three wither skeleton skulls on top. The last skull placed triggers the spawn, after which the wither charges up for 10 seconds before exploding.

The wither is a hostile boss mob that fires wither skull projectiles, which explode on impact and inflict the Wither effect, draining health over time. When its health drops below 50%, it activates "wither armor, " making it immune to arrows and increasing its aggression. The wither destroys most blocks in its path and attacks all mobs except undead ones, making it capable of wiping out entire areas. Due to its massive explosion upon spawning and high durability, players often summon it in underground locations or inside the End to contain its destruction.