The Wither is a boss mob that must be created manually by the player, and it can be spawned in any biome in any dimension.
To summon the Wither, you must use the following materials:
S = Soul Sand or Soul Soil
[S][S][S]
[ ][S][ ]
[ ][S][ ]
Place the skulls: Place the three Wither Skeleton Skulls on top of the T-shape. Placing the final skull will cause the Wither to spawn, accompanied by a large explosion.
Choose a location: Although the Wither can be spawned anywhere, it is a highly destructive and powerful mob. Many players choose to summon it in a sparse or contained area, such as a large open desert or deep underground, to prevent it from destroying structures.