Witch

Witches are hostile mobs that use splash potions as their ranged weapon. They also use beneficial potions on themselves defensively.

Spawning
Witches can spawn anywhere in the Overworld at a light level of 7 or less.

Witch huts
Every witch hut spawns a witch inside during world generation. Afterwards, only witches will spawn in the 7×9×7 area that is the witch hut. This is the size of the roof and one block over the porch, from one level below the floor of the hut to two blocks above the roof.

Witch huts generated before 1.8.1 have a spawn zone of only 7×9×5. Witch huts spawned on high ground also have a reduced or eliminated spawn zone height.

Villagers
A witch spawns when lightning strikes within 3–4 blocks of a villager and the villager will despawn to give the effect of it turning into a witch.

Drops
When killed, witches may drop glass bottles ($1/8$ chance), glowstone dust ($1/8$ chance), gunpowder ($1/8$ chance), redstone ($1/8$ chance), spider eyes ($1/8$ chance), sugar ($1/8$ chance), and sticks ($2/8$ chance). They make 1–3 drops of 0–2 items each, for a maximum of six items total.

Each level of Looting increases the maximum items dropped by one for each of the 1–3 drops, leading to a maximum of 5 items per drop, and a maximum of 15 items total.

Witches can also drop potions of healing, fire resistance, swiftness and water breathing as an equipment drop if killed while drinking that potion. They drop 5 experience when killed by a player or tamed wolf.

Behavior
Witches use splash potions offensively, and drink ordinary potions defensively. They have a search radius of 16 blocks.

Offense

 * They will throw a potion of slowness if the player is at least 8 blocks away and does not already have the slowness status effect.
 * They will throw a potion of poison if the player's health is at least and is not already poisoned.
 * They have a 25% chance of throwing a potion of weakness if the player is within 3 blocks and does not already have the weakness status effect.
 * If none of the above conditions are true, witches default to using a potion of harming.

Defense
On each AI tick when the witch is not already drinking a potion, it may choose to equip and drink a potion. Drinking the potion takes 1.6 seconds.
 * When under water and lacking water breathing, 15% chance of drinking a potion of water breathing.
 * When on fire and lacking fire resistance, 15% chance of drinking a potion of fire resistance.
 * If damaged, 5% chance of drinking a potion of healing.
 * When more than 11 blocks from a target and lacking swiftness, 43.75% chance of drinking a potion of swiftness.
 * In 1.9, this is a 50% chance.

Witches are 85% resistant to damage from magic, including poison, instant damage, and thorns.

Trivia

 * If a witch hits another witch with a potion, the witch who is hit will become angry and target the other witch, however it is impossible for either witch to kill the other (without help from a player) due to their use of healing potions and their resistance to each other's splash potions.
 * Witches do not utilize the equipment in their huts, but they can be used by players.
 * The odds of a witch dropping the maximum amount of drops possible (6 items total) without a Looting enchantment are 1 in 81 (1.2%).
 * Witches are extremely difficult to kill via suffocation or cacti (though not impossible), due to their frequent use of healing potions.
 * When drinking a potion, a witch's nose will point straight forward.
 * Baby villagers, when struck by lightning, will turn into adult witches.