Swamp hut

Witch huts, known as swamp huts $$, are generated structures that have the ability to spawn witches and black cats.

Generation
Witch huts generate in swamp biomes. However, they do not generate in the swamp hills biome variant.

Structure
Witch huts consist of a small square "hut" made of spruce planks, with oak log "pillars" extending down to the ground. There is a small platform outside of the hut that could be an entrance; however, it is many blocks above the ground, and there are no stairs that go upwards to the hut. The roof of the witch hut is made up of spruce wood stairs and spruce wood planks.

The inside of a witch hut consists of an empty cauldron, a crafting table, and a flower pot with a red mushroom in it. However, in Bedrock Edition, the cauldron generates with a random potion inside of it in random amounts. These potions include Swiftness, Slowness, Weakness, Healing, and Poison. Water Breathing, Fire Resistance, Night Vision, Harming and Decay seem to have a very low chance of being spawned, also rarely the cauldron contains a splash potion. This is the only way to legitimately obtain Potions of Decay, since the potion cannot be brewed.

Mobs
The 7×9×7 area inside and outside the witch hut can spawn witches continously. No other hostile or neutral mobs can spawn in this area, although passive mobs can. Additionally, one witch and adult black cats always spawns in each witch hut upon chunk generation. It also (mostly) spawns both a witch and black cat.

Trivia

 * The "hut" part of a swamp hut generates on or above the surface, while the wood "pillars" extend down until they reach solid ground. This means that if part of a witch hut is at sea level and another part is on top of deep ground, such as a ravine, the pillars on the deep-ground side go all the way down to the ground.
 * It is possible for swamp huts to generate on top of one another.