Minecraft wiki entry for Best_biomes_for_homes, associated text: The land is flat, making building here easier.
Slimes, which will drop slimeballs upon death. Slimeballs are used to craft sticky pistons and slime blocks, making this biome useful for redstone-knowledgeable players.
Blue orchids spawn only in this biome, besides woodland mansions.
Swamp huts will spawn witches continuously. This allows for witch farming, allowing one to farm redstone, sugar, gunpowder, glowstone, glass bottles, spider eyes and, in some cases, pre-brewed potions.
Cauldrons may contain potions in place of water. ‌[Bedrock Edition only].
Black cats spawn in swamp huts.
The hut can also be used as a base once it is adequately lit up.
Fire does not spread far in this biome due to the large areas of water and spread-out trees.
It is a good place for fishing because of all its water.
Fossils have a 1 in 64 chance per chunk to spawn underground and can be a good source of bone meal.
Huge mushrooms generate here. ‌[Bedrock Edition only].
Zombie villagers spawn here wearing unique clothes and can be cured into swamp villagers.
Using clay disks, the player can find diamonds.