Reference
Biome Spawn Reference
Which mobs spawn in each biome, how often and in what group size, read from the game's own data for your version. Look up a biome, or a mob to see everywhere it spawns. Java Edition 1.17 to 26.3.
67 biomes
Plains
Overworld · minecraft:plains · Java 26.3
Monsters9 mobs
Hostile mobs. They spawn in the dark.
Animals6 mobs
Passive mobs. Most are placed when the chunk is made, then spawn slowly.
Ambient1 mob
Bats.
Underground water1 mob
Water in caves.
Spawn rules here
- Chicken, Cow and Pig: temperate variant.
Want a mob that is already there? Build its command in the Mob Builder.
What changed in 26.3
Spawn changes from Java 26.2, in 1 place.
- New biome.
Mob spawns in every biome, Java 26.3
Each percentage is that mob's share of the spawn attempts for its group in that biome. Monsters and animals are separate groups, so they never compete with each other. Change the version at the top of the page to see another.
Overworld
| Biome | Monsters | Animals | Water and caves |
|---|---|---|---|
| Badlands | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 26%, Pig 22%, Chicken 22%, Cow 17%, Armadillo 13% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Bamboo Jungle | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Ocelot <1% | Sheep 7.1%, Pig 5.9%, Chicken 12%, Cow 4.7%, Parrot 24%, Panda 47% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Beach | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Turtle 100% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Birch Forest | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 30%, Pig 25%, Chicken 25%, Cow 20% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Cherry Grove | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Pig 20%, Rabbit 40%, Sheep 40% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Cold Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | – | Ambient: Bat 100%; Water animals: Squid 60%, Nautilus 40%; Underground water: Glow Squid 100%; Fish: Cod 50%, Salmon 50% |
| Dappled Forest | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 25%, Pig 21%, Chicken 21%, Cow 17%, Rabbit 8.3%, Fox 8.3% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Dark Forest | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 30%, Pig 25%, Chicken 25%, Cow 20% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Deep Cold Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | – | Ambient: Bat 100%; Water animals: Squid 60%, Nautilus 40%; Underground water: Glow Squid 100%; Fish: Cod 50%, Salmon 50% |
| Deep Dark | – | – | – |
| Deep Frozen Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | Polar Bear 100% | Ambient: Bat 100%; Water animals: Squid 33%, Nautilus 67%; Underground water: Glow Squid 100%; Fish: Salmon 100% |
| Deep Lukewarm Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | – | Ambient: Bat 100%; Water animals: Squid 53%, Dolphin 13%, Nautilus 33%; Underground water: Glow Squid 100%; Fish: Cod 21%, Pufferfish 13%, Tropical Fish 66% |
| Deep Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | – | Ambient: Bat 100%; Water animals: Squid 14%, Dolphin 14%, Nautilus 71%; Underground water: Glow Squid 100%; Fish: Cod 100% |
| Desert | Spider 19%, Zombie 3.7%, Zombie Villager <1%, Skeleton 9.7%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Husk 16%, Parched 9.7% | Rabbit 92%, Camel 7.7% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Dripstone Caves | Spider 16%, Zombie 16%, Zombie Villager <1%, Skeleton 16%, Creeper 16%, Slime 16%, Enderman 1.6%, Witch <1%, Drowned 16% | – | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Eroded Badlands | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 26%, Pig 22%, Chicken 22%, Cow 17%, Armadillo 13% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Flower Forest | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 27%, Pig 23%, Chicken 23%, Cow 18%, Rabbit 9.1% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Forest | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 27%, Pig 22%, Chicken 22%, Cow 18%, Wolf 11% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Frozen Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | Polar Bear 100% | Ambient: Bat 100%; Water animals: Squid 33%, Nautilus 67%; Underground water: Glow Squid 100%; Fish: Salmon 100% |
| Frozen Peaks | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Goat 100% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Frozen River | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | – | Ambient: Bat 100%; Water animals: Squid 100%; Underground water: Glow Squid 100%; Fish: Salmon 100% |
| Grove | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Wolf 7.7%, Rabbit 62%, Fox 31% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Ice Spikes | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 3.9%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Stray 16% | Rabbit 91%, Polar Bear 9.1% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Jagged Peaks | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Goat 100% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Jungle | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Ocelot <1% | Sheep 13%, Pig 11%, Chicken 22%, Cow 8.8%, Parrot 44%, Panda 1.1% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Lukewarm Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | – | Ambient: Bat 100%; Water animals: Squid 59%, Dolphin 12%, Nautilus 29%; Underground water: Glow Squid 100%; Fish: Cod 33%, Pufferfish 11%, Tropical Fish 56% |
| Lush Caves | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | – | Ambient: Bat 100%; Underground water: Glow Squid 100%; Fish: Tropical Fish 100%; Axolotls: Axolotl 100% |
| Mangrove Swamp | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 14%, Creeper 19%, Slime 20%, Enderman 1.9%, Witch <1%, Bogged 5.8% | Frog 100% | Ambient: Bat 100%; Underground water: Glow Squid 100%; Fish: Tropical Fish 100% |
| Meadow | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Donkey 20%, Rabbit 40%, Sheep 40% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Mushroom Fields | – | Mooshroom 100% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Ocean | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Drowned <1% | – | Ambient: Bat 100%; Water animals: Squid 14%, Dolphin 14%, Nautilus 71%; Underground water: Glow Squid 100%; Fish: Cod 100% |
| Old Growth Birch Forest | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 30%, Pig 25%, Chicken 25%, Cow 20% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Old Growth Pine Taiga | Spider 19%, Zombie 19%, Zombie Villager 4.6%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 20%, Pig 17%, Chicken 17%, Cow 13%, Wolf 13%, Rabbit 6.7%, Fox 13% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Old Growth Spruce Taiga | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 20%, Pig 17%, Chicken 17%, Cow 13%, Wolf 13%, Rabbit 6.7%, Fox 13% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Pale Garden | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | – | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Plains | Spider 19%, Zombie 17%, Zombie Villager <1%, Zombie Horse <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 26%, Pig 22%, Chicken 22%, Cow 17%, Horse 11%, Donkey 2.2% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| River | Spider 16%, Zombie 15%, Zombie Villager <1%, Skeleton 16%, Creeper 16%, Slime 16%, Enderman 1.6%, Witch <1%, Drowned 16% | – | Ambient: Bat 100%; Water animals: Squid 100%; Underground water: Glow Squid 100%; Fish: Salmon 100% |
| Savanna | Spider 19%, Zombie 17%, Zombie Villager <1%, Zombie Horse <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 23%, Pig 19%, Chicken 19%, Cow 15%, Horse 1.9%, Donkey 1.9%, Armadillo 19% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Savanna Plateau | Spider 19%, Zombie 17%, Zombie Villager <1%, Zombie Horse <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 18%, Pig 15%, Chicken 15%, Cow 12%, Horse 1.5%, Donkey 1.5%, Armadillo 15%, Llama 12%, Wolf 12% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Snowy Beach | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | – | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Snowy Plains | Spider 19%, Zombie 17%, Zombie Villager <1%, Zombie Horse <1%, Skeleton 3.9%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1%, Stray 16% | Rabbit 91%, Polar Bear 9.1% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Snowy Slopes | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Rabbit 44%, Goat 56% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Snowy Taiga | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 20%, Pig 17%, Chicken 17%, Cow 13%, Wolf 13%, Rabbit 6.7%, Fox 13% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Sparse Jungle | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 21%, Pig 17%, Chicken 34%, Cow 14%, Wolf 14% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Stony Peaks | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | – | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Stony Shore | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | – | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Sulfur Caves | Sulfur Cube 32%, Creeper 16%, Skeleton 16%, Slime 8%, Cave Spider 6.4%, Zombie 16%, Enderman 3.2%, Witch <1%, Zombie Villager 1.6% | – | Ambient: Bat 100% |
| Sunflower Plains | Spider 19%, Zombie 17%, Zombie Villager <1%, Zombie Horse <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 26%, Pig 22%, Chicken 22%, Cow 17%, Horse 11%, Donkey 2.2% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Swamp | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 14%, Creeper 19%, Slime 20%, Enderman 1.9%, Witch <1%, Bogged 5.8% | Sheep 24%, Pig 20%, Chicken 20%, Cow 16%, Frog 20% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Taiga | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 20%, Pig 17%, Chicken 17%, Cow 13%, Wolf 13%, Rabbit 6.7%, Fox 13% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Warm Ocean | Drowned <1%, Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | – | Ambient: Bat 100%; Water animals: Nautilus 29%, Squid 59%, Dolphin 12%; Underground water: Glow Squid 100%; Fish: Pufferfish 38%, Tropical Fish 63% |
| Windswept Forest | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 27%, Pig 22%, Chicken 22%, Cow 18%, Llama 11% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Windswept Gravelly Hills | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 27%, Pig 22%, Chicken 22%, Cow 18%, Llama 11% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Windswept Hills | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 27%, Pig 22%, Chicken 22%, Cow 18%, Llama 11% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Windswept Savanna | Spider 19%, Zombie 17%, Zombie Villager <1%, Zombie Horse <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 23%, Pig 19%, Chicken 19%, Cow 15%, Horse 1.9%, Donkey 1.9%, Armadillo 19% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
| Wooded Badlands | Spider 19%, Zombie 18%, Zombie Villager <1%, Skeleton 19%, Creeper 19%, Slime 19%, Enderman 1.9%, Witch <1% | Sheep 25%, Pig 21%, Chicken 21%, Cow 17%, Armadillo 13%, Wolf 4.2% | Ambient: Bat 100%; Underground water: Glow Squid 100% |
Nether
| Biome | Monsters | Animals | Water and caves |
|---|---|---|---|
| Basalt Deltas | Ghast 29%, Magma Cube 71% | Strider 100% | – |
| Crimson Forest | Zombified Piglin 6.7%, Hoglin 60%, Piglin 33% | Strider 100% | – |
| Nether Wastes | Ghast 30%, Zombified Piglin 60%, Magma Cube 1.2%, Enderman <1%, Piglin 8.9% | Strider 100% | – |
| Soul Sand Valley | Skeleton 28%, Ghast 70%, Enderman 1.4% | Strider 100% | – |
| Warped Forest | Enderman 100% | Strider 100% | – |
The End
| Biome | Monsters | Animals | Water and caves |
|---|---|---|---|
| End Barrens | Enderman 100% | – | – |
| End Highlands | Enderman 100% | – | – |
| End Midlands | Enderman 100% | – | – |
| Small End Islands | Enderman 100% | – | – |
| The End | Enderman 100% | – | – |
Other
| Biome | Monsters | Animals | Water and caves |
|---|---|---|---|
| The Void | – | – | – |
Structures with their own spawns, Java 26.3
Inside these structures the game uses this list instead of the biome's. "None" means nothing of that group spawns there.
| Structure | Group | Where | Spawns |
|---|---|---|---|
| Ancient City | Monsters | Its whole area | None |
| Animals | Its whole area | None | |
| Ambient | Its whole area | None | |
| Water animals | Its whole area | None | |
| Underground water | Its whole area | None | |
| Fish | Its whole area | None | |
| Axolotls | Its whole area | None | |
| Other | Its whole area | None | |
| Nether Fortress | Monsters | Its rooms | Blaze 36% (group of 2–3), Zombified Piglin 18% (group of 4), Wither Skeleton 29% (group of 5), Skeleton 7.1% (group of 5), Magma Cube 11% (group of 4) |
| Ocean Monument | Monsters | Its whole area | Guardian 100% (group of 2–4) |
| Underground water | Its whole area | None | |
| Axolotls | Its whole area | None | |
| Pillager Outpost | Monsters | Its whole area | Pillager 100% (group of 1) |
| Swamp Hut | Monsters | Its rooms | Witch 100% (group of 1) |
| Animals | Its rooms | Cat 100% (group of 1) | |
| Trial Chambers | Monsters | Its rooms | None |
| Animals | Its rooms | None | |
| Ambient | Its rooms | None | |
| Water animals | Its rooms | None | |
| Underground water | Its rooms | None | |
| Fish | Its rooms | None | |
| Axolotls | Its rooms | None | |
| Other | Its rooms | None |
How to use the Biome Spawn Reference
Every biome has its own list of mobs it can spawn, with a weight for each. This reference reads those lists from the game's data for your exact version, works out each mob's spawn chance, and shows the structures that replace them (from 1.18.2, when they became data) and, from 1.19, the variants a biome gives.
Quick steps
- 1Pick your version at the top of the page
- 2Choose By biome and tap a biome to see everything that spawns there
- 3Or choose By mob to see every biome a mob spawns in, best chance first
- 4Tap a mob or a biome in the results to jump to it, and copy the link to share it
Example use cases
- Finding the best biome for a mob farm, or one where a mob cannot spawn
- Hunting a rare mob or a variant, like a particular wolf or a warm frog
- Checking what changed in a new version before you update a world or a server
Tips
Monsters, animals, fish and bats are separate groups: a high share means a lot within its own group, not overall
Most animals are placed when a chunk is first made, so new animals appear slowly after that
Inside a structure such as a swamp hut or a Nether fortress, its own list replaces the biome's
A mob in the list still needs the right light and blocks under it to appear
Frequently asked questions
What mobs spawn in plains in Minecraft?
In Java 26.3 plains spawn Spider (19%), Zombie (17%), Zombie Villager (<1%), Zombie Horse (<1%), Skeleton (19%), Creeper (19%), Slime (19%), Enderman (1.9%) and Witch (<1%) as monsters, and Sheep (26%), Pig (22%), Chicken (22%), Cow (17%), Horse (11%) and Donkey (2.2%) as animals. The percentage is each mob's share of the spawn attempts for its group.
Where do mooshrooms spawn in Minecraft?
In Java 26.3, mooshrooms spawn naturally in Mushroom Fields.
Where do axolotls spawn in Minecraft?
In Java 26.3, axolotls spawn naturally in Lush Caves.
Where do frogs spawn in Minecraft?
In Java 26.3, frogs spawn naturally in Mangrove Swamp and Swamp.
Where do pandas spawn in Minecraft?
In Java 26.3, pandas spawn naturally in Bamboo Jungle and Jungle.
Where do parrots spawn in Minecraft?
In Java 26.3, parrots spawn naturally in Jungle and Bamboo Jungle.
Which Minecraft biome has no hostile mobs?
In Java 26.3, Deep Dark and Mushroom Fields have no monsters in their spawn list, so no hostile mob spawns there on its own. Spawners, raids and patrols can still bring them.
Do witches only spawn in witch huts?
No. Witches are in the monster list of most Overworld biomes, as a rare pick. Inside a swamp hut the game swaps that list for the hut's own, which holds only Witch, so nothing else hostile spawns there. That is what makes witch farms work.
How does Minecraft decide which mob spawns?
Every biome has a weighted list for each mob group (monsters, animals, water animals, bats and so on). When the game tries to spawn a group, it picks one entry at random, more often the heavier ones, then checks that mob can stand there and that the light is right. A mob with weight 100 in a list that adds up to 500 is picked one time in five.