Minecraft wiki entry for Caves_%26_Cliffs, associated text: 6 new sub-biomes added and pillager outposts can generate in all of these biomes:
Meadow
Similar to the plains biome but with a colder grass color.
Contains most flowers and lone oak and birch trees.
Generates in plateaus and small mountains next to plains biomes.
Village also can generate in this biome.
Grove
Covered in snow, snow blocks, dirt and powder snow, and is filled with spruce trees.
Rabbits, foxes and wolves spawn in this biome.
Generates in the slopes of a mountain when next to a forested biome.
Snowy slopes
Covered in snow, snow blocks and powder snow.
Goats and rabbits spawn in this biome.
Igloos also can generate in this biome.
Jagged peaks
One of three mountain peak biomes that only generate if the mountain is high enough.
Generates in tall, jagged and pointy peaks.
Covered in snow, snow blocks and stone.
Only goats spawn in this biome.
Frozen peaks
Generates in smoother and usually smaller peaks, but sometimes can generate in taller peaks.
Covered in snow and snow blocks with large patches packed ice and small blobs of ice.
Only goats spawn in this biome.
Stony peaks
Generates in mountain peaks in regions with warmer biomes such as savannas and jungles;
It's mostly covered by stone with strips of calcite.
It doesn't generate snowy slopes or groves in the lower areas of the mountain.
The only mob that spawn in this biome is the glow squid.