Extreme Hill Biome. Extreme hills is a hilly biome and isn't too rare. Directly to the east of spawn, the extreme hills merge into a shrublands biome. Extreme hills+ is a variation where spruce trees spawn. This biome is common near a taiga biome. To the north of spawn, right over a hill, is a quaint little. This biome has a few variants of extreme hills m, extreme hills+ m, extreme hills+ and extreme hills edge with differences in the terrains. This is because they are both cold biomes.