Giant Spruce Taiga Hills

The giant spruce taiga hills or redwood taiga hills mutated biome is a modified hills variant of the giant tree taiga that no longer generates since Caves & Cliffs: Part II, and has been removed in Java Edition.

The giant spruce taiga hills was a variant intended to be a more mountainous version of the giant spruce taiga, like all other hills biomes. However, both Java Edition and Bedrock Edition had generation issues.

In Java Edition, due to a likely error in the way terrain height is calculated, there was no difference in the terrain between giant spruce taiga and giant spruce taiga hills. Specifically, the game used internal values known as setBaseHeight and setHeightVariation when generating hills biomes, but these values were the same for both giant spruce taiga and giant spruce taiga hills, resulting in no actual difference between the two. This was the only hills biome in the game with this issue.[1]