5 Variants
I found in the code, there are 5 variants of giant tree taiga in Bedrock Edition. 1 of them proably unused.
mega_taigaalso known as giant tree taigamega_spruce_taigaalso known as giant spruce taigamega_taiga_mutatedi called this giant tree taiga mountainsmega_spruce_taiga_mutatedalso known as giant spruce taiga hillsmega_taiga_hillsalso known as giant tree taiga hills.
mega_taiga_mutated and
mega_taiga_hills has different water color. Water color in giant tree taiga mountains is #2d6d77, while water color in giant tree taiga hills is #286378, so they actually different biome, but both biome seem to have issue which make them look identical, however i don't have idea as it not listed in this article. ImakerB (talk) 07:56, 2 April 2019 (UTC)
do these biomes contain sweet berries?
Humiebee talk contributions 20:25, 4 August 2020 (UTC)
On Java Edition they actually do. You can test this by yourself by creating a single-biome world with one of these biomes. Here's an example: 1.16.2 Pre-Release 1, Giant Spruce Taiga Hills biome, seed: -6532884426417990740, coordinates: 246 78 139. But it needs to be tested on Bedrock Edition --Geshundra (talk) 20:58, 4 August 2020 (UTC)