The Mushroom Island and Ice Spikes need attention

Over the years mojang has updated almost all of the overworlds biomes in some way or another, sadly though neither the Ice Spikes biome nor the Mushroom Island have gotten any attention even though they have a huge possibility for engaging and fun content, what I mean by this is that we need some new filler for those biomes, make them less empty.

It could range from something as small as some decorations like tiny ice crystals or mushroom bunches, to something bigger like a new formation, mob, structure or even mechanic.

We've already seen some content fitting those biomes from the spin-off games, but even if that isn't on the table just look at the community for ideas, I'm sure everyone has had at least a single idea revolving around those biomes in specific.