I think the idea of linking a mob to a block like that is really cool, and the new blocks seem pretty nice (especially that door texture, it looks so good). I do also kinda agree with other people though, the biome itself didn't exactly wow me.
I don't think the problem for me is that it doesn't have much in it, since that can be said for a lot of other biomes. Personally, I'm just not a huge fan of the trees. They're basically just dark oak but de-saturated. Willow trees were mentioned as an inspiration for having droopy vegetation like the hanging moss, so if it was me I would make the trees look more like those. Or at least make them look a little more unique, similar to what they did with mangrove trees.
Overall pretty cool I would say, but we'll have to wait and see what else they decide to add in upcoming snapshots.
