Overgrown Biome/New Creatures

Minecraft should make a new overgrown biome, maybe with jungle or some new tree everywhere, where there is good loot, new structures, and leaves everywhere, and maybe some new mob that can spit out saplings, like a slime, but deeper green and doesn't move as much. It can be called seedlings and/or seeders, with the adults a block and a half tall and produce a random sapling every few minutes, but the babies about as tall as a slab and produce one oak sapling every three minutes. These new creatures could be farmed and if killed could drop a seed to the trees of the overgrown biome, because maybe the new trees don't drop seeds/saplings from their leaves. Maybe this could also add a chance for new villagers, with tents and tipis on the ground and pods and houses high on the trees, and these villagers can climb ladders and go up and down from the above and below buildings.