Decaying biom

I have an idea for a biome that’s really rare more rare than the mushroom fields biome 

pit should be a creepy biome that was once like the mushroom fields but decayed overtime giving it a creepy Ora with grey and black particles rising from the ground it should also have a new tree called the twisted tree it would have a wood like oke and have cobwebs spawn on it. 
there should also be a mansion like the woodland mansion but like it’s abandoned. 
please add this to the game.