The Fillbo (Terrain Restoration Mob)

The Fillbo is a big, friendly nature spirit that looks a like a cross between a boulder and a tree, and there are local variants to go in each biome. It wants to see natural terrain restored, so it will go around replacing dirt, sand, and rocks where they have been dug up, and smooth over damage made from mob griefing by Endermen or Creepers. If you don't want the Fillbo to go near a spot, craft a Warding Totem with some Feathers, Sticks, and Amethyst Shards, or simply place down some Fences to keep them out, they tend to avoid anything made by the player. Thanks to the Fillbo, all natural environmental resources such as Sand, Dirt, or Netherrack can be renewable, as you can gather them without permanently damaging the terrain! These nature-loving mobs are a bit like Wardens, they appear for a minute or so, spawning from certain special sites called "Spirit Paths," and then they return to the earth on their own after doing some fixing. It takes some effort to share the land with these nature spirits, but it's worth it to preserve the natural world.