{
  "feature": {
    "type": "minecraft:fossil",
    "config": {
      "max_empty_corners_allowed": 4,
      "fossil_structures": [
        "minecraft:monster_room/default",
        "minecraft:monster_room/default",
        "minecraft:monster_room/default",
        "minecraft:monster_room/default"
      ],
      "overlay_structures": [
        "minecraft:monster_room/zombie",
        "minecraft:monster_room/zombie",
        "minecraft:monster_room/skeleton",
        "minecraft:monster_room/spider"
      ],
      "fossil_processors": "trek:mossify_50_percent",
      "overlay_processors": "trek:mossify_50_percent"
    }
  },
  "placement": [
    {
      "type": "minecraft:rarity_filter",
      "chance": 200
    },
    {
      "type": "minecraft:count",
      "count": 1
    },
    {
      "type": "minecraft:in_square"
    },
    {
      "type": "minecraft:height_range",
      "height": {
        "type": "minecraft:uniform",
        "max_inclusive": {
          "absolute": -1
        },
        "min_inclusive": {
          "above_bottom": 6
        }
      }
    },
    {
      "type": "minecraft:biome"
    }
  ]
}