[
  {
    "id": "mutant_cow_with_skull",
    "type": "harvest",
    "copy-from": "mutant_mammal_large_leather",
    "extend": { "entries": [ { "drop": "skull_bovine", "type": "bone", "scale_num": [ 1, 1 ], "max": 1 } ] }
  }
]
