[
  {
    "type": "monstergroup",
    "name": "GROUP_ZOMBIE_UPGRADE",
    "monsters": [ { "monster": "mon_zombie_blank", "weight": 30 } ]
  },
  {
    "type": "monstergroup",
    "name": "GROUP_ZOMBIE_BLANK_UPGRADE",
    "default": "mon_zombie_blank",
    "monsters": [
      { "monster": "mon_zombie_blank", "weight": 450 },
      { "monster": "mon_zombie_nullpsi", "weight": 400 },
      { "monster": "mon_zombie_psi_void", "weight": 140 },
      { "monster": "mon_zombie_master", "weight": 10 }
    ]
  }
]
