onEvent('worldgen.remove', event => {
  event.removeOres(ores => {
    ores.blocks = [ 'minecraft:coal_ore', 'minecraft:iron_ore' ] // Removes coal and iron ore
    ores.biomes.values = [ 'minecraft:plains' ] // Removes it only from plains biomes
  })
  
  event.removeSpawnsByID(spawns => {
    spawns.entities.values = [
      'minecraft:cow',
      'minecraft:chicken',
      'minecraft:pig',
      'minecraft:zombie'
    ]
  })
  
  event.removeSpawnsByCategory(spawns => {
    spawns.biomes.values = [
      'minecraft:plains'
    ]
    spawns.categories.values = [
      'monster'
    ]
  })
})