IMoO/loot_tables/entities/snow_golem_shear.json

{
  "pools": [
    {
      "rolls": 1,
      "entries": [
        {
          "type": "item",
          "name": "minecraft:carved_pumpkin",
          "weight": 1,
          "count": 1
        }
      ]
    }
  ]
}