bedrock-samples/resource_pack/render_controllers/guardian.render_controllers.json

{
  "format_version": "1.10.0",
  "render_controllers": {
    "controller.render.guardian": {
      "geometry": "Geometry.default",
      "materials": [ { "*": "query.is_ghost ? Material.ghost : Material.default" } ],
      "textures": [ "query.is_elder ? Texture.elder : Texture.default" ]
    }
  }
}