How to add a new element in drupal 7 feed view
Views doesn't provide that functionality, so if you want to configure this via the UI you need to install Views RSS (or another module that provides similar functionality); you don't have another option, apart from writing it yourself.

If you just want to hack something together you can use just manually append your extra elements to the output string, e.g.

function MYMODULE_preprocess_views_view_row_rss(&amp;$vars) {   
  // Add an image.
  $node = node_load($vars['row']-&gt;nid);
  if ($node) {
    $wrapper = entity_metadata_wrapper('node', $node);
    try {
      $vars['item_elements'] .= '&lt;image&gt;' . $wrapper-&gt;field_images[0]-&gt;file-&gt;url-&gt;value() . '&lt;/image&gt;';
    }
    catch (\Exception $e) {
      // No need to recover, just means there's no image.
    }
  }
}


But it's not exactly ideal, better to use the purpose-built module.