How to override an existing theme without subtheming it?
You can call for your css

&lt;?php
function mytheme_preprocess_html(&amp;$variables) {
  drupal_add_css('http://fonts.googleapis.com/css?family=News+Cycle', array('type' =&gt; 'external'));
}
?&gt;


and for your tpl file

&lt;?php
/**
 * Implements hook_theme_registry_alter().
 */
function my_module_theme_registry_alter(&amp;$theme_registry) {
    // Defined path to the current module.
    $module_path = drupal_get_path('module', 'my_module');
    // Find all .tpl.php files in this module's folder recursively.
    $template_file_objects = drupal_find_theme_templates($theme_registry, '.tpl.php', $module_path);
    // Iterate through all found template file objects.
    foreach ($template_file_objects as $key =&gt; $template_file_object) {
        // If the template has not already been overridden by a theme.
        if (!isset($theme_registry[$key]['theme path']) || !preg_match('#/themes/#', $theme_registry[$key]['theme path'])) {
            // Alter the theme path and template elements.
            $theme_registry[$key]['theme path'] = $module_path;
            $theme_registry[$key] = array_merge($theme_registry[$key], $template_file_object);
            $theme_registry[$key]['type'] = 'module';
        }
    }
}
?&gt;