A WordPress function for randomly showing a set number of items from a taxonomy. To use, include <?php random_tax(); ?> in your markup.

WP Random Taxonomy

function random_tax() {

  	$counter = 0;
    $max = 5; // Set max number of items here.
  	$cats ='';
    $categories=get_categories();
    $rand_keys = array_rand($categories, $max);
    foreach ($rand_keys as $key) {
    $cats .= $categories[$key]->term_id .',';
    }
  $args=array(
    'include' => $cats
    );
  $categories=get_categories($args);
    foreach($categories as $category) { 
    	$counter++;
    	if ($counter <= $max) {
      	echo '<a href="">'. $category->name.'</a>, ';
	    } else {
	    	echo 'or <a href="">'. $category->name.'</a> ';
	    }
    }

}