Turbine's official Dungeons & Dragons Online website has been updated with a twelfth monster profile, this time detailing the Iron Golem. Once again, concept art of the creature is included, but you'll need to be a member of the game's forums to view the article. Check it out:
The iron golem, most powerful of constructs: fearless, unrelenting, well nigh indestructible. Standing over 12 feet tall, this lord of metal towers over pretenders at that title. It is almost totally immune to magic and essentially immune to weapons and physical attacks that are not made of adamantine. It is an unstoppable juggernaut. The warforged can claim sentience, even cherish a belief in their own souls and the possibility of an afterlife. The iron golem has neither of these things, and cares not at all. Indeed, should a warforged encounter an iron golem one-on-one, the warforged should expect to quickly put his belief in an afterlife to the test.