Titans

The Titans are the mightiest war machines of The Imperium. They are massive, and ancient. They are so old that sometimes even their own crews will worship them. Praising the Adeptus Mechanicus, they cleanse entire worlds under foot and with howling guns. They are a rare model in the tabletop game, while they can be seen in books and in computer games on a somewhat regular basis, or at least mentioned.