Titans are 100-foot tall robotic war machines from games
workshop's warhammer 40k universe. They appear in their 6mm
scale epic series of games. They come in many varieties, which
vary distinctly between the races. The races themselves are
broadly based on those found in Tolkien's middle earth, but in a
sci-fi setting.  The Titans of the human Imperium are diverse
and powerful engines of destruction. They range in size from the
50 foot tall Warhound scout Titan to the enormous Imperator,
which stands over 150 feet tall, and is the most powerful war
machine ever to be deployed on a planetary surface. All are
powered by plasma reactors, a form of fusion reactor that is
dangerously unstable, and prone to exploding with utterly
devastating consequences when damaged. However, this is the only
way to provide enough energy to drive the myomer-like artificial
muscles needed to move the enormous weight of the titans as well
as power their devastating arsenals. Imperial Titans are
armoured with an extremely hard alloy