The Imperial Leviathan is a super-heavy mobile command center and assault transport that uses the same chassis as the massive Squat Colossus and Cyclops war-machines. This monstrous vehicle was supplied to the Imperial Guard as part of the mutual exchange of materials and technologies between the Squat homeworlds and the Imperium. The Imperium uses its Leviathans as gigantic mobile army group command centers for coordinating the vast numbers of men and vehicles found in Imperial Guard Regiments. The Squats employed the Leviathan as a massive troop carrier to transport special "Ironbreaker" Brotherhoods of Squat warriors into combat protected by its multiple Void Shields and metres-thick armoured walls. In essence the Leviathan is a giant land-based Battleship on treads. The Leviathan has enough cargo room to hold over 2 full companies of Guardsmen and all their wargear. The Leviathan even features a rear deck landing pad for Imperial transport craft such as the Valkyrie and Aquila Lander. The vehicle is armed with a wide-variety of weaponry, including eight Battle Cannons and twelve sets of twin-linked Heavy Bolters. The Leviathan's main weapon is an extremely powerful weapon called a "Macro Cannon", it is also known as a Doomsday Cannon. The Macro Cannon is said to be big enough to fit a Leman Russ main battle tank inside of the barrel, and when fired its report is clearly audible from several miles away, while the overpressure shockwave can be felt at similar distances. The Leviathan could be outfitted with Corvus Assault Ramps, turning the massive war machine into a siege tower, allowing its troops to climb onto enemy walls.
The Leviathan is often confused with the Capitol Imperialis command transport, due to the lack of available sources or clarification from Games Workshop the two vehicles will be treated as two separate vehicles. This is fueled by the fact that the Leviathan and Capitol Imperialis' background "fluff" is highly similar.
- Codex: Eye of Terror, pg. 12
- Ork and Squat Warlords (Warhammer 40,000: Epic Supplement), pp. 60, 65
- Warhammer 40,000: Space Marine Battles (2nd Edition), pg. 7
- White Dwarf 283 (UK), pp. 65-69
- His Last Command (Novel) by Dan Abnett