Starcraft II: Heart of the Swarm
The leviathan is a massive airborne zerg breed.
Leviathans are the zerg’s equivalent of a capital ship. They are classified as class-10 zerg flyers and are the largest in terran records, even larger than a mothership,, though dwarfed by an arkship, and have been referred to as “moon sized. “Measurements taken by the Terran Dominion have placed the leviathan at being around 6.7 killometers long. Leviathans possess interior evolution chambers, can store tens of thousands of zerg strains within their interior chambers, and are capable of deep-space travel and can land on planets. They can operate in temperature conditions of near absolute zero and are capable of traveling through warp space. Sacs may be dropped from leviathans. Because of the sheer size, wraith sensors are unable to penetrate deep enough to see the leviathans’ interior spaces.
Leviathans are typically armed with a daunting array of bio-weapons. Giant, hollow tentacles resembling those of the spine crawler can grab smaller craft or puncture the hulls of larger ships and insert zerg boarding parties. Most leviathans can launch bile swarms at their enemies, and unleash powerful bio-plasmid charges that deal devastating damage to their targets. Furthermore, coccoons birthed within the leviathan are capable of mutating into mutalisks and brood lords.
Leviathans were once space-borne creatures before being infested by the zerg, turning them into armored carriers. They were used by the Swarm in war as early as the fall of Aiur, and at least one was present at Char in the Second Great War. During the Battle of Char, zerg broods in leviathans were on their way to the planet when Kerrigan was de-infested. These broods were then scattered or destroyed. Upon her return to the Swarm, Kerrigan’s new base of operations was a leviathan. It would fly to different planets and land on them at her direction.
During the Swarm invasion of Korhal, Arcturus Mengsk ordered any and all Dominion troops from across the sector to return to the capital world. A number of leviathans under the command of Broodmother Kilysa formed a blockade to prevent the Dominion Fleet from entering the system.
Leviathans were used by Kerrigan when the Zerg Swarm entered the Void through Ulnar in the last stages of the End War.
Years later, feral leviathans were lured to Tyrador IX via psi-emitters from the Defenders of Man. By 2512, leviathans continued to be a core part of the Zerg Swarm’s stellar arsenal.