Leviathan biomechanoids are a type of living spaceship most commonly found in the Delta Quadrant, in and around the Uncharted Territories. Leviathans were engineered with genetic material derived from the Leviathans of old, powerful and sometimes destructive creatures. The Builders accomplished this and gave them pacifistic souls, worked organic technology into their genetic code, and bade them to be ambassadors of peace. The Builders became gods to this new species of biomechanical vessel.
Leviathan biomechanoids have become wholly unique, practically unrecognizable from the creatures that they are derived from. Each Leviathan grows differently, growing facilities to fit the needs of its crew -- and can grow to immense sizes over their 300 cycle lifespan. Each also has a distinct personality, although their feelings remain unexpressed without the help of a Pilot.
Aside from the Pilot and whatever crew might be aboard, Leviathan biomechanoids are maintained by a number of DRDs -- these small, robotic creatures are remotely operated by either the Leviathan or its Pilot. Leviathans also are capable of many of the systems of other, artificial ships -- atmospheric control, lighting, food storage. Many artificial devices could be attached to a Leviathan, and the Leviathan's systems would interface with almost all of these. However, the Peacekeepers developed some devices which gave them manual control of certain systems within the ship. The Leviathan and its Pilot are aware of and can hear everything that goes on inside of it, save in the Starburst Chamber which collects the energy necessary for a Starburst.
Like other living creatures, Leviathans have certain weaknesses and allergies. Leviathans could develop a form of hay fever when exposed to pollen or spores, such as those emitted by unhealthy Delvians. Similarly, Leviathans are unable to carry the Six Forbidden Cargoes -- such as Novatrin gas and clorium -- due to the side effects the ship might experience.
At some point, one or perhaps several Leviathan biomechanoids were encountered by the zerg and assimilated, giving rise to the strain of zerg known as Zerg Leviathans.
Enslavement
Though Leviathans are often independent creatures, some have been enslaved over the course of history. This was most notably done by the Peacekeepers prior to the Peacekeeper Reformation. Peacekeepers used Leviathans as prison ships, to transport criminals from one penal colony to another.
Peacekeepers maintained their control over Leviathans through massive control collars. These collars allowed the Peacekeepers absolute power over the vessel, essentially rendering the Pilot little more than a janitor. In order to prevent Leviathans from escaping, they would also be implanted with a paddac beacon, which would emit a signal to all nearby Peacekeepers if the control collar was disconnected.
Pilot Bonding
Leviathan biomechanoids can travel without a pilot, or be manually operated by a crew. For the utmost efficiency, and the best means to allow for communication between the crew and the vessel, a Pilot can bond with the Leviathan. This can occur naturally, over the course of a cycle.
Bonding can also occur artificially -- but this causes permanent pain for both the Pilot and the Leviathan.
Reproduction
Little is known of the Leviathan reproductive system or mating rituals -- it is known, however, the female Leviathans can become pregnant, gestate a fetus, and give birth. The pregnancies are a long process, during which crew members are advised to abandon the ship as complications can be very dangerous for those aboard. These complications can include involuntary Starbursts, errors in internal systems such as life support, and erratic DRD behavior.
The embryo is deeply embedded in an internal chamber within the Leviathan, and is guarded and tended to by DRDs. This function overrides all of the other commands a DRD may receive.
Though Leviathans do not ordinarily have weapons, a Peacekeeper research program had intended to breed a type of Leviathan that did possess armaments. Only one such gunship ever existed -- Talyn.
Notable Leviathan Biomechanoids
Source
Leviathan biomechanoids are taken from Farscape. For canon information, please visit the Farscape Encyclopedia Project.