Leviathans were regarded as amazing and wonderful creatures, in that they were bio-mechanoid ships that could move freely among the stars. They shared much of the same attributes as artificially constructed starships, including internal atmospheres, command centers, living quarters, workshops, and hangar decks. However, no two Leviathans were completely the same. As they grew, their internal facilities developed to suit the needs of their crew.
A Leviathan was essentially a spaceship with a personality. They had their own thoughts, feelings, emotions and so on, which were often relayed through the Pilot, if one was present. Leviathans did most of their communications through non-verbal means, and the ability to do this extended to their Pilots as well ("Beware of Dog") though the Builder Kahaynu once gave Moya the ability to speak verbally to her passengers. ("Look at the Princess - I Do, I Think", "Look at the Princess - The Maltese Crichton")
Leviathans were mainly seen as ships, though it is clear they had their own personality, their culture, and even their own gods, known as the Builders. (Episodes 2.10 to 2.12 - "Look at the Princess" trilogy)
The Builder Kahaynu did not state that it was the Builders who created Leviathans, since anyone could create a machine, and even imbue it with intelligence. He did mention, however, that it was the Builders who gave Leviathans their soul. Leviathans were made to be ambassadors of peace (2.11 & 2.12 - Look at the Princess 2 & 3) and the Builders frowned upon their exploitation by the Peacekeepers and their gunship plans – Moya was nearly decommissioned until Zhaan proved herself responsible enough not to exploit Moya's ability to reproduce gunships. ("Look at the Princess" trilogy)
The bio-mechanical part of Leviathans seemed to constitute of DRDs, which were small service robots. These could be controlled remotely by either the Pilot or the Leviathan itself. Another was the various life-support mechanisms the Leviathan could produce for creatures inside it, such as air and light, and also compatibility with defense screens and being able to interface with other systems, such as food freezing systems. Some systems could be fitted without the Leviathan's jurisdiction, such as prison cell doors which had controls in the command chamber, but out of reach of the Leviathan's control.
Leviathans were incredibly large creatures. A fully matured Leviathan could grow many times the size of an infant. The average Leviathan lived for three hundred cycles. (Episodes 2.10-12 - Look at the Princess trilogy)
The interior of a Leviathan was not all blood and vital organs. Chambers and corridors which DRDs used to traverse the ship and which can be made habitable for other organisms filled the inside. There were also various shafts for DRD travel, air flow, and flow of the Leviathan's bodily fluids, as well as chambers made purely for filtering air.
They could develop a form of hayfever. Pollen inside the Leviathan could weaken the hull and impede navigation. ("Home on the Remains")
Leviathans permanently stayed in space where they move with ease. They did not often visit the surface of planets, where the gravity and their own weight made it very hard to escape. ("I, E.T.") A game concocted by young Leviathans, though, involved Leviathans diving towards a planet and seeing how far they could go before they have to pull out. Though not really designed to do so, a Leviathan could dive underwater, but the differences in pressures meant they would take on water. ("The Peacekeeper Wars")
Peacekeepers had various ways for enslaving Leviathans, but the most common was the control collar. A huge device was fitted on the Leviathan itself which controlled its propulsion, guidance and so on, and resulting in death to the Leviathan if it should attempt Starburst. In such cases Pilots were usually used as well to keep the Leviathan's internal systems working and operate the DRDs, basically acting as a janitor while the Peacekeepers control the ship through the control collar. ("Premiere") A device placed inside the Leviathan, known as the paddac beacon, emitted an alert signal if a regular confirmation signal is not heard from the control collar, implying it has been removed. This signal informed any Peacekeepers nearby that there is an uncontrolled Leviathan in the area. ("I, E.T.")
With Leviathans being used primarily as cargo ships, there were six items that they could not carry, more commonly referred to as "The Six Forbidden Cargoes". One such one was Novatrin gas, which was able to dissolve flesh from living creatures. ("The Ugly Truth") Another is referred to as chlorium, that "is an atmospherically induced isotope of trillium." ("I, E.T.")
Pilot Bonding Edit
It is not yet known how the natural bonding occurred between a Leviathan and Pilot.
Leviathans also utilized a feature called "Starburst". This was a defensive maneuver that came naturally to them, and was a method of extremely fast travel where the Leviathan rode an energy stream until they were pushed out at random. ("Through the Looking Glass") This consumed a lot of energy which the Leviathan had to replenish before Starbursting again. Leviathans must be healthy before they can Starburst, with Moya once being unable to Starburst after the crew were forced to set her interior on fire to stop an infestation of metal-eating parasites. Moya was known to perform a reverse Starburst, going backwards instead of forwards ("The Locket") or an extended Starburst, which had a much longer range than a normal Starburst. ("Bad Timing") Both of these maneuvers were quite risky and could cause death to the Leviathan. Starbursts could completely invalidate all navigational data.
Leviathans had no weapons for interstellar warfare, and were mainly used by Peacekeepers as transport vehicles. Inside the ship, the DRDs were vigilant and ready to destroy intruders should the need occur. The crew of Moya found themselves under attack from the DRDs at one point. ("They've Got a Secret") Pregnant Leviathans were known to kill intruders who tried to board them and they developed a reputation for being dangerous. The DRDs could also act as the Leviathan's and Pilot's eyes inside the ship.
Transport pods were small, unarmed crafts that were the standard issue Leviathan cargo and personnel transports. They were capable of atmospheric flight, and fast enough to allow interplanetary travel. While idle, they were stored in transport hangars.
Leviathan transport pods were bioships. A Leviathan could grow new transport pods as needed, and as such they were somewhat expendable. Unlike the Leviathans themselves, the transport pods were not intelligent, or even sapient enough to fly on their own. They required at least one crewmember to pilot them.
If a transport pod was kept away from its Leviathan host for an extended period of time, it would usually go inactive and become unusable. This was not always the case, displayed when Aeryn Sun, aged 160+ cycles, managed to pilot an aged transport pod back to Moya ("The Locket") Perhaps the odd effects of the center halo Moya was trapped in kept the transport pod and Moya connected.
Very little is known about Leviathan reproduction or mating rituals. Leviathans females could become pregnant, gestate a fetus, and give birth. The pregnancy was usually a long and complicated process. The child was conceived via a biological process and the embryo nested in one of the innermost chambers (usually on utility tiers which were inaccessible to the passengers). The embryo was tended to and defended by DRDs. This was an instinctive behavior that can override the usual DRD control channels. The DRDs could attack crew members who got too close to the developing child if they were perceived as a threat.
Side effects of pregnancy included involuntary Starbursts, malfunctioning of life support and various other internal systems, as well as erratic DRD behavior. Crews of pregnant Leviathans had to be prepared for many discomforts and were often advised to abandon the ship for the remainder of her pregnancy.
Peacekeepers had a Leviathan breeding research program attempting to produce a hybrid Leviathan warship that could take orders directly from a Sebacean captain (rather than interact with the crew via a bonded pilot). They successfully artificially impregnated Moya, who gave birth to the first (and only) hybrid Leviathan ship: Talyn. All other breeding attempts resulted in the death of the mother and the child, attributed to the fact that all other attempts were with enslaved Leviathans wearing control collars.
Talyn had a very powerful external retractable gun turret and wall-mounted security guns on the inside, and didn't need a Pilot to control him; however Talyn's architecture still offered a vestigial Pilot's den. He could bond with a Sebacean pilot via a special neural implant at the top of the spine. Talyn chose to bond with rogue Peacekeeper captain Bialar Crais; however – using the Pilot's den – Talyn was able to temporarily, yet successfully, bond with Stark while Crais was incapacitated.
Leviathans normally lived for over 300 cycles. When old age approached, they tried to travel to the sacred Leviathan burial space to rest among the remains of other members of their species. Bonded Pilots died along with their host, though their natural lifespan was over 3 times longer than that of a Leviathan. Although it was theoretically possible to "transplant" a Pilot to another ship, most Pilots did not even consider it as an option. The Pilot society forbid young individuals to bond with Leviathans until they reached a certain age (Moya's Pilot was an exception).
The sacred Leviathan burial ground was in a remote area of the Uncharted Territories, and the exact location was a secret.
Leviathans had many predators, from Peacekeepers who tried to enslave them, to the Grudeks, who harvested their Toubray fibers. The Patriqu-ro, a race of ship builders that competed with the Builders, also ranked among the enemies of Leviathans. They had even employed the services of an alien, Mu-Quillus, who created a siren star to bait and, ultimately, destroy Leviathans. ("Meltdown")