Leviathans

"They're pretty much like shapeshifters, really, but more into eatin' folk and nothin' can kill 'em."

- Bobby Singer, on the Leviathans

The Leviathans, also called the Old Ones, were some of God's very first beasts, and thus pre-date angels, humans, and the soul itself. Being too destructive, God created Purgatory and locked them inside. They were inadvertently released when Castiel opened Purgatory and absorbed all the souls inside in order to defeat Raphael. They first appear in the Season 7 premiere "Meet The New Boss" and serve as the season's primary antagonists.

Characteristics
''"Long before God created Angel and Man, he made the first beasts: The Leviathans." - Death''

According to Death, the Leviathans were among God's earliest, if not His very first, creations. Unfortunately, the beasts proved to be too destructive (to the point of wanting to eat everything) so He locked them away in Purgatory - which Death reveals as being specifically created to contain the Leviathans. Death describes them as "clever" and "poisonous". He also says he personally found them "entertaining".

In spite of their chaotic nature, it is established that the Leviathans have some sort of hierarchy, with several of them taking orders from their leader, Dick Roman. Under Roman's command, there are head Leviathans who in turn have authority over other Leviathans. It is Roman's orders that send several Leviathans to hunt down those in their group who have been feeding indiscriminately and to deal with the Winchesters and their allies. It seems that the higher-ranking Leviathans have an easier time controlling their hunger.

Their true form hasn't been fully shown, but they seem to take on a serpent-like shape while under water. A leviathan doesn't necessarily need a vessel to function, because they functioned quite well when there wasn't anything to possess, but it does help. Once a vessel is taken, the Leviathan is able to shapeshift without taking a new one. When in a host, they can dislocate the jaw and reveal a mouth full of large teeth and a twin-forked tongue.

Powers and Abilities

 * Invulnerability: There is no known way for a hunter to kill a Leviathan, and they heal quickly from physical injuries. The only way to cripple one is to remove its head and hide it so that it can't reattach to its body. Borax is extremely caustic to most Leviathans, but not deadly.
 * Regeneration: Leviathans can heal wounds they receive and can even reattach their heads when cut off. Their leader Dick Roman can heal much faster than an average Leviathan.
 * Possession: Leviathans are able to take over a human body, much like demons can.
 * Shapeshifting: Leviathans are able to shapeshift to match anyone whose DNA they have access to. This also allows them to access their form's memories. Unlike earlier shapeshifters in the series, they have the ability to mimic a human's specific clothing as well, making it even easier to impersonate people.
 * Superhuman strength: Leviathans are immensely strong, even being able to overwhelm angels, and demons.
 * Immortality: The Leviathans are immortal, through having an ageless lifespan, meaning that they do not age at all. A Leviathan is immune to death by natural causes and aging.
 * Unnamed black blood manipulation: It is shown by Edgar that at least high ranking leviathans are able to instantly kill angels by injecting them with the black substance that seems to act as their blood. Victims of this ability exibit black blood coming out of the place the Leviathan has injected them in as well as their mouths and causing their blood vessels to turn black and seemingly larger.
 * Immunity: Edgar was unaffected by an attempted counterattack by an Angel, shortly before killing the angel.

Weaknesses

 * Hunger: Leviathans are constantly hungry, which can lead them to making mistakes, such as becoming distracted or revealing their true form. Leviathans are also a cannibalistic species; the only known way (currently) to permanently destroy a Leviathan is for one to eat another, or for one to eat itself (a punishment known as "bibbing").
 * Witchcraft: It's unknown if witchcraft can kill a Leviathan, but it can stun and weaken it for a short period.
 * Decapitation: By removing a Leviathan's head, the Leviathan is rendered unable to act. However, the head must also be hidden to keep it from reattaching.
 * Borax - Borax is extremely caustic to Leviathans, weakening them and eating their flesh much like Holy Water does to demons. The Leviathan boss, Dick Roman, is somewhat immune to the chemical and finds it "bracing".
 * Bone of the Mortal dipped with the blood of the fallen: It i revealed the bone of a mortal dipped with the blood of the fallen (fallen angel, ruler of hell and father of fallen beasts) can kill the Leviathans.

Season 7
When Castiel cracked open Purgatory and imbibed the souls found in there, he also unknowingly absorbed the Leviathans. After some time, they began manifesting in him and asked him to let them out.



Due to their uncontainable power, Castiel's vessel began deteriorating, until he could no longer hold it together. Coming to Sam and Dean for help, he, with the help of Dean and Bobby, opened the door to Purgatory again and hurled the souls back in. Shortly after Castiel had got rid of the souls and his body was repaired, he realized the Leviathans were still inside him. Unable to hold up against them, he finally succumbed and the Leviathans surfaced, telling Dean that Castiel was now "gone". Relishing their new-found freedom, they inform Dean that now they are going to have fun.



However, they are soon forced to leave Castiel's body due to the vessel being unable to handle them. So, using Castiel, they head to a water reservoir and, using the water, spread to the population, taking new vessels, thus possessing multiple people. They then break into two distinct groups; those who can control their hunger and proceed to observe the human world and those who act careless in their feeding and thus draw attention.

Two Leviathans meet in a park to discuss the current situation. The Leviathan possessing Edgar reveals to the Leviathan in the girl's body that he is here because the "Boss" heard about the careless feeding of some of the others and is angry that it has drawn human attention. He tells her to get the Leviathans in the area in line because their leader "hates bad news".

They realize they can't leave Sam, Dean and Bobby alone, and decide to get rid of them. This leads to Edgar burning Bobby's house down and attacking Sam and Dean. Sam and Dean manage to get away and Leviathans set their feelers out. They begin tracking the Winchesters, flagging their credit cards. Chet manages to catch up with Sam and Dean, but is stunned by Don Stark. Sam and Dean put the body in the Impala.

Later, two Leviathans impersonate Sam and Dean and go on a bloody rampage; turning the brothers into public enemies and to draw them out of hiding. Thanks to Bobby discovering the Leviathans' weakness to Borax, they are able to deal with their dopplegangers and again convince the world they are dead. The Leviathan disguised as an FBI agent comes to collect the bodies, but the sheriff lies to them. The Leviathan returns later and eats the Sheriff and his daughter.

Elsewhere Crowley meets with the leader of the Leviathans who is impersonating businessman Dick Roman. Crowley attempts to secure an alliance with the Leviathans but Roman see's through Crowley and tells him he would rather "swim through hot garbage than shake hands with a bottom feeding mutation like you." The creature explains that it sees demons as lesser than humans, whose only use is a food supply. Roman tells Crowley not to bother him again and warns him that, if not currently occupied with other matters, the Leviathans would wipe demonkind out in a heartbeat.

While the brothers work to discover the Leviathans' master plan they learn from the deity Chronus that the Leviathans will soon cover the earth, leading to oblivion.

After a run in with a Leviathan, the brothers are told that Dick is building a research centre to, apparently, cure cancer. "We're only here to help".

At the beginning of "The Girl With The Dungeons and Dragons Tattoo", the ghost of Bobby tells Sam and Dean that he thinks the Leviathans aren't here to hunt humans, but to harvest them as cattle - hence explaining their desire to "cure" humans of diseases. Sam and Dean enlist the help of hacker Charlie Bradbury to infiltrate Dick Roman's headquarters, and they are able to intercept a package which turns out to be a stone tablet.

In the next episode "Reading Is Fundamental", the chosen prophet Kevin deciphers the tablet the Winchesters stole from Dick Roman. The tablet, which holds one of the Words of God, is revealed to be an "emergency note" concerning the Leviathans. It states that the Leviathans can be killed with the "bone of a righteous mortal dipped in the blood of the fallen". Castiel provides some of his blood, as he is a fallen angel.

Also at the end of this episode, Edgar kills the two angels who were assigned to reunite Kevin with his mother.

Known Leviathans

 * Richard "Dick" Roman - The boss Leviathan.
 * Castiel (He initially hosted all the Leviathans, up until they disposed of him, taking on all new forms)
 * Edgar
 * Dr. Gaines/Annie
 * Chet
 * Leviathan!Sam and Leviathan!Dean
 * Agent Valente
 * Agent Morris
 * Susan - Dick's assistant.
 * Joyce Joyce
 * George George - Joyce's assistant.
 * Leviathan!Pete - Charlie's supervisor; formerly under the guise of a human named Tarrell
 * Victor - Leviathan responsible for picking up a package at the airport.

Trivia

 * They are the main antagonists of Season 7.
 * They are probably based upon the biblical sea monster mentioned in Job 41 or the biblical sea monster mention in the first chapter of Genesis as the first inhabitants of the seas.
 * The Leviathans are unusual in the Supernatural universe in that they are the only creatures to possess another creature which is using a vessel, because they possess Castiel while he is in possession of Jimmy Novak.
 * They were referred to as "The Old Ones" by Death. This may be a reference to the ancient creatures described by H.P. Lovecraft, who had previously created a portal to Purgatory, where the Leviathans were once imprisoned.
 * They are the most powerful, dangerous and indestructible antagonists to be faced by the Winchesters up to date.
 * If a Leviathan gets very hungry it feeds on almost anything that comes in its path (including humans, Angels, Demons and various other creatures - even other Leviathans).
 * Leviathans are the only creatures to feed on almost all the other creatures (humans, Angels, Demons) though most of the time they are seen feeding on humans.
 * Crowley, the King of Hell, fears the Leviathans.