Leviathans

''"They're pretty much like shapeshifters, really, but more into eatin' folk then just killin' them." - Bobby Singer''

Leviathans were God's first beasts, and thus pre-date angels, humans, and the soul itself. Being too much to control, God created Purgatory and locked them therein.

Eve may be a Leviathan due to her homeworld being Purgatory and her ability to shapeshift into whatever she wants. Also due to her ability to bite people and turn them into monsters this heightens the possibility that she is a Leviathan.

Nature
''"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 first, creations. Unfortunately the beasts proved to be too powerful and destructive and God was concerned they would destroy everything around them so he sealed them away in Purgatory. Death describes them as "clever and poisonous".

In spite of their chaotic nature, it is established that the Leviathans have a strict hierarchy, with several of them taking orders from a yet unknown leader. These individuals in turn have authority over other Leviathans. The leader orders 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 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.

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 of those who can control their hunger and proceed to observe the human world and those who act careless in their feeding; drawing 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 them burning Bobby's house and the Leviathan possessing Edgar attacks Sam and Dean. Sam and Dean managed to get away, and Leviathan set their feelers out. They begin tracking the Winchesters, flagging their credit cards.

One Leviathan 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 pulic enemies and to draw them out of hiding. Thanks to Booby discovering the Leviathans weakness to Borax they are able to deal with their dopplegangers and again convince the world they are dead.

Elsewhere Crowley meets with the leader of the Leviathans who is impersonating buisnessman 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 ocupied with other matters, the Leviathans would wipe demonkind out in a heartbeat.

Powers & Abilities

 * Immortality - Death reveals that the Leviathans were God's first creations, being before angels, humans, and souls.
 * Shapeshifting - Upon physical contact, they can transform into the person they are in contact with. They can also use hair instead of physical contact to assume a person's identity. Soon after changing, they eat the original person. They are also able to take on the memories of not only those they possess, but those they shapeshift into.
 * Regeneration - Leviathans can heal from injury quickly.
 * Impervious to silver- Leviathans remain unaffected by silver. 
 * Superhuman strength - The Leviathan's have proven to be extremely stronger then humans as they can over power them while feeding on their flesh.
 * Invulnerability - So far, it hasn't been revealed what can kill a Leviathan. However they can be weakened with Borax.
 * Possession - They can take over any one by a touch.

Weaknesses

 * Witchcraft - It's unknown if witchcraft can kill them, but they are affected by it. This is seen when Don Stark stuns one in a motel room.
 * Decapitation - A Leviathan can be beheaded, but it's not permenant since the head eventually re-attaches itself back to the body. If the head is kept a considerable distance from the body, it appears they are not capable of re-attaching the head to their body.
 * Borax - Acts as an corrosive acid. When a Leviathan comes into contact with this chemical it causes severe pain and melts away flesh. It is unclear if they can heal once contact is made with this chemical. Splashing Leviathans with borax makes it possible to get close enough to behead them.

Trivia

 * They are the main antagonists of Season 7.
 * They are possibly 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 in the 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.

Season 7

 * Meet The New Boss
 * Hello, Cruel World
 * The Girl Next Door
 * Shut Up, Dr. Phil
 * Slash Fiction