Leviathan (Supernatural)

"Why do you think he created Purgatory in the first place? To keep those clever poisones things out"- Death explaing the Leviathan

Leviathans are the main villains encountered in the Seventh season of Supernatural.

Appearance and Anatomy
The true form of a Leviathan has not be seen so far far in the show but a glimpse of them under the water shows a serpent like shape.

To blend in on Earth Leviathans take human vessels. These vessels appear compleatly normal but bleed a black oily substance when injured.

When a Leviathan is attacking or feeding they dislocate the jaw of vessel to monstrous proportions to reveal a mouth full of sharp teeth and a twin forked tongue.

Diet
Leviathans have an immense near inquenchable appitite for human flesh. It is implied they need to eat daily to survive and function properly on daily basis, more experience and elder Leviathans can control the hunger while younger Leviathans act rash in their killings. Each Leviathan may be different, as one may enjoy a preference on their meal by adding ingredients such as cheese or garlic to their food while some other will rather try to evoke emotional responses in their victims to flavour the meat.

Abbilities

 * Shape shifting: After taking a vessel a Leviathan is capable of shapeshifting into another person provided they have a sample of DNA. This can be acquired through physical contact or a strand of hair.
 * Super Strength: Leviathans are stronger than normal humans.
 * Possession: Leviathans can take over human bodies
 * Regeneration: Leviathans have a frigteningly efficient regeneration. Severed limbs and their heads are capable of reataching themselves after separation.

Weaknesses

 * Borax: It is discovered that Borax is the only known substance capable of harming a Leviathan. Ecposure to the chemical burns severely in the same a human exposed to powerful acid would react.
 * Decapitation: While the head of a Leviathan can ratach separating the head and taking far enough away from the body appeares to be the only way to put a leviathan down.
 * Magic: Certain spell can temporarily paralyse them.

History
In the beginng the Leviathans came into existace as God's first attempt at creating life. Unfortunately the creatures proved to powerful and destructive and God eventually selaed them into Pugatory to protect the world from their power and hunger.