Aka : Rahab

Element/sin : water, connected with the primeval waters of the ocean 

Shape : enormous and invincible armored whale with seven heads 

Rank : Prince of liars, Master of the ocean, reigned also as king of beasts, feared by God and men alike 

Origin : derived from the Canaanite Lotan, and that he is related to the Babylonian Tiamat and the Greek Hydra

Myths :Leviathan, the great sea-serpent, angrily churns the oceans of the Earth, waiting for the day of Judgment when he will devour the souls of the damned.At the time of the resurrection, Gabriel will fight against Leviathan and overcome.

Association :  Behemoth, Satan 

Source: Book of Jonah, Book of Enoch

Quote :

 'And that day will two monsters be parted, one monster, a female named Leviathan in order to dwell in the abyss of the ocean over the fountains of water; and (the other), a male called Behemoth which holds his chest in an invisible desert whose name is Dundayin, east of the garden of Eden.'

1 Enoch 60:7-8

 'His back is made of rows of shields,
Shut up closely as with a seal...
His sneezings flash forth light,
And his eyes are like the eyelids of the dawn.
Out of the mouth go flaming torches;
Sparks of fire leap forth...
In his neck abides strength,
And terror dances before him.

Book of Job

 "In that day the Lord will punish,
With His great, cruel, mighty sword
Leviathan the Elusive Serpent--
Leviathan the Twisting Serpent;
He will slay the Dragon of the sea.

 Isaiah 27:1