The word "Leviathan" is used in the bible five times. In Job 41:1; Psalm. 74:14; 104:26; and twice in Isa. 27:1. There are other verses which reference Leviathan without naming it. Let us first look at Chapter 41 of Job where a description of the "Leviathan" is given to Job by God. Let us see what we can find out about him. Some have called him a crocodile, but as we will see from the following description that those who call him a crocodile have never read Job chapter 41. From the following verses of Job chapter 41 we find that:
1 You can't catch him with a fish hook or tie him up.
3 He will not beg you for mercy.
4 He will never serve you or do as you command.
5 You can't put him on a leash to make a pet out of him for your children.
6 You can never make a meal out of him.
7 You can't stick a harpoon into him.
8 If you tangle with him once and live through it you will never go near him again.
9 Even the sight of him is enough to make you try to hide.
10 He is so terrible that no one would dare attract his attention.
12 He is Very powerful, and well proportioned.
13 You can't skin him, and he has two heads.
14 You can't open or close his mouth, even the sight of his teeth will put terror into you.
15 - 17 He has scales that are beautiful and fitted so close together that air can't get between them, much less anything else. You can't separate his scales by any means.
18 When he sneezes a light shines out. His eyes glow like the morning sun.
19 When he opens his mouth fire comes out.
20 Smoke pours out of the nostrils of his nose like steam rising out of a boiling pot.
21 His breath alone is so hot that it will start fires and flames shoot out of it's mouth.
22 His neck is very strong and Nothing is painful or hard for him.
23 His flesh, or muscles, are so firm that they are hard to the touch and you can't push even a dent in them.
24 His heart is as hard as a lower mill stone that makes flour.
25 The very sight of him strikes fear into the hearts of the most mighty and brave men. They call on God to help them because they believe that they will be killed.
26 He can't be harmed (cut) by swords, spears (light for throwing), arrows, or lances (a heavy spear for thrusting, not throwing).
27 Hitting him with iron or brass is like hitting him with grass or rotten wood.
28 He laughs at arrows and stones from a slingshot.
29 He scorns light spears. You can't threaten him.
30 His bottom side is rough and sharp like broken pottery.
31 He stirs up the sea to make it look like its boiling.
32 As he travels through the sea he leaves a churned up trail in the water that makes it look like frost.
33 There is absolutely nothing on this earth like him. He is absolutely fearless since nothing on the earth can harm him.
34 He is the king and ruler over everything on the earth.
Well there it is. What kind of a creature or animal do you think it is from that description?
It sure doesn't sound like the crocodile that we have today. The crocodile we have today we make shoes, suitcases and belts out of, and men do eat him. There are no scales on a crocodile.
What is being described here is a two headed creature that breathes out fire. A creature that knows that it is the most beautiful ever created. A creature that is indestructible from everything and everyone except God. A creature who, the very sight of, causes terror in the hearts and minds of men.
It was Known to Job
A one of a kind creature that was alive and known to Job, who was a real person (see Ezekiel. 14:14, 20; James 5:10-11) and who is believed to have lived around the time of Abraham.(Abraham was born around 2166 BC). We know that Job knew this creature from the way that God started the description of Leviathan. We can see in the first couple of verses an assumption of Job knowing the creature by the hearing it's name. Only with God, its not an assumption, it is knowledge.
It was Known to Asaph
Asaph wrote psalm 74 which speaks of the heads of leviathan in verse 14. This confirms the two heads of leviathan. Asaph lived in the time of David and Solomon. This puts the time of writing between 1040 - 940 BC.
It was Known to an unknown author
Psalm 104, written by an unknown writer, in verses 25 - 26, shows leviathan to be a sea creature.
It was Known to Isaiah
Isaiah knew of leviathan and referred to him in Isaiah 27:1 where reference is made to God punishing leviathan by killing him. And when will this happen? Verse 26:21 and 27:1 says it will happen on the day when the Lord comes out to punish the inhabitants of the earth for their iniquity. That Day of the Lord is yet in the future. That means that Leviathan is alive and well today.
Isaiah also identifies him in Isaiah 27:1 as a "piercing serpent", a "crooked serpent" and a "dragon".
Compare Isaiah 27:1 with Revelation 20:2 where God's angel binds the "dragon" and the "old serpent" who is also identified as the "Devil" and "Satan" and with Revelation 20:10 - 11 where Satan is destroyed on the day of the Great White throne judgment where the sinners will be judged.
Isaiah also refers to a "fiery flying serpent" in Isaiah 30:6 which seems to be referring to Satan.
In Job 41:15 a statement: His scales are his pride -- perhaps this can be explained with the following passages from Ezekiel. 28:12 - 19, where a description of Satan is given. Ezekiel 28:13 describes Satan's covering, see how many other verses here fits in with the description of Leviathan as given in Job 41.
12 Son of man, take up a lamentation upon the king of Tyrus, and say unto him, Thus saith the Lord GOD; Thou sealest up the sum, full of wisdom, and perfect in beauty.
13 Thou hast been in Eden the garden of God; every precious stone [was] thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
17 Thine heart was lifted up because of thy beauty, thou hast corrupted thy wisdom by reason of thy brightness: I will cast thee to the ground, I will lay thee before kings, that they may behold thee.
14 Thou [art] the anointed cherub that covereth; and I have set thee [so]: thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire.
18 Thou hast defiled thy sanctuaries by the multitude of thine iniquities, by the iniquity of thy traffick; therefore will I bring forth a fire from the midst of thee, it shall devour thee, and I will bring thee to ashes upon the earth in the sight of all them that behold thee.
This compares with Job 41:18 - 21.
19 All they that know thee among the people shall be astonished at thee: thou shalt be a terror, and never [shalt] thou [be] any more.
This fits with the description given in Job. 41:25
15 Thou [wast] perfect in thy ways from the day that thou wast created, till iniquity was found in thee.
16 By the multitude of thy merchandise they have filled the midst of thee with violence, and thou hast sinned: therefore I will cast thee as profane out of the mountain of God: and I will destroy thee, O covering cherub, from the midst of the stones of fire.
This fits Job 41:10, 25; Isaiah 27:1; and Revelation 20:10 - 11
The answer then appears to be that Leviathan is a Sea Serpent, a Fire Breathing Dragon, and also Satan.
Throughout the bible, there are 4 names used for Satan. The names and meanings are:
1. Dragon = cruelty
2. Old Serpent = cunning treachery
3. Devil = deceiver
4. Satan = adversary
May God help you to understand His word.