The interior of Leviathan appears as the inside of any sea monster would: the party travels along his digestive system, bypassing rows of teeth and pools of yellow acid that deplete HP. The enemies are mostly aquatic and are weak to Lightning, though the Bolt Fish absorbs this element.
Firion and his allies are swallowed by the creature as they approach the tower. Inside, they are separated from Leila, but find Ricard, who had been missing from Deist. With Ricard's help, they make their way back up to Leviathan's mouth, where they find their ship, but a Roundworm attacks them. They defeat the Roundworm and board their ship once more. When Leviathan opens its mouth, the ship sails out and continues toward the tower.
|Twist Headband||First Floor|
|Power Vest||First Floor|
|Power Armlet||Second Floor|
|Gaia Blade||Third Floor|
|Diamond Shield||Third Floor, guarded by Red Souls|
- [37.5%] Bolt Fish x2-5
- [37.5%] Bolt Fish x1-2, Manta Ray x0-1, Sea Dragon x0-2
- [18.8%] Sea Dragon x1-4
- [6.2%] Manta Ray x1-5
- Red Soul x2-5 (Monster-in-a-box)
- Roundworm (Boss)
The background music that plays inside Leviathan is called "Dungeon".
Leviathan (Biblical Hebrew לִוְיָתָן or לווייתן Liwyāthān) is a violent sea creature referred to in the Hebrew Bible as well as the Talmud and some other ancient Jewish texts. During the golden age of seafaring, the term Leviathan became synonymous with any large sea creature, sometimes describing whales. Bible scholars interpreted Leviathan to be either a demonic sea creature and an enemy of God.
The Talmud and other ancient Jewish sources refer to Leviathan more specifically as a sea serpent, sometimes with multiple heads capable of breathing fire, that was made on the fifth day of Creation. It is said that during the end of days, God will make tents, or sukkah, out of the skin of Leviathan for the righteous to live in. Some have speculated that Leviathan was based on a real animal, the most popular theory being the Kronosaurus and the Nile crocodile.
In the Final Fantasy series, Leviathan is sometimes referred to as the King of the Seas. Its incarnation in the series appears to derive from the legends of the Shinto god Ryūjin or Owatatsumi, said to be the dragon god that reigns over the seas. It also resembles the Chinese dragon, mystical beings seen as the rulers of moving bodies of water, and the Dragon God as the dispenser of rain.