Leviathan (Final Fantasy III boss)

Leviathan is a boss in Final Fantasy III. The dungeon in which it resides can be entered by passing over Lake Dohr with the canoe and coming into contact with the large shadow. The party must then traverse a short series of cavern rooms before facing Leviathan. Once the Lord of the Seas is defeated the party can use Leviathan as a summon.

Strategy
Before you enter Leviathan's area, go with the Black Mage or Magus job classes to have a character that can use Thundaga. Leviathan's physical attacks occasionally inflict petrification so at least have a character equipped with an Aegis Shield or a White Mage ready with Stona. Leviathan can also cast Protect and Haste, so using Erase is a must. Watch out for Blizzaga as it can cause 1500 points of damage and be especially wary of its ultimate attack Tsunami which can cause 2000 points of damage to the party. First you should break loose all your strong attacks and use Thundaga; if you're successful, it can cause a total damage of 8000 to Leviathan. After four or five turns, he should fall.