Nepto Dragon

Nepto Dragon is a boss in Final Fantasy III. He guards the Bay of Nepto, and thus the party cannot sail the seas of the Floating Continent until his rage is appeased. After the statue of the Nepto Dragon in the Nepto Temple is restored by retrieving the Nepto Eye from the Giant Rat, Nepto will cease to appear and the party is free to pilot their ship to Castle Argus.

Strategy
Nepto Dragon's battle is like Bahamut's, so your only chance of getting out of this battle is running from it, if you can run away from it. In the NES version though, you can defeat him by using the Fully Equipped Onion Knight strategy ("FEOKS"), yet defeating him does not defeat the dragon at all, and it will be faced again if the player tries to leave the bay of Nepto.