Final Fantasy III PSP - Giant Rat

So, your first real boss where you can actually use the Job System. Well, at least in the 3D version of FF3. During this time, your characters are turned small, because you couldn't enter this dungeon otherwise, so any physical damage will be pretty pathetic. Luckily, you can always have access to Black, White and Red Mages and pound him with spells. Sadly, my Luneth didn't survived this fight.