I know that the GF's topic has been really worn out, but I feel the need to try it myself:
Odin (because he appears randomly)
Bahamut (he lives in the research center in the ocean)
Diabolo (I know it's a strech, but it's spanish for the Devil)
Carbuncle??
maybe I need to think about it more...

It's probably not doing me much good to guess, seeing as BG isn't online