Well, FFI has no summons, but it does have the four elementals, Tiamat (wind), Lich (earth), Marilis (Fire), and Kraken (Water); Lich would probably be the easiest because just about any robed undead would work. Marilis would be the hardest, seeing as I doubt anyone's made a four armed snake woman...meanwhile Tiamat is just a recolored Bahamut, but I assume that Bahamut ZERO wouldn't look anything like the proper unit - is that already done, because admittedly, Bahamut would be a better unit, as it's a lot more recognizable...as for Kraken, no one cares about Kraken, as it was replaced by Leviathan...
Can't help you on FFII...sorry...
FFIII should probably have Sylph, an aggregation of three little green faries. Sylph is, after all, the most recognizable summon that was later removed, and I think FFIII was it's first appearance...
EDIT: Later looked it up and realized that was the wrong Final Fantasy. I'm gonna go with Titan, this time...
Personally, I think that Carbuncle would be pretty awesome for an FFXI summon...but instead of normal Carbuncle, perhaps a mutant giant Carbuncle?
Can't help you on FFII...sorry...
FFIII should probably have Sylph, an aggregation of three little green faries. Sylph is, after all, the most recognizable summon that was later removed, and I think FFIII was it's first appearance...
EDIT: Later looked it up and realized that was the wrong Final Fantasy. I'm gonna go with Titan, this time...
Personally, I think that Carbuncle would be pretty awesome for an FFXI summon...but instead of normal Carbuncle, perhaps a mutant giant Carbuncle?