Actually, Chocobos didn't appear in the Final Fantasy series until either FF2j or FF3j (I have my bets on FF2j, but...I could be wrong) Chocobos were not in the first Final Fantasy. There were, however, mad ponys that were ridiculesly powerful and wiped me out the first few times I tried to leave teh city.
And I'll have you know that we also say "Kweh" in the "CuteChocobo" series-(Chocobo's mysterious Dungeon, Chocobo's Mysterious Dungeon 2, Chocobo Racing, and Dice de Chocobo).
I think of "Kweh" As sort of a cute sound/sound of a youthfull chocobo, but of course that has no real factual background. Whark or Kweh, what ever.
And to the person that said Chocobos are a copy of those birds in joust...
The Chocobos in Black have all ready been informed of your address...They uhh...Just want to talk to you...Yeah.
Kweeh! Forget Whark! Kweeh! Is better!