What creatures would we have to defile by mating them together in order to produce a irl chocobo? I'm being serious here, it's not impossible. A real-life Tigon has already been produce from interspecies breeding. Why not a chocobo? Obviously, an ostrich has to be involved. It is the largest living bird species on earth. Various species of parrot and cockatoo could be used to provide the colored plumage (and, who knows, maybe some of their flight genes will transfer as well). About the only differences between an ostrich and a chocobo anyway are its long snakish neck and its considerably shorter wingspan. Then again, maybe just mate the os with the nearly as large emu.