This article is from the Final-Fantasy and other Square Soft Games FAQ, by firstname.lastname@example.org (Nick Zitzmann) with numerous contributions by others.
Here are some brief instructions. Remember, there is a random element to
Chocobo breeding, so it may take a couple of tries to get the kind of
Chocobo you desire. Also, be sure to save after correctly completing a
step as you'll undoubtedly have to reset a couple of times during the
* After getting the Highwind in Disc 2, return to the Chocobo Barn.
You can purchase stalls from Choco Bill for 10000 gil per stall,
and you'll need at least four stalls (you can purchase six total).
Remember, after you don't need chocobos any more, you should just
kick them out to make room.
* Before you can start breeding, though, you need to stock up on
supplies. Fly to either Bone Village or the Chocobo Sage's
house. If you run around on the grass, you'll eventually fight
an enemy called Brachioladus. Fight that enemy three times,
stealing a Carob Nut from it each time (you'll need the Steal
materia first). Then, go to the Goblin Island or Round Island
and steal a Zeio Nut from the Goblins that live there. Finally,
go to the Chocobo Sage's house and purchase 40 Sylkis greens
* Equip a Chocobo Lure materia. Fly to the chocobo tracks near
the Gold Saucer (by the shore), and capture a chocobo. Press
X to dismount from the chocobo, and choose the option to return
it to the Chocobo Barn. You need to capture 2 chocobos from
here, although you can get the other chocobo later or not get it
at all, if you wish.
* Now, fly to the chocobo tracks near Mideel. Capture a chocobo
here, and send it back to the Chocobo Barn. Once again, you can
capture a second chocobo here, but you don't have to.
IMPORTANT NOTE: The gender of a Chocobo is not determined until you
return to the Chocobo Barn and name them. Therefore, it is advised
that you save your game before naming them. That way, if you don't
get the kinds you want (see below), then you can reset and try naming
them again and seeing if their gender changed.
* Return to the Chocobo Barn and talk to Choco Billy. Name your
Chocobos (this will put them in the stalls). Now, go up to
your chocobos and examine them by pressing O. You'll want to
make sure that you have one male and one female (or two males
and females, if you caught four chocobos). Furthermore, one
of them should be the running kind (usually you'll want the
females), and the other should be the walking kind (usually,
this should be the males).
* So, you have at least one male and female, and one is a walker
and the other is a runner, right? If not, you'll have to
release the chocobos that aren't the ones you want and go and
capture more (or reset, if you heeded the important note).
* Choose to mate the chocobos, and tell Choco Billy that you
want to feed them a Carob Nut as well. Hopefully, you'll
get a colored chocobo the next day! It should be green or
blue. If not, you'll have to reset and give it another go.
Keep note of your baby chocobo's gender--it's very crucial
IMPORTANT NOTE 2: Later on in this process, it's required that
you race chocobos at the Gold Saucer (see below). However, if
you have trouble getting the correct type of chocobo during
these few steps, you can optionally choose to race them. The
better your chocobo's race class is, the higher chance you have
of getting the needed color type of chocobo.
* At this point, you have three options. You can repeat the last
few steps (get a chocobo from the Gold Saucer, get a chocobo from
Mideel, make sure they're both the correct types, and breed them
using a Carob Nut). Or, if you got two other chocobos the first
time around, you can then breed them together. Your third choice
is to use the same pair of chocobos that you just breeded. In
that case, you'll have to waste some game time, as chocobos that
have just mated can't do it immediately again.
* In any case, you'll want to breed your chocobos together and get
a blue chocobo, using the steps outlined above. Your blue chocobo
MUST be the opposite gender of your green chocobo, or you can't
mate them. Feed the blue chick and the green chick 10 Sylkis
* Get in the Highwind and go to the Gold Saucer via North Corel's
ropeway. Go to the Chocobo Square and talk to Ester. Tell her
that you want to race using either your green or blue chocobo.
The goal here is to keep racing until your chocobo's race level
reaches A. To do this, win the races consistently; it will take
a couple of tries. To insure winning, just use Automatic Mode
for most of the race and hold R1 + R2 to recover lost Stamina
while racing. After one chocobo has hit rank A, do the whole
racing process again with the other one.
* Once your green and blue chocobos are both rank A, return to the
Chocobo Barn. Breed the two chocobos together, using your last
Carob Nut (refer to the above steps for help). If everything
worked out, you'll have a black chocobo.
* Fly to the Northern Continent (the snowy one), and look for
Chocobo tracks on the western edge of the continent. Land and
then capture a chocobo at the tracks. Return to the Chocobo
Barn and name it (it should be the opposite gender of your
black chocobo, and should be the 'dashing' kind--it runs very
fast with it's head down).
* Now for the fun part. Feed 10 Sylkis Greens to the black chocobo
and the dashing yellow chocobo. Then, go _back_ to the Gold
Saucer and race both Chocobos up to race class A again! When
they're both at rank A, go back to the Chocobo Barn and tell
Choco Billy that you want to mate them, using the Zeio Nut this
time around. With a little luck, you'll get the Gold Chocobo!
What's the point of doing all this? Well, Green Chocobos can cross
mountains, Blue Chocobos can walk along rivers and shallow areas of the
sea, and Black Chocobos can do both, and they can also go up and down
waterfalls, or over any cliff or drop (like the Glacier up north or the
canyon surrounding the Forgotten Capital), unlike the other two types of
colored chocobos. The Gold Chocobo can do everything a Black Chocobo can
do, and it can also cross the deep sea areas as well.
Unlike wild chocobos that you can catch, the ones that you've named are
tamer, and if you get off them, they will stay where you left them until
you get back on. You can also ride a tame chocobo into the Highwind and
transport them around with you on the airship.