Chocobo’s are fun loving creatures that are often kept as pets, and used for transportation. After acquiring the highwind, you can raise your own Chocobo at Choco Bills Chocobo ranch near the mythril mines. Raising Chocobo’s isn’t cheap. You’ll have to buy Chocobo stables from Choco Bill at 10,000 Gil and piece, and you’ll end up spending a small fortune on Greens and Nuts. It’s also quite time consuming due to the time and cost it takes to train and breed Chocobo’s.
It’s not necessary to breed Chocobo to win the game, but it’s an excellent
Side-quest, (probably, the best side quest out of all the Final Fantasy games,) plus each special type of Chocobo (Green, Blue, Black, and Gold) gives you access to a new cave with special Materia, including the ultimate Summon Materia. Green, Black, and Gold Chocobo’s also enable you to reach the Forest of the Ancients (near Cosmo Canyon) without defeating the Ultima Weapon.