How to Get a Gold Chocobo in Kalm

Play through the game until the point when you have full control of the Highwind and the Ruby and Emerald Weapons are released into the world. Ruby Weapon resides in the Corel Desert, which surrounds the Gold Saucer. Fly to the desert and you will see a red tentacle sticking out of the ground. Fly into it to initiate the battle.

Defeat Ruby Weapon. This is one of the most difficult boss battles -- considered by most players to be considerably more difficult than the final battle with Sephiroth -- in the game. There is no definitive way to defeat Ruby weapon since many players have used different strategies to great success. Avoid equipping elemental materia in your weapon slots, but place Fire-elemental materia in your armor slots. Master-level Fire materia will allow you to absorb Ruby Weapon's fire attacks.

Use one of your characters to attack -- Cloud should be your strongest character and is best suited to this task -- and use the other two, whoever has the most HP and best defense stats, as support characters. Bring as many Mega Elixirs and Dazers as you can. Dazers are surprisingly effective at stunning Ruby Weapon for a few turns at a time.

Use physical attacks and your strongest non-elemental summons, such as Odin and Knights of the Round, to bring Ruby Weapon's HP down. If you have Master-level Mime materia on all three characters, you can perform an endless cycle of summons and prevent Ruby Weapon from attacking. Otherwise, keep the party's HP up and keep Ruby Weapon stunned with Dazers or Stop spells as Cloud attacks. Use magic like Haste and items like Hero Drink to boost everyone's stats until Ruby Weapon is defeated.

Collect the Desert Rose item from Ruby Weapon at the end of the battle. Use the Highwind to fly to Kalm, the village adjacent to Midgar's outskirts. Land outside of the village and walk the rest of the way. Go to the northeast corner of the village and enter the building here. Head up the stairs and speak with the old man. He notices that you have the Desert Rose and offers his Gold Chocobo as a trade for it. Accept his offer to receive the Gold Chocobo.