Although they are more inclined to run than to stay and fight, chocobos can fend for themselves when pushed; chocobos can heal themselves and cast supportive magic, and attack with Choco Kick, which does a moderate amount of damage to a single target. From Chapter 3 onwards they can use Choco Meteor, which does a major damage to all opponents.
Completed the Mi'ihen Highroad mission in Chapter 2, returned, talked to Clasko and Calli, and let them on the Celsius.
The player must go to the Calm Lands and defeat the monsters in the ex-Monster Arena. Clasko will give some greens to go out and catch chocobos with.
The prospective owner must encounter a chocobo in battle; first enticing it to stay by offering it Gysahl Greens; extended battles may require a steady supply of the greens as the party clears away the accompanying fiends. When all the fiends have been defeated one more Gysahl Green will ensure capture. During the battle the chocobo may attack; it is important the catcher does not retaliate or the chocobo will almost certainly run away. First Strike will guarantee the party has an opportunity to use Greens before the more chocobo can run away.