Catch and name a chocobo in the Chocobo Forest. Use Gysahl
greens in battle to summon him! You can also move him to the
Chocobo World mini-game (if you are playing on a Playstation,
you will need a pocketstation, or if not just forget it).
In the mini-game, getting the Mog's Armlet gives your GF the
Mini-Mog ability. When used in battle Mog will partially restore
the HP of all junctioned GFs. When he reaches level 50 he
will evolve and become more powerful in his attack. Same thing
at level 100.