On your long journey through the world of Final Fantasy IX, you will almost certainly encounter some good, friendly monsters. These are known as land spirits, and each of them will make a request from you. If you agree to their request, you will be able to use the “Attack” command when you are fighting the troublesome Ozma, who’s unlocked in the Chocobo Garden when you inspect the large rock on the upper right hand corner.

You will obtain Garnet’s / Dagger’s strongest Summon, Ark, from defeating Ozma but it is a very hard battle, so be sure you find all the land spirits:

Locations / Their ‘Bribe':

Squirrel: Around Dali. Ore stone.
Ghost: In front of Treno (but not too far) or around the South Gate. Ore stone.
Ladybug: Around the Black Mage Village. Two Ore stones.
Yeti: Forest outside Madain Sari. Two Ore Stones.
Nymph: Forest near Iifa. Three Ore Stones.
Jabberwock: Forest East of Oeivell. Emerald. Feather Suckle: Ice Continent, on the Chocobo tracks. Moonstone.
Galda: Forest outside Gizamaluke Cave after climbing rope. Lapis Lazly.
Yan: Bile Island (small island near center of map). It will keep running away until you have found all eight other Land Spirits. Diamond.