Follow Your Nose Achievement in Final Fantasy IX

Your chocobo's beak will level up based on how many items it has dug up. I would suggest doing the "Diggin' It" achievement first which will likely get you this achievement along the way, then you can grind the rest out with the method below if needed.

Use Chocobo's Air Garden to get the rest of your levels. Play the game here with the High Speed Mode boost turned on. Your movement will again speed up, but not the clock of the mini-game. This should allow you to always get the maximum items and bonuses from left over time. You can grind the remaining levels fairly quickly. Again, see "Diggin' It" for more info on the digging mini-games.