From the Journey Pig Statue at Shangri La, go right and up the hill, then take the path left. On the rocks in the background, the tortoise should be climbing up and down one of them. (It may be hard to see the tortoise itself, but you should be able to catch sight of the sparkles it gives off.)
The tortoise itself has only 300 HP and gives off a grand total of 1 EXP, but it is real use lies in it is other yields. It gives you 8888 Dagols, which is useful in itself, but the true prize is the VIP Badge it carries. Each VIP Badge that you equip reduces the prize of store items by 20%, for a max of 40% off. However, it only has a 5% chance of dropping it; couple that with it is regeneration rate, and it's obviously very ineffective to try and get it this way.
As such, you want to bring in three characters capable of thieving, or, if you can, equip a Beckoning Cat in one or both of your slots. The main problem here lies for those choosing the Fairy Path; they generally cannot get the best thieves, and those they can get are not easy to recruit. Nevertheless, you will almost HAVE TO suck it up and get Nocturne if possible, because your chances increase practically tenfold with him on the team.
The prospects are as such: if on the Human Path, Ortoroz, Sonata, and Flau, of which the latter two are better options, as they have less attacks and can get more chances of stealing in. If you're before the split, Nocturne, Herz, and Alba are your best bets. If on the Fairy Path, bring in Ben and ONLY Ben, and heal the Dagol Tortoise multiple times as it falls near death,
until you believe you have obtained the Badge.
Just a note: Even if you do obtain the Badge, it will not appear on the list of spoils that you obtain after battle, and will instead just show up directly in your inventory.
(thanks to ©2006-2008 Darkstar Ripclaw http://www.gamefaqs.com/features/recognition/56748.html?type=1 http://www.supercheats.com/playstation2/walkthroughs/radiatastories-walkthrough09.txt)