You won't be able to abuse this indefinitely, but you will be able to get 4 Leftovers and 2 Snorlaxes out of it. If it works like Dialga and Palkia, they only reappear once if you beat the Elite Four. You can steal and kill them, then regenerate them and catch them.Ingame question here: according to Serebii the two Snorlaxes in Heart Gold and Soul Silver will reappear if defeated once you have beaten the elite four again. Can this be done multiple times? If so then you can steal the leftovers they may be holding with theif, defeat them, and then come back later and do it again! That would be great (although I already have 6 leftovers in platinum so I could just trade them.)