I think SSGoku meant his HP. The easiest way to level up is against the Grand Dragon, but here's the trick. Equip all your party members with Auto-Reflect. This way, when the Grand Dragon casts Thundaga, it reflects back on him, doing somewhere in the vicinity of 5000 - 8000 HP damage. Also, make sure Quina is in your party and has Level 5 Death ability. Equip Quina with Auto Haste as well as Auto reflect. One hit with Level 5 Death does it every time! You need Quina in your party equipped with Millionaire in order to receive $5000 from Gimme Cats (otherwise it's only $2500). The best place to fight the Grand Dragon is either above Giamaluke's Grotto on the grass, (for only Grand Dragons), or the long skinny island with a singe forrest two islands above Daguerro, (for Gimme Cats + Grand Dragons). I suggest the Gimme Cat way as the amount of money you earn is way worth it. If you need to aquire Level 5 Death, go to the Iifa tree's lower entrance and fight a Stroper. Have Quina eat it.