Best hp:exp ratios in the game?

although not exactly by this order, it looks like the weakest monsters have the best hp\exp ratio. green snails have 8 hp and give 3 exp. thats more than 1\3 of their hp. take himes, for example. they have, what, around 30k hp (at least, im 2 lazy to check now) and give only like 3k exp. thats 1\10.