I was transferring a few of my pokemon over from Leaf green to my copy of heart gold. I brought over a few pokemon, but most importantly for this, my Charizard. I searched around and found the first five pretty easily, but took a long time finding Charizard. After running through every patch of grass, I gave up and used surf to check the water, and sure enough he was there in the water. Since he was a fire type, I wasn't expecting him to be there. So is a pokemon limited to certain locations by its type? or is it because Charizard can fly over the water? Could there be something weird going on with my game?