Ok, since nintendo never really gave an official explanation as to why the goombas in Mario World were different from all the others, I came up with my own little idea ^_^. Anyway, I always figured that goombas were either created magically by Bowser (or the magikoopas I suppose). And if you look at the goombas in Mario World you will notice that they are shaped kind of like the berries that Yoshi eats, where as usually they look like mushrooms. So I figured since the Mushroom Kingdom is full of...well mushrooms, Bowser uses them to make a seemingly infinite supply of minions, but since the little berries are most abundant on the Dinosaur Islands, then he made goombas out of them instead. Feel free to shoot down this theory. lol.
