^ Good idea on the post above mine.
Though, i think this sounds a lot like Pokemon Mystery Dungeon which had pokemon-specified items, and eh, i dont know. Would i like to have a part that's taken from each existing creatu?
Though, if they were to be items that they might lose without pain, such as feathers or fallen teeth, i'd support. But Ahea fin? Have you really ripped it out of a living ahea or taken it from a dead corpse? om nom nom. :s
Kind of interesting idea, but hard to make it.. not appropiate, but.. animal-friendly.