This example isn't too bad compared to most, though, since Joy Pendants are very easy to get and you'll likely have far more than enough before you need to make the trade.
To illustrate, one villager sends you on quests to kill a certain number of creatures, culminating in her sending you to kill an optional boss in a location you might never reach. Unfortunately, it turned simple fetch quests into a bundle of Twenty Bear Asses. Castlevania: Order of Ecclesia took the NPC sidequest ingredient from its predecessor, Portrait of Ruin.ANNO: Mutationem: At Freeway 42, to repair the broken lift and rescue a merchant trapped on it, Ann must multiple collect machine parts from the nearby enemies and take to the lift's control panel to reactivate it.The opposite can also happen where the player may receive multiple random drops from a single creature, if it makes logical sense for the creature to carry more than one of the item. How you kill the bear rarely affects the odds of its ass being dropped, either, so psychic or spiritual attacks are no more likely to get an intact drop than attacks that reduce the target to Ludicrous Gibs or burn it to a crisp. However in some cases only pristine bear asses will do, even when the woodsman just wants proof you killed twenty bears. This can make sense if the part needs to be intact for its purpose (like making armor from an animal pelt), and the body part may have been ruined during the fight.
This sort of quest can draw attention to the inherent Fridge Logic of Random Drops, such as when the drop in question is a vital body part that all monster corpses should have, like a liver, feet, skin, or a head. The common hypothetical example involves a woodsman NPC asking the Player Character to deliver 20 sections of bear to him. A type of Fetch Quest that involves going around killing enemies and collecting a certain amount of a specific item that these enemies randomly drop.