Liverless boars and other Azerothian freaks of nature
People have long noted that quests to gather animal parts usually have illogically low drop rates. There are enough hoofless zhevras, talonless harpies, eyeless buzzards, and brainless basilisks running around Azeroth to confuse a whole university of evolutionary biologists. ("Hey, maybe they knew adventurers were killing them for their horns, so they evolved illusionary horns! Huh? Huh?") Strangely, bosses always have their organs, but only if you're on a quest for them. Maybe that's how they got to be bosses, because they weren't randomly missing their hearts and ears and such.
The lore's explanation for this is that when you're fighting the beasts and demons, a lot of their organs get squished into an unusable state. So if you don't find a horn on that satyr, you chopped it in half with your sword, and if you don't find a brain in that ogre, you used Mind Flay one too many times. This works for most things, but one of the Hellfire Peninsula quests really tests this idea.
You're supposed to return orc blood to an apothecary. A warrior guildmate of mine got extremely frustrated by the low drop rate, and asked, "I'm hitting these orcs with an axe. Shouldn't there be blood all over?" Try as we might, we couldn't think of an explanation for it. A mage might have fried up all the blood with a fireball, and maybe a warlock or hunter's pet could have drank the blood before the character got to it (ew), but a warrior can't really do anything to keep blood from being unusable.
Can you think of a reason why the blood might not have been there? Have you run into anything as confusing as this while looking for various body parts?
