* AluminumChristmasTrees: Cows being fed other cows that causes a disease really has happened. The show even calls it "Mad Cow", in referenced to mad cow disease. This happens when a cow is being fed a meat-and-bone meal mixed with their grain, often from remains of other cows. There is still 4 cases every year of mad cow disease. 14,562 cases happened in 1995, mainly in the United Kingdom. However, instead of turning into zombies (or munchers), it affects the brain causing loss of brain function and mobility. It can take months before showing signs and most people die within the first year.
* CatharsisFactor:
** Marge shooting a muncher Helen Lovejoy with a shotgun in "Don't Have a Cow, Mankind" can be extremely satisfying given how much of an unlikeable [[GossipyHens Gossipy Hen]] the latter is.
** Bart decapitating Ms. Hoover and Principal Skinner is pretty satisfying considering their actions in [[Recap/TheSimpsonsS6E6TreehouseOfHorrorV in "Nightmare Cafeteria".]]
* NarmCharm: "Moe Business" doesn't even try to hide the fact that it's just a musical theatre performance, so it comes off as a bit more humorous than the other segments, though there are still disturbing and horrific elements to it.
* NightmareFuel: Being a ''Treehouse of Horror'' episode, there's bound to be moments of this, such as Muncher Krusty attacking the camera and the scene of Homer impaled on the distiller.
* {{Squick}}:
** The burgers that start off the Muncher apocalypse are made from beef that is given to other cows and then repurposed into the burgers. Becomes more of Squick when it's referred to as the "Mad Cow" burger. What makes this worst, this is how real "Mad Cow Disease" happens, a cow being fed a meat-and-bone meal mixed in with the grain.
** Homer on the distiller, especially when he's wrinkly from being drained of blood. For that matter, the fact that people are drinking beer with Homer's blood in it.