These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: It's the Great Pumpkin, Charlie Brown
Awesome Music: Vince Guaraldi's score (again), highlighted by the "Great Pumpkin Waltz". Also, the reprise of "Linus and Lucy" from A Charlie Brown Christmas is even better with that little flute bit added.
Narm Charm: Some of the children providing the voices were too young to understand their lines, resulting in the classic awkward delivery that later became a staple of all Peanuts specials (the lines you hear are often a composite patched together from several different takes).
Nightmare Fuel: The whole "Snoopy behind enemy lines" sequence. That eerie flute music (coupled with the air-raid siren) doesn't help.
Not to mention the opening title sequence. Completely justified, of course, since this is a Halloween Special we're talking about.