So, I'm still on the idea of "This Is Halloween" set to this episode (and a few others), and I sort of went through the lyrics and tried to think of what imagery from the episodes would go best in which places. I don't have everything yet (some of the more general chorus stuff eludes me, as well as some of the "I am" lines), but maybe you'd like to see what I've got so far.
Sadly, I don't think I quite have the equipment or practice to make the video myself. I could try, of course, but I'm not sure where, for example, I'd get a good-quality version of the episodes, or how to edit them.
Anyway. Just to warn you, the lyrics are a bit of a wall of text. I'll wall them off in a quote-block because I can't fit them into a single hottip.
Boys and girls of every age / Wouldn't you like to see something strange? (Zecora speaking to the children before the trip)
Come with us and you will see / This, our town of Halloween (Wide shot of the town as the festivities are going on)
This is Halloween, this is Halloween / Pumpkins scream in the dead of night
This is Halloween, everybody make a scene (Pinkie and the gang running off)
Trick or treat till the neighbors gonna die of fright (The trick-or-treaters)
It's our town, everybody scream / In this town of Halloween
I am the one hiding under your bed / Teeth ground sharp and eyes glowing red
I am the one hiding under yours stairs / Fingers like snakes and spiders in my hair
This is Halloween, this is Halloween / Halloween! Halloween! Halloween! Halloween! / In this town we call home / Everyone hail to the pumpkin song
In this town, don't we love it now? / Everybody's waiting for the next surprise (The mayor's first speech)
Round that corner, man hiding in the trash can / Something's waiting now to pounce, and how you'll... (Twilight jumping Pinkie)
Scream! This is Halloween / Red 'n' black, slimy green
Aren't you scared? / Well, that's just fine (Dash. Have her storm-cloud flashes occur on "scared?" and "fine")
Say it once, say it twice / Take a chance and roll the dice
Ride with the moon in the dead of night (Chariot)
Everybody scream, everbody scream (Pinkie and the gang X2)
In our town of Halloween! (wide-shot)
I am the clown with the tear-away face (Discord putting his face on a balloon...)
Here in a flash and gone without a trace (And vanishing)
I am the "who" when you call, "Who's there?" / I am the wind blowing through your hair (Owl)
I am the shadow on the moon at night / Filling your dreams to the brim with fright (Luna doing her "Nightmare Moon with vampire fangs" schtick)
This is Halloween, this is Halloween / Halloween! Halloween! Halloween! Halloween! / Halloween! Halloween! (Not sure. More shots of the town? Spider-incident?)
Tender lumplings everywhere / Life's no fun without a good scare (Zecora's little magical scare-show)
That's our job, but we're not mean / In our town of Halloween (Luna trying to be nice)
In this town Don't we love it now? / Everybody's waiting for the next surprise (Mayor's second speech)
Skeleton Jack might catch you in the back / And scream like a banshee / Make you jump out of your skin (Luna with her huge voice, startling people ("Scream like a banshee", you see?))
This is Halloween, everyone scream / Wont' ya please make way for a very special guy (Her big entrance into the town)
Our man jack is King of the Pumpkin patch / Everyone hail to the Pumpkin King now! (Luna being impressive and intimidating. Lighting mandatory)
This is Halloween, this is Halloween / Halloween! Halloween! Halloween! Halloween!
In this town we call home / Everyone hail to the pumpkin song
La la la la-la la [Repeat]