Here’s a rough idea for characters:

Monster
Evil Guy(villain)
Trick or Treater #1(Hero)
Trick or Treater #2(Hero)
Trick or Treater #3(monster food)
Trick or Treater #4(monster food)

We will use the rough story I posted above.

My first idea, which uses a story from Mary’s sister:

There is a house with a nasty surprise in the basement. Living in the basement is a creature; every couple of years this creature needs to feed. The beast also cannot come out in the light. So it has to feed in the dark. The owner of the house knows about the creature, and not wanting to become the monsters dinner, helps the creature out. This Halloween the beast needs to feed. So the owner decides to send trick or treaters down to the monster.
The owner captures 3 or 4 trick or treaters, not knowing how much the beast will eat. He sends 2 into the basement and shuts the light off. Screaming, splatting and crunching noises come from the basement. Our 2 protagonists are the remaining 2 that were captured. They make a valiant effort to escape, but to no avail. They are thrust into the basement.
The owner shuts the door and the lights go out…but nothing happens. The owner yells to the beast saying there are 2 more entrees. But still nothing. Thinking the beast is no longer hungry, he turns on the light and goes in to check the heroes. Seeing they are still alive he tells them not to move. He then starts to do a quick check of the basement. As the guy moves past them, the 2 heroes bolt for the door. They make it out and slam the door shut just as the guy almost reaches them. They quickly shut the light out and the gruesome noises ensue.
The owner never realized the 2 heroes had glowsticks that were protecting them from the beast.

The End…