Line a large baking sheet with parchment paper; set aside.
Add the popcorn, Chex cereal, pretzel pieces, candy corn, and mini M&Ms to a very large mixing bowl.
Melt the candy melts according to package directions until completely smooth.
Drizzle candy melts over the popcorn mixture, then using a spatula, quickly (but gently) stir and fold until all the ingredients are coated.
Transfer the mixture to the lined baking sheet, spreading it out to an even layer.
Place in the refrigerator to completely dry and set, 30-60 minutes.
Break into snack-size pieces and serve in cute Halloween cupcake liners or package up in cellophane bags for a cute party favor.
Notes
Storage. This Monster Munch can be stored at room temperature in a sealed container for up to 5 days.Variations. Possible variations are included in the article.