Add marshmallows, and stir constantly until marshmallows have melted.
Remove from heat, and stir in vanilla.
Add popcorn, and fold into marshmallow mixture.
Lightly spray your hands with nonstick cooking spray.
Scoop about 1 cup of the popcorn mixture and smoosh it into a ball.
Roll the popcorn ball in the crushed Oreo cookie crumbs.
Press cut worm halves into the popcorn ball with the rounded end of the work coming out of the popcorn ball.
Place on a sheet of waxed paper, parchment paper, or silicone baking mat to cool.
When cool, press a stick into the center of each popcorn ball.
Notes
Butter: I use salted butter in this recipe.
Marshmallows: Mini or regular marshmallows will work.
Popcorn: Be sure to pick out any kernels before using. Any type of plain popcorn - air-popped, microwave, etc., will work.
Oreo cookie crumbs: I use about half of a 10 ounce package. I like to use the cookies with dark chocolate filling. They give a darker coating for the popcorn balls.