Prepare the Pan: Grease a 9x13-inch baking dish or line it with parchment paper.

Melt Butter and Marshmallows: In a large pot, melt butter over low heat. Add marshmallows and stir until smooth.

Add Food Coloring: Stir in green food coloring until you reach a Frankenstein shade.

Mix in Cereal: Remove from heat and stir in Rice Krispies until fully coated.

Press Into Pan: Press mixture evenly into the prepared pan. Let cool for about 10 minutes.

Cut Shapes: Once set, cut into rectangles to form Frankenstein heads.

Decorate: Melt chocolate chips and dip the top of each rectangle to make Frankenstein’s “hair.” Press candy eyes onto the face while chocolate is still soft. Use black gel to draw a stitched mouth and scars. Insert pretzel sticks or Tootsie Rolls into sides for “neck bolts.”

Set and Serve: Let decorations firm up, then serve.