Halloween Rice Crispy Treats (Frankenstein's Monster!)

Spray bottom and sides of 13 x 9-inch pan with baking spray. In large pot, melt butter over medium-low heat.
Add marshmallows, salt and enough food coloring to make the mixture bright green and stir until full combined and smooth. Assess the color and stir in more food coloring if you need to.
Remove from heat. Add Rice Krispies and stir until cereal is fully coated in marshmallow mixture.
Transfer the mixture to prepared pan, using a piece of parchment paper or greased hands to press the mixture against bottom of pan.
Let stand at room temperature 15 minutes.
Turn out onto cutting board and cut rectangle in half lengthwise. Cut each half into 5 pieces crosswise.
Place chocolate in microwave-safe glass measuring cup or other glass or bowl that the treats will fit into for dunking, and microwave in 30 second intervals until smooth, stirring between each interval.
Dip one end of each treat in melted chocolate and place on parchment paper. Immediately sprinkle chocolate with sprinkles.
Use remaining melted chocolate to attach candy eyeballs and mini peanut butter cups as neck bolts.
Use black writing gel to add mouths and stitches, and red writing gel to add a bit of “blood,” if desired.