• Spray a 9x13 glass baking dish and set aside.
• Preheat a large pot to medium and melt 4 tablespoons of butter.
• Once the butter is melted, add all 5 cups of marshmallows and stir to coat with the melted butter. Continue to stir the marshmallows until they are completely melted.
• Turn off the heat and quickly stir in the Rice Krispies. As soon as they are evenly mixed, pour the Rice Krispie and marshmallow mixture into your dish.
• Cover the Rice Krispie treats with a piece of plastic wrap and really press into them to create a very even thickness all the way through. Having a nice even layer will give you uniform Rice Krispie Treats. Let them rest for at least two hours before cutting and decorating.

Decorating

• Run a knife around the edges of the Rice Krispie Treats and flip over onto a cutting board. Cut out 12 equally sized treats. Trim the edges so they have straight sides all the way around.
• Place chcolate melts in a microwave safe dish and heat in mocrowave on "MELT" setting. Stir vigorously every 30 seconds until the chocolate is smooth. The more you stir, the less heat you will have to use overall. Be careful and watch the temperature because if the chocolate gets too hot, the sugar will burn and you'll have to start over.
• Transfer the colors to plastic piping bags for the decorations. If the chocolate hardens, you can place the piping bag back in the microwave for 30 seconds to re-melt the chocolate.
• For the mummy, start with a small section ⅓ of the way from the top of your treat and pipe out a little chocolate. Stick on two candy eyes in the stripe. Use the white chocolate to pipe on stripes, making some horizontal and some diagonal to look like a wrapped mummy.
• For Frankenstein, start with a lot of green chocolate for the base. When you have piped out a thick layer, tap the Rice Krispie Treat down on your work surface to smooth it out. Put on two candy eyes. Use the dark chocolate to give him hair and a mouth that looks like stitches. Dip two mini marshmallows in chocolate and secure to the sides for the "bolts."
• For the Jack-O-Lantern, start with a base layer of orange. Tap it on the counter to smooth it out. Using melted dark chocolate in a piping bag, give it triangle shaped eyes, nose, and Jack-O-Lantern mouth.
• They are ready to serve or you can bag them up for later. They travel well.