In a large glass bowl, melt together marshmallows and butter in microwave until they stir smooth. This will depend on your microwave but should take somewhere between 30-45 seconds.
Stir in cereal.
Scoop mixture into greased pan and press down to form bars. (I like to spray the bottom of a measuring cup with nonstick spray and use that to press the mixture down so it doesn’t stick to my hands.)
Allow bars to cool and set, then cut into pieces the size you’d like.
Slowly melt the blue candy melts in a glass bowl in the microwave. I like to start with a 30 second burst, then do 15 second bursts after that. Stir well after each trip to the microwave and stop as soon as it stirs smooth. Be careful not to scorch the chocolate.
Dip one side of each rice crispy treat into the melted chocolate. You can leave a smooth finish or add texture with a spatula or knife. Affix eyeballs and allow to set.
Store in an airtight container until ready to serve.