In a mixing bowl stir together peanut butter and butter until creamy.
Gradually add powdered sugar, stirring until combined.
Stir in Butterfinger candy.
Shape into 1-inch balls; place on waxed paper.
Freeze about 45 minutes.
Melt white chocolate in a double boiler or get a med sauce pan filled 1/4 of the way with water and heat until simmering and place a large glass or stainless steel bowl over top and turn heat off -if water is boiling it will scorch chocolate.
Add chocolate to bowl, stir constantly until melted and smooth, if you want the coating thinner add a Tbs shortening until desired thickness is reached.
Dip balls, one at a time, into coating. Let excess coating drip off
Place on waxed paper, immediately press an M&M onto center of each peanut butter ball (you can also wait to put M&M's on until after set and just use a dot of your piped colored chocolate to adhere)
Refrigerate until coating is firm.
Using leftover white chocolate add red food coloring until desired color is reached (you may have to reheat) and place in a ziploc or pastry bag,cut a corner very small, pipe squiggly lines on eyes to make them look blood shot or use red decorating gel.
Add a dot of black gel or black food colored coating to the center of M&M pieces for pupils.