Melt the butter over a medium heat in a large pot. Sift in the matcha and mix until well combined. Add in the bag of marshmallows and mix until melted. Add in the rice cereal and mix to combine. Pour onto a tin foil lined tray (9x13) that is greased. Chill for 30 minutes and slice into squares. Melt candy melts in the microwave (in 30 second intervals) or over a double boiler. Dip the treats into the candy melts, lay on a parchment lined baking sheet. Decorate with candy eyes. Chill until candy melts have hardened, about 30 mins.
