If you are making a ½ a batch of each then slice ½ of the brownie square and cut into small rectangles. I make mine about 4 x 6 cm. Melt the chocolate carefully in a bowl over a simmering pan of water. Don't let the children do this bit!
Using your fingers or a couple of forks, carefully coat the brownies in chocolate and set on a wire rack over a sheet pf baking paper to catch the chocolate drips. Sprinkle with milk chocolate sprinkles and fix a couple of candy eyes. Allow to set.
Using a round cutter (mine is 5 cm) cut out rounds of brownies and turn over to the soft side. Make 8 little cuts in the brownies for the legs/squirlies to go into. Push the legs gently into the holes. Support the brownies with your fingers as you do so.
Fix on a pair of candy eyes with some melted chocolate or icing and sprinkle with milk chocolate sprinkles.