For the eyes: Place the malt balls cut side down on the work surface. Add a mini chocolate chip as a pupil to each ball by gluing with a little buttercream. Set aside.
For the mouths: Place the small orange gumdrops on the work surface standing upright. Snip each gumdrop with scissors straight down three-quarters of the way through the candy to make the open mouth.
For the tails and fins: Cut each orange gumdrop fruit slice in half horizontally to make 2 thinner slices. Cut 12 of these pieces in half crosswise to make fins. Make tails from the remaining 12 slices by cutting and removing a wide "V" into the concave side of the candy. Set aside.
For the stripes: Unroll the licorice and cut twelve 2 1/2-inch strips and twelve 3-inch strips. Separate the two sides of each strip.
To assemble: Frost each cupcake with about 2 tablespoons buttercream. Arrange a long and a short piece of licorice across one end of each cupcake, placing the longer piece toward the middle and the shorter piece toward the edge, about 1/4 inch apart to make a stripe. Repeat with another set of licorice pieces across the other end of the cupcake. Trim the licorice pieces so that they are even with the edges of the cupcake.
Attach the eyes, mouth, fins and tails by pressing gently into the frosting. Carefully sprinkle with orange nonpareils, leaving the 2 white stripes between the licorice pieces free of orange. Repeat steps for all cupcakes.
Use a fine, serrated blade to make a clean edge when slicing through the malted-milk-ball fish eyes.