Place medium brown buttercream into a piping bag fitted with #233 piping tip. Pipe short, vertical dollops of buttercream all over the surface of the cupcake, then larger dollops of buttercream for the ears. Pipe a final, generous dollop of buttercream in the center for the nose. Use a mini chocolate chip for the nose, 2 regular chocolate chips for the eyes and a flattened piece of pink starburst for the tongue.