Here's a really professional Mario bento box. The face is molded fried rice balls. The black parts are nori seaweed. The red is kameboko(fish paste cakes) but you can substitute crab sticks. Use sliced cheese for the white parts. For the blue, mix blue food coloring with egg whites and make an egg sheet to wrap the rice balls. Use green olives with yellow picks for the buttons. The shoes are thick beef sticks. It might take a little work, but worth the effort.
Tokyo Otaku Mode