Anna the Red, the internet's resident Queen of Bento, has created an elaborate Halloween Bento Box based on video game Costume Quest: "an adorable role-playing adventure game created by Double Fine. It takes place on Halloween night, kids in costume trick-or-treating and fighting monsters to save a kidnapped sibling while collecting costumes."
Pretty amazing, huh? For the ambitious: although it isn't a straightforward HowTo, Anna has described her process in great detail. You can do it! (P.S. If you're looking for something simpler, check out Cool Mom From Vancouver's tombstone and coffin sandwiches):