My best friend that year and I both had similar boxes for our school party: big cardboard boxes wrapped in brown paper, painted-on eyes, big mouth hole for collecting valentines, a pom-pom for hair, and one of my hippie dresses for clothes. Every year in elementary school we had Valentine's Day parties where everyone would decorate their own box at home and bring it into school.
Everyone would get a list of the names of everyone in the class, and you were supposed to give everyone a valentine's card with some sort of candy. We would all walk around to the boxes delivering our cards and candy, and then have a feast of sugar afterwards. And probably watch a movie or something. Back when Valentine's Day was exciting and fun!