We didn't make a big deal out of Groundhog Day - no pop-up craft or elaborate shadow play. We did have flashlights, black sheets and a white board for making shadows all week at stations. For the last two days we read our groundhog books and good ol' Let's Find Out magazine had a groundhog book. I did add a little groundhog to our phonics and spelling practice though. Our mystery word lesson starts with a strip of letters. The students cut apart the letters and line them up across the top of a work "mat." Today the mat had a picture of a groundhog. I gave clues / hints to indicate what word to build with the letters. I often give the answer to the clue if needed and I model the word on the document camera after allowing enough time for students to work on their own. After a series of words we build up to the mystery word. Today the kids were super proud because they "guessed" and spelled GROUNDHOG! Most of the FDKers chose to take home their letters in bags to rebuild with later. Some kids glued the word groundhog on top of the page before coloring it.
I have the Valentine and Groundhog mystery word directions at my TPT store: Groundhog and Valentine Mystery Word lessons I hope to add some other mystery word lessons soon.