A cute group costume for a set of three children who love the mischievous singing sensation Alvin and the Chipmunks is to dress as Alvin, Simon, and Theodore. Their costumes all roughly look the same and are actually quite easy to do thanks to their cartoon portrayal without much detail. They each wear a dominating color: Alvin red, Simon blue, and Theodore green. What separates them besides that is Alvin’s “A” letter on his sweater, and Simon’s big glasses since he is the older and smarter one of the three. Theodore is a bit more diminutive so if you have a shorter child he or she would be the perfect candidate!