Philosophers will tell you that identity is a shifting, overdetermined, social construction, but the identity of a football team consists of something slightly more concrete, molded from a combination of the franchise's best players and a consensus narrative about the nature of the team's play.
Whether it's the Purple People Eaters or The Greatest Show on Turf, some identities leave a lasting impression. For these eight teams, they're all looking either to return to the successful dynamic of a previous identity or break out from the nondescript doldrums that go along with, say, losing 14 games and getting the top pick.