Seinfeld had another "real" George Costanza (Jason Alexander) besides the sitcom's co-creator Larry David. Given that Seinfeld was a sitcom about the fictionalized life of stand-up comedian Jerry Seinfeld, it's unsurprising that some of the characters were also based on real people. For example, Cosmo Kramer (Michael Richards) was based on Larry David's neighbor, Kenny Kramer, who went on to use the connection to his advantage by hosting Kramer's Reality Tour, an open-top bus tour of famous Seinfeld locations.
