This short, pudgy and balding (as well as maniacally energetic) character player is best known as George Costanza, the worrisome comic foil to straitlaced Jerry Seinfeld, on the hit TV series "Seinfeld" (NBC, 1989-98). But Alexander has been a very busy and very versatile actor since the 1980s, beginning in children's theater and TV commercials. He received early breaks when cast in the telepic "Senior Trip!" (CBS, 1981) and the slasher film "The Burning" (1981)....