In 1989, the balding actor joined the cast of "Seinfeld" and quickly became a household name by delivering endlessly quotable dialogue with a neuroticism that was pure George Costanza. During Alexander's nine-year stint on the popular sitcom -- a fruitful period that brought him seven consecutive Emmy nominations -- he also appeared on the big screen in Pretty Woman (1990) and Coneheads (1993).
Alexander's later projects of note include a wicked turn as Boris Badenov in The Adventures of Rocky & Bullwinkle (2000); Shallow Hal (2001, opposite Jack Black); The Aristocrats (2005); and voice work in Farce of the Penguins (2007).