Cosmo Kramer's Original Name On Seinfeld, Explained

Before Michael Richards played Kramer on NBC's "Seinfeld," he played Kessler. This early version of the character behaved nearly the same as Kramer, but he was agoraphobic, he owned a retriever named Ralph, and his apartment was not yet located right across the hall from Jerry's. The name Kessler only lasted for the pilot, which aired under the title "The Seinfeld Chronicles" almost a year before the rest of the first season aired. 

In a behind-the-scenes featurette, co-creator Larry David explained that Kessler was based on his real-life neighbor Kenny Kramer. "I knew that by calling this character Kramer it was gonna open a whole can of worms that I don't want to get involved in," David said. Co-creator Jerry Seinfeld confirmed David's story: "Larry ... correctly predicted that if we involved Kenny Kramer in any way in this show, he will exploit it to the maximum and become a complete pain." 

Not long after "Seinfeld" became a hit, the real Kenny Kramer started a business exploiting his TV counterpart, offering bus tours and wedding officiations. He also twice used his Kramer connection to run for New York City mayor. For Seinfeld at least, all this chaos was worth it: "That name just had something that no other name had," Seinfeld recalled. "I said, 'We have to change it to Kramer. There's no other name. There's just something in that name that rings true.'"

Kramer's first name, Cosmo, wasn't revealed until the Season 6 episode "The Switch," but that wasn't the show's first choice, either. In a Season 2 episode that was scrapped, partly due to a dark JFK assassination joke, the show reveals Kramer's name as Conrad. "I was kind of thinking of Conrad Birdie from 'Bye Bye Birdie,'" the episode's writer Larry Charles revealed in a 2014 interview. He recalled having "mixed feelings" about the eventual change to Cosmo but admitted it was "a great name" for the character.

The Cosmo reveal served as a payoff to years of fan speculation. Kramer confessed in the episode, "All my life I've been running away from that name!"

The show did not turn Kramer's post-pilot name change into its own long-running mystery, but it did offer an explanation for it in Season 9's "The Betrayal." The late-series episode featured a flashback scene showing Jerry and Kramer's first-ever conversation. "I saw your name on the buzzer, you must be Kessler," Jerry says, talking to his new neighbor in the hallway. "Actually, it's Kramer," Kramer replies, receiving a few knowing laughs from the audience.