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16. The decision to kill off George's fiancee Susan at the end of the show's seventh season (by licking poisonous envelopes, no less) came from a rather unlikely place: Louis-Dreyfus. As Alexander explained it during a 2015 interview with Howard Stern, the actress who played Susan, Heidi Swedberg, had comedic instincts that clashed with his. "I couldn't figure out how to play off of her," he said, adding that by the time Seinfeld and JLD shared scenes with her, they came to the same conclusion. "They go, 'You know what? It's f--king impossible. It's impossible,'" he said, while stressing that he had nothing against Swedberg personally. "And Julia actually said, 'Don't you want to just kill her?' And Larry went, 'Ka-bang!'"
17. The cast found themselves in a bizarre feud with Roseanne Barr and her then-husband Tom Arnold when Louis-Dreyfus inadvertently parked in Arnold's parking spot on the CBS lot where both shows filmed. He left a note on her windshield that read "How stupid are you? Move your f--king car, you asshole!" which promoted the actress, alongside Alexander and David to confront him. After their encounter, she later found "a Polaroid of someone's buttocks left on her windshield and the word 'c--t' written in soap." Barr then took the feud public, calling JLD a bitch during an appearance on David Letterman's late-night show, adding derisively, "They think they're doing Samuel Beckett instead of a sitcom." As quoted in Seinfeldia, when Alexander was asked about the comment, he replied, "I am willing to bet that she has never read anything Beckett ever wrote."
18. Before Seinfeld landed on Junior Mints as Kramer's candy of choice for the iconic episode "The Junior Mint," it was originally intended for him to drop popcorn into the patient whose surgery he was watching. "I was on the phone with my brother, running the story by him, and he said, ‘No, make it Junior Mints because it's funnier,'" writer Andy Robin told HuffPost in 2015.