In Elf, the street scenes were actually shot in the middle of New York City using real New Yorkers, because the production worked with a small movie budget and did not fill the sidewalks with paid extras. What you see on screen are real city pedestrians moving around Will Ferrell in full elf costume. The hilarious line "You smell like beef and cheese; you don't smell like Santa" was completely off the cuff and unscripted.
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