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Harold Ramis played the quintessential role of Egon Spengler in Ghostbusters, donning the mantle of a brilliant nuclear physicist and parapsychologist, with a penchant for deadpan humor. Egon, renowned for his meticulous research, specialized in the detection and identification of paranormal entities. His signature catchphrase, "Never cross the streams," has become ingrained in popular culture, highlighting his expertise and the comedic undertones of the iconic film.