Harold Allen Ramis /ˈreɪmɪs/ was an American actor, director, writer, and comedian. His best-known film acting roles were as Egon Spengler in Ghostbusters and Ghostbusters II and Russell Ziskey in Stripes ; he also co-wrote those films. As a director, his films include the comedies Caddyshack , National Lampoon's Vacation , Groundhog Day , and Analyze This . Ramis was the original head writer of the television series SCTV, on which he also performed, as well as a co-writer of Groundhog Day and National Lampoon's Animal House . The final film that he wrote, produced, directed and acted in was Year One .