Names like Christopher Guest, Chevy Chase, Bill Murray and Harold Ramis would come to define much of what American audiences consider the great comedies of the next several decades — and one thing they had in common was that they honed their improvisational techniques working on Lampoon projects like "Lemmings."
Decades later, many classic movie moments were the result of such training. In the "Animal House" cafeteria scene, when Belushi spits out his food and says "I'm a zit, get it?", he made it up on the spot; "Fletch," a non-"Lampoon" classic, was largely powered by Chase's off-the-cuff spontaneity. So were some of Bill Murray's best lines in "Tootsie" and, well, pretty much every other Bill Murray film.
The "Lampoon" films really gave these comedy greats full liberties to improv at will. Take, for instance, when the Griswold family has stopped for lunch at a rest stop in the original "Vacation," all digging into sandwiches that are conspicuously wet. As Ellen (Beverly D'Angelo) realizes Aunt Edna's (Imogene Coca) dog Dinky urinated on the picnic basket, Clark (Chase) notices the elusive girl in a red Ferrari (Christie Brinkley) off in the distance. The dance Clark does with his sandwich was completely improvised by Chase.
Then there's "Christmas Vacation," where Clark's famous meltdown about his boss (Brian Doyle-Murray, Bill's brother and similarly an early "Lampoon" favorite), was mostly ad-libbed — even if Chase's co-stars were wearing cue card-like signs to offer helpful suggestions for the 23 different adjectives ultimately woven together to describe him. When police invade the Griswold house and tell everyone to freeze, Beverly D'Angelo famously rests her hand on Chase's crotch; D'Angelo was more classically trained than her "Lampoon" co-stars, but the open-minded nature of such sets enabled such a moment of inspiration.
