After Clark gets pulled over in Colorado, the police officer asks him to get out of the car, and shows him Dinky's (Aunt Edna's dog) leash tied to the rear bumper of the car.
Apparently, Clark had forgotten to untie the dog from the bumper before they left the campground earlier that morning. Dinky was dragged along behind the car, causing him to die.
While most fans have every line from "National Lampoon's Vacation" memorized, it turns out some of the behind-the-scenes moments are just as memorable. Here are 20 things you probably didn't know about the original "Vacation" shared by Today.com.
Check out these 14 Road-Worthy Facts About National Lampoon's Vacation shared by Mentalfloss.com.
Get National Lampoon's Vacation summary of box office results, charts and release information and related links at Boxofficemojo.com.