Last Crusade's prologue establishes that Indiana got the famous scar on his chin when he clumsily cracked a whip at a circus lion. In real life, Harrison Ford acquired it in a car accident when he was 20. No, a lion wasn't behind the wheel. (Source)

Although he played Harrison Ford's dad in the film, Sean Connery was only 12 years older than his on-screen son. At the time of filming, Ford was 47, and Connery was 59. (Source)

While filming the zeppelin scenes, Harrison Ford and Sean Connery both took their pants off because it was so hot. Really adds a new level of poignancy to their whole father-son chat, doesn't it? (Source)

Although it looks a little silly by today's CGI standards, Donovan's gruesome death scene set a new standard for digital effects back in 1989. It was the first digital composite shot, meaning that they took a bunch of shots of Donovan (Julian Glover) at various points in the rapid-aging process, threw in some puppets for the worst of the decomposition, and then spliced it all together into the final, ghastly shot. (Source)

Turns out Indiana was named after a dog: executive producer George Lucas' Alaskan malamute. He was originally called Indiana Smith, though—until Lucas wisely decided that Jones sounded cooler. (Source)

Ready for your skin to crawl? The production crew specially bred 2,000 rats for the Venice catacombs scene, since regular rats would have carried diseases. But don't worry, rodent lovers: when the catacombs go up in flames, they used 1,000 mechanical rats. (Source)