Friday marks the re-release of Jurassic Park in 3D—a worthy use of the form—and in honor of the film's 20th anniversary Entertainment Weekly has put together a fun oral history of Steven Spielberg's classic blockbuster, which reveals that the iconic puppet playing the iconic T. Rex had something of a mind of its own. 

You see, the rain in the iconic scene where the T. Rex attacks the Ford Explorer made the T. Rex puppet kind of freak out, puppeteer John Rosengrant explained: 

The T. rex was 36 feet long and 18 feet tall. We’re talking about a hydraulically powered creature that felt like a bus going by you when it would move. We found out not long before we were going to shoot that it was going to be raining [in the scene]. So it went from this beautifully tuned machine that worked fantastically to… suddenly the foam-rubber skin started absorbing water, and now all of the calculations were off and it started to shudder. We went out and bought tons of towels and started putting big blowers, dryers, on it to dry it out.

The hitch in the system made the T. Rex have what producer Kathleen Kennedy described as, well, its own new life:

The T. rex went into the heebie-jeebies sometimes. Scared the crap out of us. We’d be, like, eating lunch, and all of a sudden a T. rex would come alive. At first we didn’t know what was happening, and then we realized it was the rain. You’d hear people start screaming.

Um, yeah. Considering that thing plays a role in one of the most terrifying scenes in movie history, we'd scream, too.

Read the rest of the oral history here, and go ahead and watch that scene, why don't you. We know you want to: