The animatronic robotic T-Rex was covered in a “skin” that soaked up water, and this would make it malfunction. As the T-Rex was in a lot of scenes with rain, this led to some memorable moments for the crew. And because at first, they didn’t know what was causing the malfunction, some people got a big scare on set.

Producer Kathleen Kennedy described it like “The T-Rex went into the heebie-jeebies sometimes. Scared the cr#p 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.”