A Lion Lunged at Bob Denver
In one episode of the series, Gilligan (Bob Denver) finds himself trapped inside a hut with a lion. Working with any wild animal can be dangerous, and the lion on set was ferocious. Even the trainer was covered in marks, which is never a good sign when you have to be in close quarters with an animal.
Source: YouTube
When it was time for Denver to film his scene with the lion, the animal lunged at him. He instinctively karate chopped the wild cat. Luckily, the trainer ran on to the set to tackle the lion mid-leap. That animal could have been the end of Gilligan.