For the longest time I was convinced as a child they kept the sharks caged under the large metal grill at the bottom of the deep end of the city pool. Nobody would correct me. So when the lifeguards blew the whistle for everyone to get out... zoom.

When our kids were really young and were rambunctious, we would make scratching noises on the side of the car door while we were driving, and we'd warn the kids in hushed tones that it was the "Angry Monkeys" trying to get in the car. It later became an inside joke, but for some bizzare reason in child-world the whole concept of angry monkeys worked. Must have been their exposure to the winged monkeys in the Wizard of Oz.