Whale tail

Okay, so imagine a really big animal called a whale that lives in the ocean. Now, sometimes when whales swim really fast, their tail goes up in the air before going back in the water. This part of the tail that sticks up is called the "whale tail". People might sometimes see this and get excited because it's a cool thing to see! Some people even say that it's good luck to see a whale tail. But it's important to remember to be careful and respectful around whales, because they are wild animals and we don't want to disturb them.