A water horse is a make-believe creature from Scottish legends. It's like a horse, but it lives in the water. Instead of legs, it has a big tail like a fish, and it can swim really well. Some people think it can even breathe underwater!
Now, you might wonder why the water horse is important in Scottish legends. Well, people used to tell stories about it to teach children to be careful near the water. They said that the water horse would trick you into riding on its back, and then it would take you deep underwater and make you its prisoner! So, if you ever see a horse near water, be careful and stay away from it to keep yourself safe.
Of course, water horses aren't real, but they are still fun to imagine!