Do you think that if you've seen one horse, you've kinda seen them all? Well, you'd be wrong, because horses have a pretty wide range of sizes. Pictured is the world's largest horse and—if you look below that towering behemoth—the world's smallest horse. Talk about a size difference.The miniature horse, named Thumbelina (awww) is only 17 inches tall. The big one? Six feet, seven and a half inches. That's the average height of an NBA player. These horses are pretty awesome, but if you wanted to bet on kentucky derby races, it wouldn't be smart to put your money on either of these guys.How weird is that? A horse can only breathe through its nose, not through its mouth. Technically, if you covered a horses nostrils, it could suffocate (which is why those horse masks always have the nose uncovered). This explains why you never see horses panting like dogs when they're hot.Horses have a pretty insane field of vision—it's nearly 360 degrees, other than what's right in front of them, and directly behind them. They can actually look at two things at the same time.Sort of like dinosaurs, horses have tiny brains for how big they are—basically the size of a potato—but they have huge hearts, often weighing 10 pounds or more.Seriously, horses are basically big poop factories. A horse can make dookie up to 15 times per day. How often do you need to blast one out? Once a day? Once every other day? Imagine crapping 15 times in a single day.