14. Rhinoceros
There are many kinds of rhinos in the world, but the Western rhino is known to be the most aggressive of them all. They use their horns to attack and kill their prey, but their aggressiveness is mostly triggered by confusion, fear, or panic. But they are also one of the most endangered animals as well, as they often get hunted for their horns. The last remaining white rhino is being kept under guard by armed men too so no hunter can go near it, so it gives you an idea of how endangered they are.
