Crocodiles and alligators are popular animals, both characterized by tough and scaly skin. Crocodiles are olive green or gray green with long, thin snouts. They are widely known as the ugliest animal of their species and they are the most dangerous too. Even huge animals, like hippopotamus, never mess with them. They vary in size considerably and the kind of species determines where they live. There are about 23 species spread across Malaysia, India, Pakistan, United States, Africa and Australia.