Deep underwater where nobody goes there is a world of creatures . From small fish to tall fish round fish brown fish but worst of all crocodiles not just normal crocodiles but purple crocodiles purple crocodiles are the worst type they have the worst killer instinct . Proffesers are starting to think they may be the animal that has killed the ost thing that has ever walked the planet . It is difficult for scientists because they can not study underwater . Purple crocodiles have twisted tails and a scary appearance they are terrifying     underwater creatures that will roam the earth for years .