The Box Jellyfish. Found primarily in the waters around Australia, the box jellyfish is one of the most venomous creatures known to man. Its tentacles are covered in thousands of nematocysts, which can inject venom capable of causing heart failure, paralysis, and even death within minutes. Swimmers,The Saltwater Crocodile. Ruling the rivers and coastal regions of Southeast Asia and Northern Australia, the saltwater crocodile is a master ambush predator. Capable of growing up to 23 feet long and weighing over a ton, they have the strongest bite of any living animal. These crocs will take down a