19. Box jellyfish

It’s estimated that around a hundred people die each year from box jellyfish stings, which each have enough venom to kill about 60 people. These 24-eyed marine creatures inject toxins into people’s blood, causing their heart to stop. Although some people die a different way; they go into shock and drown because the pain is so intense.

However, some people stung by them don’t actually die, if they get to shore and treatment in time. The most deadly species of box jellyfish live around Australia, but some live near Hawaii and Florida. They’re 10 feet tall, because their 15 tentacles are so long. Nemo’s dad was very lucky that the jellyfish he encountered were not the deadly box jellyfish.