Box Jellyfish
Jellyfish are known for their poisonous tentacles that can cause a killer sting. Their stings leave scars and can leave on the injury on a human body for days and weeks. But that’s a normal jellyfish. Box jellyfish are an entirely different story. These jellyfish float around in the tropical ocean, mainly where the Indian Ocean meets the Pacific ocean. Luckily, they can only swim five miles per hour, but that doesn’t make them any less dangerous.

Their tentacles can grow up to 10 feet long, so even if you don’t think you’re near one, there’s the chance you’ll swim directly through their tentacles. These contain thousands of stinging cells that carry a toxic poison that affects the nervous system, skin, and heart. It causes paralysis, cardiac arrest, and death. If you’re a young child or the elderly, there’s a high chance you’ll die from the sting alone. Even though an anti-venom exists, it’s unlikely you’ll receive treatment on time, since you’ll be dead before you even get to the hospital (Flamingoof).