22. Seaweed
You may be laughing at the idea of seaweed being scary, but it’s actually quite dangerous. Number one, it can touch and grab your feet, scaring you half to death. Number two, it’s slimy and disgusting causing many people to actually fear it and refrain from swimming in waters with it. And number three, every year news outlets report people drowning after getting caught in it while swimming and diving. It may not seem like a threat, but it’s smart to look out for it next time you’re out in the ocean.