Animals·Posted on Jul 3, 202111 Extremely Unsettling Facts About Jellyfish That Just Might Mess You UpI'm scared a jellyfish is going to beat me up for writing this.by Kelly MartinezBuzzFeed StaffFacebookPinterestTwitterMailLink Hello, good people of the internet. Do you know what the most terrifying sea creature is? Tap to play GIF Tap to play GIF Nickelodeon "A shark*," you confidently answer with a light chuckle. Alastair Pollock Photography / Getty Images *Despite their reputation, most sharks are actually not a danger to humans! WRONG. IT'S THIS GUY RIGHT HERE. Schatzif / Getty Images/ iStockphoto "But...that's just a jellyfish," you whimper, confused. Netflix Yes, jellyfish are beautiful! But they're also SCARY AS HELL. Allow me to explain: 1. First of all, they literally do not have brains. They're just out here swimming around with ZERO brain cells. Getty Images 2. They don't have hearts either. Getty Images 3. They are literally just 95 fucking percent water!!! NBC / Getty Images 4. They can still sting you even after they're DEAD. Cavan Images / Getty Images / Cavan Images RF 5. Some jellyfish have teeth!!! Lagunatic Photo / Getty Images / iStockphoto Beroid comb jellyfish have hundreds of small rows of cilia in their mouths that act as teeth and help them chew their prey. 6. One type of jellyfish can actually reverse age. Duangkamon Panyapatiphan / Getty Images/ iStockphoto Turritopsis nutricula, better known as the "immortal jellyfish," can alter and transform its cells to go from adult to baby and back again. Because jellyfish just HAVE to live forever, don't they?! 7. Know what the most venomous marine animal is? Surprise — it's a type of JELLYFISH! Humberto Ramirez / Getty Images More specifically, it's the Australian Box Jellyfish. According to the National Ocean Service: "Box jellyfish, named for their body shape, have tentacles covered in biological booby traps known as nematocysts — tiny darts loaded with poison. People and animals unfortunate enough to be injected with this poison may experience paralysis, cardiac arrest, and even death, all within a few minutes of being stung." Holy. CRAP. 8. In fact, box jellyfish have tentacles than reach up to 10 freakin' feet long. Scared yet? Tap to play GIF Tap to play GIF Nickelodeon Yes, I know Squidward is an octopus. Hush. 9. But that's not the biggest jellyfish — that's actually the Lion’s Mane Jellyfish, which has been recorded to reach 120 feet long. Stuart Westmorland / Getty Images This is fine. I'm fine. 10. Still not freaked out? What if I told you that a group of jellyfish is powerful enough to take down an entire 10-ton fishing boat? Tap to play GIF Tap to play GIF Disney Yes, that really happened. 11. And finally, jellyfish sometimes just casually eat each other. Tap to play GIF Tap to play GIF TVPeru They're heartless, remember? Jellyfish, you absolute MONSTERS. Nickelodeon That being said, they're still very important to our ecosystem! To learn more, click here.