#1 Crocodiles
This is the closest you'll get to meeting a dinosaur, and frankly, why would you want to? Just stay out of the water. They can grow up to 20 feet long and 2000 pounds heavy.
#2 Basking Shark
Basking sharks mostly eat plankton, but you still wouldn't want to be confronted with this beast. Look at it! That mouth OMG! Stay out of the sea I am telling you.
#3 Giant squids
Mystery surrounds this gross-looking monster. Little is known about the giant squid, but the largest one ever found was about the size of a bus. It will snatch you up and take you to the deepest darkest part of the ocean. Why would you want that? Just stay out of the ocean.
#4 Giant Pacific Octopus
The giant Pacific octopus is the largest species of octopus in the world. It can stretch out to 20 feet and it's great at camouflage. It will wrap itself around you, is that what you want?! BTW is that diver hugging it?
#5 Humpback whales
While whales have a friendly nature, they're still massive 30 ton beasts and you don't want one landing on your boat after a beautiful aerial display. Do you want your boat to capsize? No? Don't take it out in the middle of the ocean, where the humpback whales live. Got it?
#6 Stingrays
Stingrays are quite lazy in nature, but if they feel threatened, you don't want to be around. They will protect themselves with their poisonous stinger. If you don't know, it killed Steve Irwin.
#7 Anacondas
If it's scary enough to make a film series about it, you don't want to be in the water with it. This giant snake lives in the waters of South Africa and is the largest, heaviest snake in the world. Don't worry about being poisoned though, it can't do that. All it does is wrap around you and cut off the blood circulation to your brain and drown you.
#8
Although this one looks Photoshopped, still stay away from water.
#9 Whale Sharks
The largest fish in the world. Whale sharks usually feed on plankton, but do you really think they're going to be bothered by a lost little human in their mouths? No. No they won't. In fact, they probably think you are delicious. Now get out of the water!
#10 Nomura’s Jellyfish
The Nomura jellyfish is generally found in Japan and it is HUGE. Its diameter is larger than the average human. It's also venomous, so yeah, stay out of those Japanese waters, OK?
#11 Swordfish
Oh come on, this fish is a weapon! They're not known to attack people unprovoked but that doesn't mean they haven't.
#12 Great White Shark
Of course we weren't going to leave out Jaws. Unlike whales, sharks LOVE some meat and they don't shy away from attacking humans. In fact, they do so five to ten times a year.
#13
See? Pro surfer Mick Fanning actually escaped a shark attack during a competition that was broadcasted live.
#14 The Mantis Shrimp
OK, "shrimp" doesn't sound scary but "mantis" does. So does "clubs". What are clubs, you ask? Oh just, what the mantis shrimp uses to break aquarium glass. Or, you know, your face. No swimming for you.
#15 Killer Seaweed
Yes. Killer seaweed. It's not even alive and it wants to kill you. In fact, these seaweed forests are the kind that divers get caught in and drown.
