The Earth's deep waters hide some of the most mysterious, horrifying, but at the same time, unique and fascinating creatures. According to scientists, the estimated number of animals living in the ocean is about one million, which is unbelievable! The English broadcaster and natural historian, Sir David Attenborough, says in the BBC documentary series "Blue Planet II": "The oceans cover 70% of the surface of our planet, and yet they are still the least explored." That's why we've singled out the most fascinating ones and decided to make a top ten list of strangest water creatures whose appearance will most certainly intrigue you. Also, check out our Top 10 Most Peculiar Earth Creatures That You Won't Believe Exist

10. Polka Dot Nudibranch

The common nudibranch's appearance may not look spectacular, but Jorunna funebris, aka the dotted or polka-dotted nudibranch, will. They have a chubby oval body with white and black round markings, occurring in a wide variety of unusual colors and forms. 

Moreover, scuba divers instantly fall in love with polka-dotted nudibranch since it reminds some of them of Oreo cookies. The scientists claim that there are approximately 3000 valid nudibranch species, but this one is the most amazing.

9. Leafy Sea Dragon

The leafy sea dragon habitat is in southern Australian waters, or Wilson's Promontory in Victoria, to be exact. Its camouflage is intriguing since it appears that it moves through the water like a piece of floating seaweed, maintaining this illusion when swimming. Furthermore, it can also adjust color to adapt to an environment. 

One of the many interesting facts about sea dragons is that they don't have any natural predators. However, these creatures are curling up to present possible threats with the row of menacing spines. This fascinating water animal is famous in Australia since the District Council of Yankalilla in South Australia held the biennial Leafy Sea Dragon Festival to celebrate it.

8. Frilled Shark

Frilled Shark is sometimes called a "living fossil" as it has changed so little since prehistoric times. Some fishermen accidentally caught them as bycatch while targeting other species, though no fisheries specifically target frilled sharks. This active predator is a weird, ancient-looking shark that spends much of its time in deep, dark waters in the Atlantic and the Pacific Ocean.

 Its name origin is from the frilly appearance of its gill slits. The impression of seeing them is quite scary as they have a shark-like head and snake-like body, and their mouth is just as terrifying as the jaws of a great white. 

7. Anglerfish

The Anglerfish looks so bizarre, and we don't ever want to have close contact with it. Luckily, their natural habitat is mysterious depths, so we never have to go there. Seriously, the appearance of the Anglerfish is like the worst nightmare. There's a great variety of colors among the Anglerfish since it goes from dark gray to dark brown. Their heads are large, as they can bear gigantic mouths, full of long teeth that look like fangs, angled inward.

On the other hand, this fish became famous as it reached the front page of Time magazine. Well, no wonder they've chosen the Anglerfish, as it's the true representative of the Time's accompanying title "Mysteries of The Deep."

6. Gulper Eel

Gulper eel deserved the place in our list, as it has a freakish appearance. OK, maybe the right adjective isn't freakish - it's horrifying. The scariest thing in their whole look is a largemouth since they're much bigger than the eel's body. The horrific fact is that Gulper eels can open their mouth wide enough to swallow an animal much more massive than them. 

Apart from their frightening teeth, Gulper eels have one more extraordinary feature, which is bioluminescence. They are also famous as the pelican eel, and their look is unique among the deep-sea creatures.

5. Halitrephes Massi Jellyfish

The magnificent Halitrephes Maasi jellyfish lives in the Eastern Pacific Ocean's deep water, and it's infrequent to spot it. Some researchers found it 4,000 feet underwater at the Revillagigedo Archipelago near California, Mexico. 

Halitrephes Maasi jellyfish display a stunning color palette, which is extraordinarily beautiful. Those colors are the result of moving nutrients through the jellyfish's body and reflect light. So, check out the video above the text, as you'll see the rare footage scientists recorded while releasing a jellyfish they've named the "deep-sea firework" because of its lively appearance.

4. Clown Frogfish

The clown frogfish or a warty frogfish is a marine fish that lives in sheltered rocky and coral reefs. Its appearance is quite strange because of an undefined body shape and numerous small, wart-like bumps all over its skin. 

The clown frogfish have giant mouths, which allow them to consume prey of their size. Also, their body color is exceptionally changeable and suitable for their living environment. For example, during coral bleaching events, they can become plain white.

3. Vampire Squid

Vampire Squid is found everywhere in temperate and tropical oceans in extreme depths. So, don't be afraid, you can't just bump into them while enjoying your swimming. Their body length is six inches, and it varies in color from velvety jet-black to pale red, depending on location and lighting conditions. A webbing skin connects its eight arms, each lined with rows of fleshy spines. 

Moreover, if the vampire squid becomes scared, it will dispatch blue bioluminescent mucus to hypnotize predators so it can swim away into darkness. Believe it or not, Vampire Squid has the largest eyes in the animal kingdom at 2.5 cm (1 in) in diameter.

2. Viperfish

Viperfish is another not so pleasant looking water creature as it has long, needle-like teeth and connected lower jaws. Moreover, it uses its fang-like teeth to immobilize prey. Viperfish attack prey after luring them within range with light-producing organs called photophores. This predator takes place in the Guinness Book of World Records since they have the largest teeth relative to head size! 

The interesting fact is that their color varies from green, silver to black. Also, their life span is between 30 to 40 years in the wild, which is quite long. Viperfish stay near lower depths during the day and shallower depths at night, primarily in tropical and mild waters. Also, viperfish is one of the most brutal predators of the deep. 

1. Christmas Tree Worms

Well, aren't the Christmas tree worms one of the most extraordinary-looking water creatures? Christmas tree worms come in various bright colors, as each worm has two brightly colored crowns that protrude from its tube-like body. Most of their bodies are anchored in holes that they turned into live coral, while beautiful colorful peaks are visible.

These lovely looking creatures live everywhere from the Caribbean to the Indo-Pacific, and their length is less than two inches. They are most widely recognized for their unique shape, beauty, and color.

So, as we already mentioned, the Earth's oceans contain an incredible diversity of marine life. The looks of some of them might strike terror into our minds, but we shouldn't be afraid, as the majority of them live in the deep, dark water. However, there are also so many more creatures that are still waiting to be discovered. We couldn't help but wonder what other water animals are scientists going to find in the future?

How do you feel after exploring our top ten list of some of the strangest looking water creatures? Do you find them scary or fascinating? Feel free to tell us your impressions in the comment section.

Cover photo - YouTube Screenshot