10. Axolotl

It’s a freakish insect! It’s a human-looking fish! The axolotl’s bizarre appearance leaves many people asking, “Is it real?” The answer is yes … at least for now. The axolotl, which is native only to a couple of increasingly polluted lakes in Mexico, is listed by the International Union for Conservation of Nature as a Critically Endangered species. The larvae of this salamander never fully go through metamorphosis, leaving the adults stuck with gills and an aquatic lifestyle. Given their appealing appearance, the axolotl has become a popular pet fish.
9. Viperfish

This 12-inch, fierce-looking fish scours the deepest sea zones, down some 9,000 feet in temperate and tropical waters, where it lures prey with a lighted appendage it can flash on and off like a beacon. Once dinner is spotted, the viperfish races at its victim and impales it. Bon appétit. The velocity of the impalement is acute enough that the viperfish has a built-in shock absorber in its first vertebra. The viperfish’s teeth are so long they don’t even fit in its mouth, but rather curl around toward it eyes.
8. Goblin Shark

Despite its interesting name, the goblin shark appears pretty boring — at least until it opens its mouth. Then you get to see the real weirdness of the beast when its set of protrusible jaws blast out from its maw, like something from the Alien movie series. Because the goblin shark lurks in the deeper waters of the Atlantic and Pacific, you don’t have much chance of running into this creature … unless you happen to be a deep-sea crab, squid or fish slated for its dinner. By the way, the IUCN reports that the jaws of this strange fish have become a popular item with collectors in the United States, with some goblin shark jaws fetching several thousand dollars.
7. Hellbender

The name alone merits the hellbender a place on the list, and this aquatic salamander’s fabulous features just keep getting better from there. For starters, the slimy, slinky thing can grow to lengths of more than 2 feet long, making it one of the largest salamanders in the world. Mainly found in Eastern U.S. mountain brooks and streams, the creature is often sadly misunderstood. The hellbender does not gobble up all the fish to leave waterways barren. Nor are they venomous, although you probably don’t want rub your eyes after touching one, due to the slightly toxic secretions that ooze from its skin.
6. Humpback Angler Fish

The humpback anglerfish enjoyed its 15 minutes of fame in the movie “Finding Nemo,” although finding one in the wild would require a diving vehicle, as they live up to a mile beneath the surface of the Atlantic and Antarctic oceans. These angry-looking, giant-jawed creatures attract prey with a bioluminescent stalk that hangs above the females’ heads. Males are smaller and lack a lantern. Since they’d probably starve to death in the deep-sea dark, their main goal in life is to attach themselves to the female, suck the female’s blood, and then leave a deposit of sperm to fertilize the female’s eggs. It’s unclear if similar human relationships are a case of life imitating fish or fish imitating life.
5. Longhorn Cowfish

With its boxy body and cow-like horns, the longhorn cowfish gets big points for adorability. Unless, of course, you try to eat it. Then this Indo-Pacific-region fish can be deadly. Its skin oozes toxic mucus secretions that would make any potential hunter think twice about having it for dinner. These creatures, which can grow up to 20 inches long, mainly hover around reefs minding their own business, and eat a variety of sea life. Tick them off, however, and be ready to fend off the toxic mucus.
4. Leafy Sea Dragon

If you happen to spot a leafy sea dragon, consider yourself fortunate indeed. These Australia-area creatures are masters of camouflage, outfitted with green and brownish filaments that look like, well, leaves. Their leafy limb-like sprouts serve no other purpose than to make the critters mimic a small mass of floating seaweed, and they generally meet their goal. South Australia is so enamored with the leafy sea dragons that it made the “leafies” the state’s marine emblem.
3. Narwhal

The most spectacular feature of these whales is their tusk, which is used to establish order in the narwhal hierarchy. Size does matter. This Arctic beast may have been the basis for the origins of the unicorn myth and they have appeared in classic literature such as Moby Dick and Twenty Thousand Leagues Under the Sea. The narwhal is in danger of becoming somewhat mythical itself thanks to climate changes that are pushing it toward extinction.
2. Candiru

The candiru can do horrible things, which makes it one of the most feared fish in the entire Amazon region. A nearly transparent parasitic catfish, one of the horrible things it can do is bore its way into an animal’s orifices, where it thrives on the host’s blood. If it cannot find an entrance, certain types of candiru make their own by biting out an opening that ends up resembling a bullet hole. It's commonly found inside larger Amazonian catfish, but on occasion, candiru feast on humans; according to the Animal Planet website, human corpses have been found in the Amazon basin with more than a hundred candiru feeding inside.
Although natives have told legends for centuries of tiny candiru swimming up the urinary tracts of men and women as they swim in the Amazon, these tales had been discounted … until 1997. In a well-documented case, a 23-year-old man went to the hospital complaining of terrible pain and difficulty urinating. A surgeon removed a dead candiru from the man’s urethra. The man claimed he had been urinating in the Amazon several days earlier when the fish swam up his urine stream. However, an American scientist who studied the evidence cast some doubt on the tale.
1. Blobfish

The blob fish merits the No. 1 slot on the list for several reasons. Perhaps the primary one is to just give the poor creature a break. This Australia-area fish is certainly one of the oddest-looking creatures on the planet. With a large, bulbous protrusion on its face and a seemingly permanent frown, the blobfish looks a lot like the bald and barefoot cartoon character Ziggy (without the feet, of course). Another sad fact about this fish is its progression toward extinction. Although it is inedible, the blobfish is frequently caught in trawling nets intended for lobsters and crabs.
