These far-out animals fascinate and amuse scientists

Welcome to the wild side of the natural world. We've got crazy squids, ancient tortoises, sea "socks" and a tarantula named after a country-music legend. From the fascinating to the funny, these are some of our favorite critters known to science.

A lot of secrets lurk below the surface of the ocean, but scientists shed some light on an elusive species of seadragon when they captured the first known footage of it in the wild in 2016. The ruby seadragon has a prehensile tail and lacks the leafy appendages of its relatives. These rare sea creatures live in deep waters off the coast of Western Australia.

First published August 17, 2016.
Update, April 17, 2017:Added more far-out creatures.

Biologist Peter Ward spotted this rare species of nautilus near Papua New Guinea in 2015. He last spotted an Allonautilus scrobiculatus three decades before that. These sea creatures are sometimes called "living fossils" since they've been kicking around the planet for around 500 million years.

This video still might not look like much, but it shows a very rare peek at the elusive True's beaked whale. The image comes from the first underwater video ever recorded of the whales. Researchers released the video in early 2017. It shows a group of three whales swimming through the water.

Researchers in Brazil were so thrilled to discover a tarantula chowing down on a snake in the wild, they wrote a paper about it, which they published in late 2016. There's very little documentation of snake snacks by tarantulas, so scientists were delighted to witness the unusual event. Normally, tarantulas eat other bugs or the occasional lizard or rodent.

The research vessel Nautilus spotted an adorable googly-eyed purple squid in August 2016 while filming the sea floor off the coast of California. Technically, it's a rossia pacifica, but it's also known as a "stubby squid." The cute creature became a minor internet celebrity thanks to its unreal looks.

The Nautilus seems to be building up a history with strange purple objects found under the ocean surface. In July, team members shared a video of a strange purple orb discovered in the Channel Islands off the coast of California in mid-2016. Researchers captured the odd object and currently think it might be a soft-bodied marine creature called a pleurobranch. Further research will determine if it's a new species.

In 2016, scientists figured out how to determine the age of mysterious Greenland sharks using radiocarbon dating of their eye lenses. They discovered these remarkable animals have a lifespan of around 272 years. The oldest shark studied was likely closer to 400 years old, setting a record for vertebrate longevity.

Jonathan the Seychelles Giant Tortoise is about 184 years old, but he just had his very first human-powered bath in March 2016. The big fella lives on St. Helena, an island in the Atlantic Ocean that once hosted Napoleon Bonaparte. A veterinarian gave Jonathan a well-deserved soapy scrubbing.

Meet Wisdom. She's around 65 years old and she just hatched a new baby chick early in 2016. The US Fish and Wildlife Service says she's the world's oldest known banded wild bird. She lives in Hawaii and continues to impress researchers with her longevity.

This looks like someone dropped a sock onto the ocean floor, but it's actually a worm-like creature. These rare beasties are found in deep-sea environments and have no brains, eyes or gills. One of the species is even named Xenoturbella churro since it resembles the fried treat.

At first glance, you might not notice much resemblance between this beetle and the furry hero Chewbacca from Star Wars. Scientists, however, realized how hairy the little critter is and named it Trigonopterus chewbacca in tribute to the Wookiee.

UFOs are usually found up in the sky, but a team of scientists found this particular strange object in the South Pacific. In 2015, researchers were thrilled to discover the hawksbill sea turtle is biofluorescent, which lends it this colorful glowing appearance in the right kind of light. The turtle is endangered and more study will need to be done before scientists fully understand why the reptile is biofluorescent.

If you're into watery horror flicks like "Jaws," "Lake Placid" and "Sharknado," then you'll appreciate this very creepy fish pulled from a New Jersey lake in 2015. The fish is not native to that area, but what's especially haunting are its chompers, which look human-like. The finned fiend was identified as a Pacu, a fish found in South America.

This is a great white shark. They're big and perhaps a little scary thanks to "Jaws," but they're not that unusual. What's strange about this particular great white is that it's napping on video. Discovery channel captured the footage of the underwater behemoth taking a snooze and announced it was "the first-ever footage of a great white shark napping." This is the sort of thing ocean explorers live for. Discovery revealed the video just in time for its special Shark Week programming in 2016.

Photographer Tim Samuel took this extraordinary image while snorkeling off the coast of Australia in 2016. A fish is caught inside a jellyfish. Samuel made the decision not to try to free the fish, but rather to let nature runs its course.

This is a tarantula. It's not a Goliath birdeater, a redknee or a rose-haired tarantula. It's a species named "A. johnnycashi" for the country singer Johnny Cash. It was found near Folsom State Prison, made famous in the Cash song "Folsom Prison Blues." It also wears black, just like Cash. It's a fitting tribute for a legendary musician.

A new species of pistol shrimp discovered near Panama earned the rocking name Synalpheus pinkfloydi as a tribute to rock band Pink Floyd. It helps that the shrimp has a screaming pink claw that it uses to make a sound so loud it can stun or kill a small fish. The researchers revealed the name in a paper published in April 2017.

Alien enthusiasts spotted what looked like a fish on Mars earlier in 2016. It's really just a fish-shaped rock, but it was seen in an image sent back by NASA's Curiosity rover. This doesn't qualify as an actual animal, but it no doubt gave some scientists a good chuckle.