- [Narrator] For centuries, humans have gazed at the stars, wondering what life could
lie beyond the atmosphere. But even here on Earth, some
creatures are so strange, unique or downright terrifying, that they'd look more at home on Mars. From cute little critters
with astounding abilities, to blood-curdling monsters
at the bottom of the ocean, let's check out some creatures that are completely out of this world. (upbeat music) Walking plants, the Leaf Sheep is a sea-slug
with a punk-rock haircut, an impossibly cute face and a space-age power
that'll blow your mind. This plant-type Pokemon-like-creature
spends its time, crawling around the ocean, grazing on fields of algae. Only, when it chomps down on the greenery, it also absorbs their chlorophyll, a component that allows
plants to photosynthesize. Instead of wool, the sea sheep's back is covered in leaf-like
appendages called Cerata, and they work just like the real-thing. Storing chlorophyll, they allow nutrients and
energy to be absorbed from sunlight like a moving solar panel, turning the Sea Sheep into
a plant-animal hybrid. When I sunbathe, all I get is sunburn. The Sea Sheep's rare
ability to photosynthesize, makes it an incredibly
unusual cross between plant and animal; and coupled with its appearance, it makes it the type of creature that you'd to expect to find
on a whole other planet. (upbeat music) Telescopefish, believe it or not, this isn't a photo of
me on a Monday morning. This is a Telescope fish, the deep sea's scariest predator. The fish looks like a mad-alien-scientist and you can just imagine him
jetting across the solar system in a UFO. The Telescope fish gets its
name from the tubular eyes that stick out if its head, their unique shape giving
the fish powerful vision that's hypersensitive to light. Despite swimming up to 10,000 feet deep, the 7-inch-long Telescopefish, can detect small amounts of light coming from the ocean's surface. As a result, the telescope fish hunts by floating vertically through
the ocean and looking up, allowing it to see the
silhouettes of its prey as they swim above it. If the hunt is successful, the telescope fish's unique jaw, allows it to swallow prey
larger than its entire body, thanks to its huge, expandable stomach. While this alien-looking fish's eyes, might not quite be bigger than its belly, they're certainly pretty close. (upbeat music) The Antarctic Scale Worm, look at this golden creature, floating through the water
like a designer purse. Its scales look like soft, 24 carat gold and it's a reminder of how
beautiful life on Earth, can really be, that is, until you get
within biting distance. Truly horrifying. This is the Antarctic Scale Worm, and the part that looks
like the creature's head is actually a retractable throat, that's usually folded into its body. The Scale Worm's hunting tactics, are straight out of a Sci-fi horror flick. A curious little animal swims
up to a beautiful golden alien to check it out, but
when it gets too close, the Scale Worm's throat
bursts towards them, snapping them up with
its razor-sharp teeth. The Scale Worm is nature's mullet; party at the back, evil
devil-spawn at the front. Thankfully, the worms are
only found in Antarctic waters and they're pretty rare, meaning that we don't know much, about their breeding
habits or what they eat. My guess? Souls and puppies. Aliens from the depths. A long time ago, in a galaxy
known as the Milky Way, a cave near Mangalia, Romania, was sealed up by the
shifting of Earth's crust, trapping a little society
of animals together for 5.5 million years. In 1986, a team of construction workers, accidentally drilled into this place, now known as Movile cave, discovering a small space
filled with deadly toxic gases, intense heat and 33 completely
new species of animals. The creatures had made themselves at home in a pretty unhomely place, evolving to survive the
cave's extreme conditions, over millions of years. This means that they evolved in a totally different world
to other life on earth. In Movile cave, some of the creatures are transparent and most of them are completely blind, their eyes disappearing
over millions of years as they developed longer antennae and arms to feel their way around
in the pitch-black. Movile is largely filled
with sulfuric water, but most of these bugs thrive
in little pockets of air that appear in the
cave's walls and ceiling. The air in these pockets is composed of usually-deadly
amounts of carbon dioxide, methane, hydrogen sulfide and ammonia, and is only 10% oxygen; half the oxygen level on Earth's surface. Yet, the tough little bugs have evolved to survive these conditions; able to swim, crawl and hop around despite
the cave's toxic air. In fact, the sulfur and
methane present in the cave is central to the food chain, those chemicals are fed
upon by bacteria and fungi, which in turn feed the
cave's herbivorous occupants; who then feed the cave's predators. Some scientists believe Movile
cave might unlock the secrets of alien life elsewhere in the universe, allowing us to understand
how creatures can thrive in places usually be
considered inhospitable. Thermal imaging has shown that there are cave networks
on Saturn's moon Titan, for example, and if parts of these caves are cut off and protected from the harsh conditions on the moon's surface, alien life might've been able to evolve. I always thought aliens would
be hi-tech and futuristic, not literal cavemen, but I'll take what I can get. The Blob, when I was a kid, all my teachers used to call me Brainless, but maybe that isn't such a bad thing. Case in point, Physarum Polycephalum, a type of slime mold, which despite having
no eyes, ears or brain, exhibits the possession of memory, solves basic math problems, and navigates mazes. Pretty impressive for
a brainless creature, take that, Mrs. Murphy. In one experiment, Japanese scientists at
Hokkaido University, recreated a map of Japan in a Petri dish, placing flakes of food
down in certain positions to represent Tokyo and
its surrounding cities. Within hours of being placed on the dish, the slime mold composed
of thousands of tiny, amoeba-like organisms working
together as a single unit, had sent tendrils of
slime towards the food, almost perfectly recreating
Japan's trainline-routes in the process. Working out the most efficient way to connect these cities took
human engineers over a century, but the slime mold solved the
problem in just over a day. The fact that slime
mold can solve problems and store basic information
without neurons or a brain has stumped scientists around the world, proving how little we know
about life on our own planet. If we meet aliens one day, they may not necessarily be humanoids with giant brains, they could have a totally
alien type of intelligence that we can't even imagine, just like slime molds. With that in mind, I'll be a little less bugged out if that moldy lettuce in
the back of my fridge, ever starts talking to me. Pyura Chilensis, if aliens really live on earth, then they've been doing a pretty good job of disguising themselves and no creature is better disguised, than the Pyura Chilensis. At a glance, the Pyura looks just like a big rock, until you cut it open, revealing its fleshy, red insides. Images of Pyuras look totally alien, and the idea of a rock with organs is absolutely sci-fi horror territory. It's one of the only living rocks that isn't called Dwayne, but unfortunately, the Pyura
is all rock and no roll, belonging to a class of immobile
animals called sea-squirts. The Pyura's outer layer
is known as its tunic, a cellulose-like material
that forms an exoskeleton, protecting the creature as it
attaches to a rock and feeds, sucking in seawater and
filtering out the algae and microorganisms to eat for dinner. But if Pyura Chilensis
are undercover aliens, they're not doing a great job. In Chile, their insides are eaten as a delicacy, and some people even use the
rock's meat as an aphrodisiac. Now, that's a sentence I
never thought I'd have to say. Space Bears, everybody loves a superhero, and our next creature is an animal with some real-life superpowers. The Tardigrade might not
wear a cape and spandex, but these little creatures
are practically invincible. At 0.04 inches long, these creatures might not seem so tough, but they can survive temperatures, ranging from 300 degrees
Fahrenheit to minus 457 degrees. If a tardigrade is completely dehydrated, it'll shrivel into a tiny ball, carrying out a process
called vitrification that temporarily turns the
fluid in its cells into glass. Tardigrades have been known
to survive in this state for over 10 years and if they're reintroduce
to water decades later, they'll spring back to life
like a microscopic zombie, their cells reverting back to normal. All that's pretty cool, but what makes them so alien? Well, they can survive in space. In 2007, a Russian space mission, took some dehydrated Tardigrades
up into Earth's orbit and exposed them to the
hard vacuum of outer space for 10 days. The tardigrades were
faced with temperatures of minus 455 degrees Fahrenheit and a vacuum that would
kill a human within seconds. Despite all this, within an hour of being
brought back to Earth and rehydrated, the tardigrades were scrambling around, like nothing had happened, making them the only
known creatures capable of surviving the vacuum of space. This wasn't a one off. In 2019, an unmanned Israeli spacecraft
carrying tardigrades, crash landed on the moon
after a total failure of its main engine. Some experiments have
shown that the Tardigrades, probably wouldn't have
survived the impact, but the co-founder of the
Israeli Space Organization was adamant that they're still alive, meaning that a little group of moon bears, might be crawling around
up there as we speak. If that's the case, then these tardigrades really are aliens, becoming the first known creatures to live off of the planet. Ancient Aliens, believe it or not, these things aren't cheap
props from a sci-fi film. These are Crinoid fossils, an ancient creature that swam around, 300 million years before the dinosaurs. Their bulbous heads and curling
tentacles are terrifying to look at and the fossils
have been used as inspiration for creatures in movies, like the Sentinels in the "Matrix" and the facehuggers in "Alien." Crinoid fossils are so old, scientists aren't even certain what the creatures evolved from. Judging by their appearance, I'd like to say the
answer lies in the stars and their ancestors looked
something like this. But of course, that's purely
speculation on my part. The descendants of crinoids, however, are still swimming around today, showing us what ancient crinoids, would have actually looked like and how they moved around the ocean. If these feathery friends, make the crinoid fossils seem less scary, just remember that the largest
crinoid fossil ever found, was 130 feet long. And I thought the current
oceans were scary enough. E.T. the Extinct Terrestrial, while the creatures living on Earth today, can be pretty strange, as we just saw with the ancient crinoids, they're nothing compared to the creatures of the ancient past. The seas of the past were occupied by truly alien-looking creatures, like this Terataspis Trilobite, gigantic bugs with spine-covered backs, snaking antennae and 27-inch-long bodies. Fortunately, the creature in
this image is just a model, but these monsters really did exist, crawling along the ocean
floor million-years-ago. In 2016 NASA released a
new set of images from Mars and conspiracy theorists
spotted a couple of rocks in the background that they theorized
were Trilobite fossils. The blurry evidence is
pretty unconvincing, but it shows that when you find a creature as freaky as a Terataspis Trilobite, it sends some people's minds
heading right for the stars. Even stranger than the
trilobite is the Hallucigenia, an insane ancient sea-worm, sporting neck-tentacles, spiky spines and a ton of teeth in
all the wrong places. But don't freak out too much, because these little guys
were only half-an-inch long. When scientists first
found Hallucigenia fossils in the 1970's, they couldn't even work out, which way up the Hallucigenia walked or where its face was. After prodding and poking
at the fossils for decades, they started to understand the wacky world of the Hallucigenia, leading to animations and drawings that show just how alien
this creature really was. As for its neck-tacles? Scientists still aren't
sure what they did, but I reckon they could
be used to bust out, some pretty sweet dance moves. Scientists might've cracked
the code on the Hallucigenia, but some fossils are so strange that they still remain a mystery. Take the Tully Monster, discovered by amateur fossil
collector Francis Tully for example. Despite more than 100
Tully Monster fossils, being uncovered since 1958, scientists still don't
know whether the creature was a type of worm, mollusk, eel or fish. We do know that it was a sea creature, it lived 300 million years ago and it was really, really freaky. Its eyes were attached to stalks, jutting out the top of
its 14-inch-long body, and its mouth sat at the end
of a long stretching neck, ready to grab at its prey. Nobody knows for sure
what it evolved from, or evolved into, and the mystery surrounding
the Tully Monster has led to a wave of conspiracy theories. Some people think it's an alien creature, others think it's an ancestor
of the Loch Ness Monster. I'm not convinced this thing
isn't an alien jet ski, left over from intergalactic spring break, half a billion years ago. Let me know your theories
in the comments below. Ink-Redible Octopi, for some people, the idea of aliens currently
living on Earth is ridiculous, but that doesn't necessarily mean that they haven't ever visited the planet. Get ready to put your tin-foil hats on, because according to a
team of 33 researchers, Octopi are aliens that
were brought to Earth by meteors. In a paper published
in the science journal, "Progress in Biophysics
and Molecular Biology," a group of scientists argue
that 540 million years ago, the Earth was struck by a comet, carrying either fertilized
octopus eggs from another world or an alien virus that infected
a group of primitive squid, causing them to mutate and evolve into the modern octopus. These claims might seem insane, until you look at all
the tenta-cool things that octopi can do. They can camouflage themselves, spray ink, fit through tiny
spaces and regrow lost limbs. The ocean is octo-pied by
289 species of octopus, and some of them are super intelligent, known to solve complex puzzles and unscrew the lids on
containers to access food. The scientists behind the paper state that these adaptations
seemingly evolved very suddenly, and octopus' ancestors show no signs of having any of these traits. So, maybe an asteroid-riding
alien squid monster is responsible for Octopi
as well as Crinoids? Those creepy fellows
really got around, if so. Unfortunately, the controversial paper
received very few supporters in the wider scientific community, given that it was almost purely theory, with no real evidence to support the
extraterrestrial Octopi claims. That being said, considering
Octopi eggs look like this, if anything, I'd need a
scientific paper to convince me that that isn't an alien. Mouth Invaders, with all the abductions, invasions and body-replacing imposters, the extra-terrestrials in pop culture don't always come in peace. Luckily, these terrifying
types of monsters, are just works of science fiction, right? Nope. Meet the Cymothia Exigua, a real-life body invader, also known as the tongue-eating louse. But the louse doesn't just eat tongues, it's way worse than that. The louse preys on fish, entering their bodies through the gills and severing the blood
supply to their tongues, making them rot and fall off. The parasite then replaces the tongue, living inside the fish's mouth and acting as a fully
functional, living prosthetic. This allows the fish to go on living, swimming around and looking for food, while the louse drinks its blood or mucus. When their fish dies, these little squatters just crawl out and search the ocean for
a new host to live in. I'll bet their fish of
choice is a brand-new tuna; eight bedrooms, four bathrooms and a hot tub in the backyard. Comb Jellies, when you travel down to
the bottom of the ocean, it starts to look more like
deep-space than the deep-sea. With creatures like the
sharpear enope squid, which lives 3,000 feet below the waves, it's not hard to see what I mean. But some of the most mind-blowing
deep-sea creatures of all, are Comb Jellies; mysterious invertebrates that live up to 23,000
feet below the surface. There are over 100 known
species of comb jelly and each one is just as alien as the next. They can be dark red,
translucent or a dazzling blue, but almost all of them are covered in what look like flashing
multicolored lights, like UFO's or gaming keyboards. Comb Jellies have been swimming around for at least 500 million years, but they have space-age abilities. A deep-sea camera caught
this footage for example, over 3,000 feet below the Indian Ocean. This symmetrical shape might
look like a CGI spaceship, but it's actually an incredibly rare type of black-pigmented Comb Jelly with the ability to change
its form in seconds, morphing into a ghostly figure
with arrays of colored lights that appear to twinkle. This creature's ability to shape-shift is unique amongst Comb Jellies and scientists theorize that
its uses the ability to feed, catching prey in its blanket-like body or possibly to scare off predators. Despite its appearance, this comb jelly isn't actually covered in a set of rainbow LEDs. Almost all Comb Jellies are
covered in microscopic hairs, called cilia that they use
to paddle through the water. As light passes through the cilia, they act like prisms, breaking the light apart to
separate wavelengths of color, giving the appearance of
individual, colored lights. As incredible as it all looks underwater, if a Comb Jelly ever ends up on dry land, they lose their mysterious appearance, due to the much lower pressure, compared to what they're
used to in the deep sea, looking more like a big
puddle of hand sanitizer. But at least that puddle of goo, seems less likely to want to
probe you in its spaceship. The Mantis Shrimp, what do you get when you
cross the eyes of an alien, the face of a prawn and
the fists of Mike Tyson? The Mantis Shrimp. Whoops, no. This Mantis Shrimp. There we go. Humans only have three color
receptors in their eyes, whereas Mantis Shrimp have 16, meaning that they can differentiate colors at a level we can't even imagine. Their eyes are by far the most complex visual structure
ever discovered on earth, even able to detect UV
light and polarized light. With the ability to see forms
of light that are invisible to the human eye, mantis shrimp present an
intriguing possibility. That being, there could
be alien life out there or even on our planet that exists within frequencies of light or even types of matter, that our limited senses are
totally unable to perceive. There could even be an invisible alien, sat next to you right now. If that idea scares you, it might be time to learn from the Mantis Shrimp's
other amazing talent. Despite being just 6 inches long, they can use their club-like claws to hit their prey with the same velocity as a 22 caliber rifle, firing off punches at
over 50 miles per hour. Fishermen affectionately call
Mantis Shrimp, Thumb-Splitters and the creature's uppercut is so powerful that it vaporizes the water around it, resulting in super-heated bubbles, approaching the temperature
of the surface of the sun. So, to protect against invisible aliens, float like a butterfly, sting like a Mantis Shrimp. Mantids, let's keep the Mantis train rolling, moving on to the Mantis Shrimp's namesake, the Praying Mantis. Back in the 90s, there were admittedly questionable reports of people being abducted by Mantis-Aliens; seven foot tall Mantids
that could shape-shift, using alien technology in their
UFO's to appear more human and fit into their surroundings. Of course, seeing as it was the 90s, all they really needed
to fit in was a tracksuit and a pair of dungarees. But similarly, in parts
of Southern Africa, the San people tell ancient
myths about a trickster god, called Iaggen, a praying
Mantis that could shapeshift, into ordinary San people
and mimic other animals. A small group of conspiracy
theorists believe that these myths are real sightings of the same Mantis-Aliens, theorizing that these
creatures have preyed on humans for centuries. Obviously, the idea that
Mantids belong to a race of shape-shifting aliens is pretty insane, but the origins of the stories, become slightly more understandable when you look at some of
the vert real mantids, living on Earth. Take the Orchid Mantis, a bright pink critter
that mimics a flower, luring plant-eating bugs
and pollinators towards it, before striking. The Orchid Mantis might be too pretty to be an evil alien overlord, but take a look at the Empusa Fasciata, a species that has tall,
towering crown extensions, that make them look
extra, extra-terrestrial. Its thin green body and purple appendages, look just like a flowering plant and it's easy to see how ancient cultures and religions could worship these masters of disguise as shape-shifters. To most of us, these mantids prove the
wonders of evolution, but to the conspiracy theorists, they're just proof that the Mantis-Aliens, have already infiltrated Earth, disguising their little
cousins as plants and flowers to spy on us, gathering intel on the human race, until it's time to strike. The Noodle Hop-Hop, believe it or not, this next creature isn't
an alien from "Star Wars," a rat from a parallel universe or the winner of a
re-design the mouse contest. This is a Jerboa, a real creature that's 60% tail, forty percent leg and 100% ridiculous. The Kazakh people of Northern
China call the Jerboa, Noodle Hop-hop and it's easy to see why. It might look like a potato on stilts, but the Jerboa's long springy legs, allow them to flee predators at up to 15 miles per hour, and evasively leap 10 feet into the air with a bit of practice. If they can jump that high on Earth, imagine how high they
could get in zero gravity. Bigfin Squid, before we started
looking out to the stars, people were terrified of the mysteries that lay underneath the ocean. Tales of sea monsters have
occupied humanity for centuries, and in 2007, a team of scientists captured some footage of a real-life example. This monster is a Bigfin Squid, swimming 7,800 feet
below the Gulf of Mexico. Its tentacles are 26 feet long, held out to the squid's sides, before dropping at right-angles
down to the depths below, swinging around like
demonic puppet strings. Scientists believe that
the squid might drag these tentacles across the depths, grabbing any edible
organisms that it encounters and pulling them up to its jaws. It's just like the claw
machine at the arcade, although something tells me that the Bigfin rarely drops its prey. Sightings of the creature
are incredibly rare, but when one occasionally
gets spotted by a submarine at the bottom of the ocean, surrounded by particles
that shimmer like stars, the Bigfin squid really does
look like an alien monster, floating through the cosmos. So, which of these alien creatures, do you think is most likely
to hail from outer-space? Let me know in the comments
below and thanks for watching. (upbeat music)
