Uncovering some of the creepiest, freakiest and downright ghastliest monsters in real life.

The world's weirdest and most fascinating underwater creatures, from glowing fish to needle-eating eels and more.

One insect sprays molten-hot acid from its rear; another injects its larvae into living caterpillars, where the young gnaw their way out; the giant centipede roams the caves of Venezuela and hunts for its favorite meal: live bats.

These monsters bite, chew and gnash on anything that gets in their way and their fangs are as varied as they are fearsome - from the weird teeth of the Dracula fish to the deadly fangs of the Gaboon viper and infamous chompers of the Piranha.

Frogs the size of small dogs; plants that swallow entire rodents; the largest crocodile species on earth - capable of consuming an entire antelope.

From hives of naked mole rats, to the burrows of the bizarre aardvark, to zombie creatures that tunnel through decomposing flesh, this is nature's real freak show - underground.

From the bat that pulls fish from the water with giant claws to the bloodsucking vampire bat, we journey through a strange collection of winged beasts that are as bizarre as they are fascinating.

From spiders that can walk on water and even breathe underwater, to ones that can weave glittering webs to catch prey by the dozens, and the mammoth tarantula that eats entire birds for breakfast.

Sir David Attenborough takes viewers deep into the world of bugs. Pioneering macroscopic techniques allow Attenborough to explore in unparalleled detail the intricate, sophisticated behaviors of fascinating creatures and the complexity of the environments they build and inhabit in a world normally hidden from the human eye. Each episode explores a different aspect of the little-known lives of insects, from the deceptive defensive mechanisms harbored by spiders and scorpions to the creation of colonies and how social arrangements develop.

English naturalist Chris Packham explores some of the strangest natural events to be caught on camera in this docuseries. Assisted by scientists and experiments, Packham explores the secrets behind bizarre science, crazy weather and medical marvels. Using footage taken by eyewitnesses and news crews, the host attempts to decipher the truth behind each scene. Some of the incidents under scrutiny are unusual animal friendships, towns under the siege of thousands of flying insects and extraordinary mating calls that have kept people awake at night.

Adventurer/survivalist Bear Grylls hosts and narrates this six-part docuseries, which draws attention to the volatility of Mother Nature and the resilient animals that survive Earth's most extreme habitats. Each hourlong episode characterizes one of the planet's roughest environments -- including jungles, mountains, deserts, oceans, the poles and grasslands -- and how each of its inhabitants acclimate to its turn of events. As Grylls guides viewers through these extreme locations, the incredible ways in which animals have adapted to survive against all odds are celebrated. As well, underscored is a sense of urgency to the effects of climate change.

David Attenborough investigates the evolution of nature's flight in this documentary series. Using 3D macroscopic and high-speed filming techniques, the show captures flying mammals, reptiles and insects, as well as birds from all over the world. Attenborough travels from Scotland to Borneo to find the extraordinary species gracing the skies. Created by the award-winning team behind "Natural History Museum Alive" and "Flying Monsters," this series utilizes the latest technology to delve deeper into the animal kingdom to present the natural world's engineering and aeronautics in action.

Aquatic ecologist Zeb Hogan gets up close and personal with bizarre giants of the water, specimens equally enormous in proportion and odd in appearance. Among other adventures, Hogan investigates flying fish from Asia that are invading America's waterways, and he searches for one of North America's toothiest and most-misunderstood monster fish, the alligator gar. Some of the species Hogan encounters have survived for centuries but now face the threat of extinction, and he presents groundbreaking research undertaken to protect them.

Jeremy Wade is not a fisherman; he's an "extreme angler" in search of the biggest and most dangerous freshwater fish, the kind with a taste for human flesh. This action-adventure series also features Wade illustrating how these river monsters are constructed to kill.

British adventurer and cinematographer Richard Terry travels to faraway jungles and remote islands in search of the truth behind stories of unknown creatures attacking, and killing, humans. In the Amazon rainforest, Terry is on the trail of a huge spider said to be attacking villagers; in southern Mexico, reports of a terrifying creature that attacks locals at night sends Terry into the jungles of Chiapas to investigate; and in the Indonesian archipelago, Terry island hops to expose a giant, blood-thirsty reptile that preys on livestock and humans.

From the frozen tundra in the north to the dry forests of the equator, Sir David Attenborough narrates a compelling view of the planet. "Planet Earth" was the first natural history documentary to be filmed in high definition, and now a decade later improved technology has made it possible to capture further details, from elusive animal behaviors to previously inaccessible remote landscapes. In addition to exploring the wilderness, the series examines urban dwellings, focusing on animals that have adapted to city life.