The 15 Most Terrifying Creatures Found In The Amazon River

Voting Rules
Animals that live in and around the Amazon River only. Vote up those you'd least like to encounter.

The Amazon River and its surrounding rainforest are home to some of the most diverse lifeforms on Earth. As one of the longest rivers in the world, the Amazon offers a rich habitat for a wide range of creatures. Some are exquisitely beautiful, while others are undeniably creepy. Many Amazonian species have evolved in ways that make them completely terrifying.

These weird Amazonian animals can be scary for all kinds of reasons. Some look as if they have crawled straight out of a nightmare, such as the Amazonian giant centipede. Others, like the black caiman, are dangerous predators capable of maiming anything they encounter. Then there are the animals that look harmless, but are actually killing machines that should be avoided at all costs. That giant otter may look adorable, but it's as fierce as any sharp-toothed carnivore.

Wondering what animals live in the Amazon? The answers may spook you. Animals wreak havoc all over the globe, but those unique to the Amazon River are especially scary. Check out the Amazon's most fascinating and downright alarming animals. And when you've scared yourself straight, check out our guide on how to survive in the Amazon rainforest, if you ever get lost there.

Photo: JJ Harrison / Wikimedia Commons / CC BY-SA 3.0

  • 1
    10,970 VOTES

    Tyrant King Leeches

    Tyrant King Leeches
    Photo: Public Library of Science / Wikimedia Commons / CC BY 2.5

    The tyrant king leech may only be three inches long, but it's plenty terrifying. It uses its huge teeth to saw into flesh to create holes for it to feed. Worse yet, it seems to intentionally aim for mammals' orifices, including the eyes, genitalia, and rectum.

    Once inside its prey's body, the leech can survive and feed for weeks.

    10,970 votes
  • 2
    11,029 VOTES

    Amazonian Giant Centipedes

    Amazonian Giant Centipedes
    Photo: Katka Nemčoková / Wikimedia Commons / CC BY-SA 3.0

    The Amazonian giant centipede is one of the largest insects, which directly correlates to its creepy factor: an adult giant centipede can measure up to a foot long. This gargantuan critter can be found scurrying around the forest floor near the Amazon River, where it hunts lizards, amphibians, and small mammals living near the water.

    Besides its nightmare-inducing size, it can also inject venom into its victims using sharp claws on its head.

    11,029 votes
  • 3
    12,152 VOTES
    Green Anacondas
    Photo: Daniel10ortegaven / Wikimedia Commons / CC BY-SA 3.0

    Green anacondas live throughout South America. They primarily reside in swamps, marshes, and rivers; this makes the Amazon the ideal home for them. These snakes are gigantic: they can reach up to 30 feet in length and weigh an amazing 550 pounds. 

    These anacondas don't pose much of a threat on land; they're too heavy and cumbersome to have the ability to move quickly. When they are in water, however, it's a completely different story. They can move with devastating speed, and special openings on the very top of their heads allow them to lie almost completely submerged in water. Once they locate and ambush their prey, these anacondas use their immense size and deadly strength to constrict a victim. Anacondas' meals aren't small, either - they've been known to take down jaguars.

    12,152 votes
  • 4
    8,413 VOTES


    Video: YouTube

    The candiru is a type of parasitic fish that lives in the basins of the Amazon River. It's small, typically just a few millimeters in length. What makes it so frightening is the way it feeds. It inserts itself into the gills of a much larger fish, then digs in.

    This shouldn't concern you - except for the story about candirus tending to insert themselves in swimmers' bodily orifices. There's only one documented case of this happening, but it's the stuff of nightmares nonetheless.

    8,413 votes
  • 5
    8,898 VOTES
    Black Caimans
    Photo: Stan Shebs / Wikimedia Commons / CC BY-SA 3.0

    Capable of growing up to 20 feet in length, the black caiman is one of the deadliest animals to call the Amazon River home. The dark coloring of its hide provides perfect camouflage for its nighttime hunts, allowing it to ambush unsuspecting prey in the water.

    It strikes terror into local human populations, too, thanks to its aggressive nature. Black caimans have been known to attack people who live or work on the riverbanks.

    8,898 votes
  • 6
    9,012 VOTES

    Yes, there are sharks in the Amazon River. The bull shark has been found up to 2,500 miles up the river; it makes its way in from Lake Nicaragua. It's one of the most aggressive sharks in existence, and its love of shallow water makes it a hazard for anyone taking a dip.

    If that isn't scary enough, it can also grow to be 11 feet long.

    9,012 votes