18 of The Most Interesting Rainforest Animals

Written By Jill Taylor

Tropical forests are warm, crowded, and wet habitats close to the equator that are teeming with life of every variety. Although you may be familiar with many of the animals that live there, others can be weirdly surprising. Here, we delve into the jungles of our world and reveal 18 of the strangest animals that inhabit them.

Sloth (Folivora spp.)

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These slow-moving and unusual-looking mammals exist on a low-energy diet of tough leaves in South American rainforests. The WWF states they only sleep for 8–10 hours a day but spend much of their waking time in the slow lane—they’re often covered with green algae that they use as camouflage and only descend to the forest floor to defecate once a week!

Okapi (Okapia johnstoni)

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Treehugger claims these stripy relatives of the giraffe live in only one country in Africa—the Congo. They are herbivorous and shy, preferring dense jungle habitats and avoiding humans—indeed, they are one of the most recently discovered large mammal species. Oh, and guess what? The Okapi’s tongue is so long that it can clean its own ears and eyes!

Proboscis Monkey (Nasalis larvatus)

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This comical-looking monkey is named for the bulbous, drooping nose that all males of the species develop—thought to enhance the vocalizations they make to attract mates. World Land Trust reports that they are native to the mangrove forests of Borneo and form flexible social groups of one male with a harem of females. Unusually for primates, they can swim and eat unripe fruit!

Cassowary (Casuarius spp.)

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Native to the rainforests of Australia and New Guinea, the Library of Congress names cassowaries as the world’s most dangerous bird! They are large and brightly colored, with blue heads and an unusual helmet-like casque on their heads. Despite their ‘flashy’ appearance, they are naturally shy and typically only kill humans when kept in captivity.

Leafcutter Ants (Atta spp.)

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These ants are found throughout South and Central America’s rainforests and have a complex social structure. They also have a remarkable relationship with a fungus, which they cultivate and ‘feed’ with the leaves of various plants. McGill University reports that they’re one of the few insect ‘farmers’ known to man and even protect their fungal crop from pests and mold!

Aye-aye (Daubentonia madagascariensis)

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Native to Madagascar, the aye-aye is the world’s largest nocturnal primate and has a bizarre appearance, including rodent-like teeth, huge ears, circular eyes, and an excessively long, thin middle finger. This lemur uses its finger as a tool to tap on tree bark and to help it find and extract insect grubs.

Glass Frogs (Centrolenidae spp.)

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Inhabiting the rainforests of Central and South America, glass frogs are named for the translucent skin on their abdomens, allowing their internal organs to be clearly seen. Viewed from the top, they look green, but peering underneath reveals an educational sight—much akin to an anatomy textbook! Apparently, this adaptation aids with camouflage.

Pangolin (Pholidota spp.)

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Several species of pangolin inhabit jungle habitats in Africa and Asia and have an unusual covering of protective keratin scales over their entire bodies. These act as armor and provide protection from predators. According to National Geographic, this unique-looking rainforest dweller is the most trafficked non-human animal in the world and is critically endangered.

Tarsier (Tarsiidae spp.)

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Another strange-looking primate, the tarsier is found in the rainforests of Southeast Asia and has huge eyes—each eyeball is the same size as its brain! These nocturnal predators have a unique hunting method, which involves leaping at their prey (insects and small animals) and catching them with their hands.

Amazonian Giant Centipede (Scolopendra gigantea)

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Resident to the Amazon rainforest and surrounding countries, this huge invertebrate can exceed 12 inches in length and preys on various animals, including insects, tarantulas, and small vertebrates. iNaturalist states that it uses its venomous claws to subdue its victims and is strong enough to kill snakes, rodents, and even bats!

Harpy Eagle (Harpia harpyja)

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This huge raptor is one of the world’s largest and most powerful predatory birds. Living in the rainforests of Central and South America, the harpy eagle is an apex predator and uses its strong talons and excellent eyesight to snatch mammals (like monkeys and sloths) from tree branches.

Titan Beetle (Titanus giganteus)

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Native to the Amazon rainforest, this is the largest beetle species in the world, with adults reaching lengths of up to 6.5 inches! The Smithsonian Institute reports that their incredibly strong mandibles can snap pencils in half or pierce human flesh. Despite their huge size, they can fly (although not directly from the ground.)

Electric Eel (Electrophorus electricus)

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Found in the Amazon and Orinoco river basins, this unique freshwater fish can generate powerful electric shocks of up to 600 volts to stun prey or in self-defense. It’s not a true eel but a type of knifefish, and even uses electrical currents to navigate its murky environment and communicate with other eels.

Hoatzin (Opisthocomus hoazin)

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This pheasant-sized bird is nicknamed the “stinkbird,” and with good reason! Unusually, it’s entirely herbivorous and searches for plants amid the Amazonian swamps it calls home, fermenting the vegetation in its stomach like a cow! This leads to it having a strong, manure-like odor. As if that wasn’t enough, they also have ‘claws’ on their wings that they use to climb trees.

Pink Dolphin (Inia geoffrensis)

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Also known as the Amazon river dolphin, this rare mammal is one of the few dolphin species to inhabit freshwater. The BBC reveals that it has some unique adaptations, too, like pink skin, extremely flexible necks, and paddle-shaped flippers that can move independently—all useful when navigating the shallow, murky waters they live in.

Kinkajou (Potos flavus)

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The “honey bear” is a small mammal found in rainforests from Mexico to Brazil. It resembles a primate but is actually more closely related to raccoons. They have an amazing, prehensile tail that acts as a fifth limb, aiding them in maintaining balance and reaching good foraging in their tree-top habitat. Although they eat fruit, they are particularly fond of honey!

Candiru Fish (Vandellia cirrhosa)

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Also known as the toothpick fish or vampire fish, this parasitic freshwater catfish is found in the Amazon basin. Adults can grow up to 16 inches in length and are known to parasitize the gills of larger fishes to feed off their blood. There have even been reports of juvenile candiru entering the urethras of men foolish enough to enter their habitat!

Driver Ant (Formicidae spp.)

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According to Britannica, these nomadic African ants are constantly on the move and extremely aggressive. When not in an ‘egg laying’ phase, colonies march over the ground, attacking anything in their path—reptiles, insects, birds, mammals, and even humans!