Animals Wildlife 15 Fascinating Frog Species By Jaymi Heimbuch Writer California Polytechnic State University, San Luis Obispo Jaymi Heimbuch is a writer and photographer specializing in wildlife conservation. She is the author of The Ethiopian Wolf: Hope at the Edge of Extinction. our editorial process Twitter Twitter Jaymi Heimbuch Updated February 08, 2021 ronikurniawan / Getty Images Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species There are a lot of frogs on this planet — 4,740 known species, to be exact, with more still being discovered by scientists on a yearly basis. With all those species comes a lot of diversity and variation; these amphibious creatures have evolved to specialize in their environments in ways even the most creative fiction writers couldn't envision. Species range from the size of a fingernail to over a foot in length, and others have far-fetched adaptations like poisonous skin, the gift of flight, and surviving the cold by simply freezing (and thawing back out when it warms up again). Unfortunately, these specializations can also make frogs sensitive to habitat loss, and they are becoming endangered and facing extinction at a rapid pace. Here are 15 incredible species that showcase the diversity these amphibians possess and the challenges they face. 1 of 15 Diane's Bare-Hearted Glass Frog mlorenzphotography / Getty Images Discovered in 2015, the Diane's bare-hearted glass frog (Hyalinobatrachium dianae) is long in name but small in stature. This inch-long species is one of more than 100 species of glass frogs, unique for their translucent skin, which leaves the internal organs visible. A nocturnal creature, it is native to the rainy foothills of Costa Rica, where it feeds on small insects. Frogs are often seen as indicator species, and this species's discovery is considered a promising sign of forest health in Costa Rica, despite the threat of deforestation worldwide. 2 of 15 Paedophryne amauensis shandor_gor / Getty Images Glass frogs may be small, but they have nothing on the Paedophryne amauensis, which at only 0.3 inches in length isn't just the smallest frog, but the world's smallest vertebrate. This native of Papua New Guinea was discovered in 2009, by researchers who heard its high-pitched call, then scooped leaf litter into a plastic bag to figure out what was making the noise. In addition to its diminutive size, it is unique in that it has no tadpole stage, hatching instead as a miniature of the adult. 3 of 15 Desert Rain Frog Ryanvanhuyssteen / Wikimedia Commons / CC BY-SA 4.0 The Desert Rain Frog (Breviceps macrops) is a rare species found only along a 6.2-mile wide strip of coastline in Namibia and South Africa. It's also one of the rare frogs to go viral, thanks to its squeaky voice. It is nocturnal and buries itself beneath the sand during the day, where it can stay cool and moist, then comes out at night to feed on insects and larvae. Its specialized habit is threatened by human settlement and open-cast diamond mining, and scientists are concerned that the frog's population is declining. 4 of 15 Ornate Horned Frog Studio-Annika / Getty Images The Ornate Horned Frog (Ceratophrys ornata) is also known as the Pacman frog, and for good reason. It has an insatiable appetite packaged in a six-inch body that is half mouth — literally. These frogs are known for their fearless behavior and will prey on anything from to lizards to rodents to other frogs. They have even been found to suffocate on large prey that they chose to consume despite the risk. The species is endemic to Argentina, where its splotchy red and green coloration helps conceal it on the forest floor. 5 of 15 Hairy Frog Paul Starosta / Getty Images The hairy frog (trichobatrachus robustus) is another species with a well-earned nickname. Also known as the horror frog or wolverine frog, it will intentionally break its toe bones when threatened, which then poke through the skin to act like claws. These bones later retract and the damaged tissue heals. It's the only animal researchers know of with such a defense mechanism. The name horror frog is also fitting due to the hairlike growths on the sides of the males called dermal papillae. This growth is thought to help breeding males consume more oxygen, which comes in handy during long periods spent underwater, guarding eggs laid by females. 6 of 15 Vietnamese Mossy Frog davemhuntphotography / Shutterstock The Vietnamese mossy frog (Theloderma corticale) lives in the forests of northern Vietnam, where it spends its days pretending to be a moss-covered rock. With its green and black coloration and bumpy skin covered with spines, it is well suited to the task at hand. It prefers a semiaquatic environment, hunting cockroaches and crickets in caves and streambeds. To ward off predators, which include snakes and tree-dwelling mammals, it can take its disguise one step further by rolling into a ball and playing dead. 7 of 15 Golden Poison Dart Frog The golden poison frog (Phyllobates terribilis) is the most poisonous poison dart frog. Paul Starosta / Getty Images The golden poison dart frog (Phyllobates terribilis) might be small, but it packs a mean punch. Each two-inch frog has enough toxin to kill two bull elephants. How the tiny frogs manage to be so toxic is still a mystery to researchers, but one hypothesis is that it can be traced to poisonous plants eaten by their own insect prey. Frogs raised in captivity never become toxic; only the wild frogs are lethal. It is abundant in its rainforest habitat in coastal Colombia, but the small size of this shrinking forest has put the frog on endangered species lists. 8 of 15 Indian Bullfrog Vivek Parab / Getty Images Not all yellow frogs will kill you — some, like the Indian bullfrog (Hoplobatrachus tigerinus), will just entertain you with their singing skills and vivid colors. For most of the year, these frogs are a dull, olive-green color. However, during mating season, the males turn a Day-Glo yellow with indigo vocal sacs on their throats. With a body about six inches long, this is the largest of the Indian frog species. In the 1990s, people started farming the frogs as a food source. They have also become an invasive introduced species in the Andaman Islands. 9 of 15 Brazilian Horned Frog This aggressive frog matches its surroundings, making it a deadly foe for any passing prey. Dirk Ercken / Shutterstock Like the ornate horned frog, the Brazilian horned frog (Ceratophrys aurita) is an aggressive predator. It grows to an even bigger size, up to eight inches long, and is a "sit and wait" predator, burrowing itself in leaf litter with only its eyes visible, and waiting for prey to pass by. It will attack anything nearby, using its abnormally powerful jaws to go after animals of all sizes, including larger animals that it doesn't consider prey. 10 of 15 Wallace's Flying Frog ronikurniawan / Getty Images The Wallace's flying frog's name gives away its secret. This species found in the jungles of Malaysia and Borneo has the unique ability to fly — or more accurately, deploy a leg-powered parachute. It has long, webbed toes that can flex and spread out to act as tiny wind sails, which it deploys when it feels threatened. To escape danger, it will leap from branches, spreading its feet to glide as far as 50 feet to safety. It spends almost its entire life in trees, venturing to the ground only to mate and lay eggs. 11 of 15 Venezuela Pebble Toad Gérard Vigo / Wikimedia Commons / CC BY-SA 3.0 The Venezuela pebble toad (Oreophrynella nigra) is a small frog (toads are types of frogs that prefer drier climates) that lives in the Guiana Highlands of Venezuela. It has evolved a unique defensive technique that only works on the steep slopes of its mountainous habitat. When threatened, it tightens its muscles to become rigid and tumbles down the hill to safety. Because it's so light, bouncing along the cliff face doesn't harm the little toad, and it can land uninjured in puddles or crevices. The strategy provides a quick escape from predators, like tarantulas, and makes up for its lack of jumping ability. 12 of 15 Surinam Toad Kevin Schafer / Getty Images The Surinam toad (Pipa pipa) is a Southern American species distinguished by its large size, flat back, and small eyes. It also has no tongue, and cannot croak. Instead, it taps two bones in its throat to make a high-pitched, sharp click noise. Its reproductive habits are perhaps its strangest feature. The toads mate underwater, and the female releases batches of three to 10 eggs at a time, which the male ushers onto her back. The eggs sink into the skin, forming pockets that hold the young through the tadpole stage. When her offspring finally emerge, it is as fully developed toads. 13 of 15 Purple Frog David V. Raju / Wikimedia Commons / CC BY-SA 4.0 The purple frog (Nasikabatrachus sahyadrensis) can be found only in the Western Ghats range in India, and is best known for its formless shape and underground lifestyle. In fact, it only emerges for two weeks during monsoon season to mate, and lives the rest of its life as a burrowing animal. While it's not the only frog that lives below ground, it is the only one that can feed itself without surfacing, relying solely on termites and ants it finds in the soil. Also known as the pignose frog due to its long snout, this species can thank 120 years of independent evolution for its unique characteristics. 14 of 15 Malagasy Rainbow Frog Linda D Lester / Getty Images The impressive Malagasy rainbow frog (Scaphiophryne gottlebei) from Madagascar goes by many unofficial names, including the ornate hopper and the red rain frog. Perhaps this is because just one name can't describe its coloration accurately, which varies from white to red to green, with black stripes in between. The species was listed as critically endangered from 2004-2008, until researchers discovered it was more abundant than once thought. It remains an endangered species due to shrinking habitat and high demand in the pet trade, though its export has been illegal since 2014. 15 of 15 Malayan Horned Frog The fleshy horns are all part of this species' camouflage strategy to look more like a leaf. Ryan M. Bolton / Shutterstock The Malayan horned frog or long-nosed horned frog (Megophrys nasuta) is a ground-dwelling frog that lives in the rainforests of Southeast Asia. It has an angular, mottled brown body, complete with a triangular nose and prominent horns over the eyes, that helps it hide in the leaf litter where it finds prey. This large species can grow to over five inches in length, and is a prodigious croaking talent with a loud "honking" call.