Rhinoceroses, often abbreviated to rhinos, are one of any five extant species of odd-toed ungulates in the family Rhinocerotidae, as well as any of the numerous extinct species. Two of these extant species are native to Africa and three to Southern Asia.
Members of the rhinoceros family are characterized by their large size (they are some of the largest remaining megafauna, with all of the species able to reach one tonne or more in weight); as well as by an herbivorous diet; a thick protective skin, 1.5–5 cm thick, formed from layers of collagen positioned in a lattice structure; relatively small brains for this size (400–600 g); and a large horn. They generally eat leafy material, although their ability to ferment food in their hindgut allows them to subsist on more fibrous plant matter, if necessary. Unlike other perissodactyls, the two African species of rhinoceros lack teeth at the front of their mouths, relying instead on their lips to pluck food.
Rhinoceros are hunted by humans for their horns, which are bought and sold on the black market, and which are used by some cultures for ornamental or traditional medicinal purposes. East Asia, specifically Vietnam, is the largest market for rhino horns. By weight, rhino horns cost as much as gold on the black market. People grind up the horns and then consume them believing the dust has therapeutic properties. The horns are made of keratin, the same type of protein that makes up hair and fingernails. Both African species and the Sumatran rhinoceros have two horns, while the Indian and Javan rhinoceros have a single horn.
The IUCN Red List identifies three of the species as critically endangered.
Several species of rhinoceros appeared in several episodes. The Snack Machine may have rhinoceros food in one of its slots (usually in the 7th and rightmost one)
The first appearance of a rhino in the series was in the episode "Slimy Buddies". The Snack Machine was shown to have rhino food in the last slot after Chris got mangos for Zoboomafoo from it. A black rhinoceros that was eating appeared as the last among several animals that were shown using slime to eat their food. Chris said that rhinos eat big food, so they need big slime.
White rhinos also appeared in "Running" when the Kratt brothers took a trip to the African grasslands to run with the animals and find out the way different animals run while doing so. When Martin said that "some animals just kind of lumber along like..." then wondered what animal moves that way, Chris stated the answer when a male white rhino appeared and states that he was headed towards them. Martin said that a rhino is a horned creature that looks kinda like a dinosaur. Chris adds that rhino can get as heavy as the truck he and Martin were on, but that he's peaceful and nice and that he usually just walks around the plains (a pair of black rhinos were shown when he said the last part). Martin then says that when a rhino wants to run, he can gallop as fast as a horse (a pair of white rhinos were shown galloping when he said that). When Chris asked the viewers if they want to run as fast as a rhino (another white rhino pair were shown running at a slower pace), he tells them to put their head down and run, which he does. A third pair of white rhinos were then shown trotting as they munched on plants, followed by Chris running like a rhino, then another white rhino trotting by a riverside, Martin running like a rhino, 3 more white rhinos rushing back towards the dry brush, and finally the Kratts stop and bump into each other. 1 more white rhino was shown drinking at the waterhole alongside the other animals and the Kratt brothers. The first white rhino also appeared during the Animal Friends song.
Rhinos were mentioned in "Giants". They were the 3rd of 5 African giant creatures mentioned by the Kratt brothers when they arrived at Animal Junction after a giant hike in Africa along with elephants, hippos, lions, and giraffes. The Snack Machine had rhinoceros food in the rightmost slot (next to walrus). When Zoboo was looking for the button for capybara food, this was the first button he found before finding the ones for walrus, then mouse, and finally capybara.
The Snack Machine once again had rhino food in "Who's Inside the Egg?". When Chris went to get cucumbers for Zoboomafoo to eat, it was in the last slot after chick and bear food; but when Zoboo went to get chick food for the chicks, it was in the first slot before bear and chick food (the opposite order) and the first slot he checked.
Another herd of white rhinos appeared in "Don't Fence Me In". When Chris and Martin didn't hear the pride of lions anymore, they think that the coast is clear and prepare to leave the inside of their tent, but when they peaked out from it, they saw a rhino bellow as it walked towards them, causing them to notice the rhino herd forcing them to retreat back inside. From there, Chris states that he was starting to feel a little fenced in. Martin agrees, stating that they were on the African savanna and they can't even leave their tent.
A white rhinoceros rolling in the mud was among the animals shown using mud in "Crocodilian".
A black rhinoceros with 2 oxpeckers on its back appeared in "World of Legs".
The latest episode to show rhinoceroses was the final episode of the series: "Messy and Clean" when the Kratt brothers were having snack time in Africa while checking out messy and clean creature behaviors. A pair of white rhinos (1 of which was a female) were shown rolling in the mud when Martin said that some animals get clean by first getting messier. He then described that it may look like the female rhino is getting messy on purpose, because she is: mud actually helps her keep cool and stops insects from biting her. Another white rhinoceros was shown along with getting cleaned by red-billed oxpeckers along with several African buffalo (called water buffalo) and a greater kudu