The animal which eat only meat are called carnivores. e.g lion, tiger, hyena, wolf etc.
A carnivore is an animal or plant that eats the flesh of animals. Most, but not all, carnivorous animals are members of the Carnivora order; but, not all members of the Carnivora order are carnivorous.
"A carnivore is simply any species that eats meat, and this can range from carnivorous plants and insects to what we typically think of when we hear the word carnivore, like tigers or wolves," said Kyle McCarthy, an assistant professor of wildlife ecology in the University of Delaware's College of Agriculture and Natural Resources.
Carnivora — or "flesh devourers," in Latin — is an order of placental mammals that includes canids such as wolves and dogs, felids (cats), ursids (bears), mustelids (weasels), procyonids (raccoons), pinnipeds (seals) and others, according to Encyclopedia Britannica. The order consists of 12 families and 270 species in all.
While some carnivores eat only meat, other carnivores also supplement their diets with vegetation on occasion. For example, most bears are omnivores, which means they eat both plants and meat, McCarthy explained.
Carnivorous plants
Animals aren't the only carnivores — there are more than 600 species of carnivorous plants, according to the Botanical Society of America. These plants get at least some of their nutrients by trapping and digesting insects and sometimes even small frogs and mammals. Because the most common prey for most carnivorous plants are insects, these leafy flesh-eaters are also called insectivorous plants.
While most plants absorb nitrogen from the soil through their roots, carnivorous plants get nitrogen from animal prey that gets trapped in their modified leaves. The traps work in various ways. A Venus flytrap (Dionea muscipula), for example, has hinged leaves that snap shut when trigger hairs are touched. A pitcher plant has a pitfall trap; its leaves fold into deep pits filled with digestive enzymes. And sundews and butterworts have sticky mucus on their stalks that stops insects in their tracks.
Carnivore types
There are three different categories of carnivores based on the level of meat consumption: hypercarnivores, mesocarnivores and hypocarnivores.
Carnivores that eat mostly meat are called hypercarnivores. These creatures are considered obligate carnivores because they cannot properly digest vegetation and have a diet that consists of at least 70 percent meat, according to National Geographic. The cat family, including lions, tigers and small cats, for example, are obligate carnivores, as are snakes, lizards and most amphibians.
Many hypercarnivores, including some members of the Carnivora order, have heavy skulls with strong facial musculature to aid in holding prey, cutting flesh or grinding bones. Many also have a special fourth upper molar and first lower molar. "They close together in a shearing action, like scissors, which allows [the] animals to slice meat from their prey," said McCarthy. These two teeth together are called the carnassial teeth.