A carnivore is an animal that gets food from killing and eating other animals.
Carnivores generally eat herbivores, but can eat omnivores, and occasionally other carnivores. Animals that eat other animals, like carnivores and omnivores are important to any ecosystem, because they keep other species from getting overpopulated.
Since carnivores have to hunt down and kill other animals they require a large amount of calories. This means that they have to eat many other animals over the course of the year. The bigger the carnivore, the more it has to eat. You should make sure that you have many more herbivores and omnivores than carnivores.