An omnivore is any animal that is a generalist feeder, consuming a wide variety of foods that can include both animal and plant matter. Because they have attributes of both carnivores and herbivores, omnivores have relatively diverse linkages within ecological food webs.
Some examples of omnivorous animals are pig and bear, both of which will eat a remarkably wide range of plant and animal products. Most wild populations of these animals are primarily herbivorous, eating a wide variety of plant products, depending on their seasonal and geographic availability. However, both of these animals are also opportunistic meat eaters. If meat can be readily attained through predation or scavenging, these animals will eagerly avail themselves of this food.
Interestingly, humans are the most omnivorous of all animals. Only a limited number of plant and animals species, about 100, are actually consumed by humans in relatively large quantities. However, products of additional thousands of plant and animal species are consumed as victuals by humans, as long as the food is nutritious and there is access to the resource. In a few cases, humans even consume some foods that are potentially extremely poisonous, usually for cultural reasons, or because in small amounts the toxin may act as a hallucinogen. One extreme case is the consumption by Japanese (especially men) of flesh of a puffer fish known as fugu (Spheroides rubripes) in sushi restaurants. This meal is prepared with exquisite care by highly skilled chefs, who must excise a small gland containing an extremely toxic biochemical called saxitoxin. If this preparation is not accomplished properly, then the meal will be quickly lethal to the patron. Because of this danger, the eating of fugu is considered to be an act of great bravado, for which the consumer gains respect in the eyes of his peers. This deliberate exposure to such an extraordinarily toxic food is symptomatic of the remarkable omnivory displayed by humans.