The Argentine Black and White Tegu (Salvator merianae) is a species of lizard in the family Teiidae. The species is the largest of the "tegu lizards". It is an omnivorous species which inhabits the tropical rain forests, savannas and semi-deserts of eastern and central South America. Juvenile tegus in the wild have been observed to eat a wide range of invertebrates including insects, annelids, crustaceans, spiders and snails. They also eat fruits and seeds. As they grow, they become more predatory and the protein content of their diet rises. They may seek out eggs from other reptiles' and from birds' nests and will eat small birds and other vertebrates such as fish, anurans, other lizards, snakes and small mammals, such as rodents.
Tegus are sometimes kept as pets by humans. They are notable for their unusually high intelligence and can also be housebroken. Like other reptiles, tegus go into brumation in autumn when the temperature drops. They exhibit a high level of activity during their wakeful period of the year.
Tegus are capable of running at high speeds and can run bipedally for short distances. They often use this method in territorial defense, with the mouth open and front legs held wide to look more threatening.