Emerald Tree Boa The Emerald Tree Boa, also known as corallus caninus, is a non-venomous but aggressive breed of boas native to northern South America. They are great hunters, with a prehensile tail and large heat sensor. They grow around 4 to 6 feet and are known for their brilliant green scales, which hide them from prey and predators like birds and rodents. Baby boas are born in various colors but typically turn green by a year old.