The Green Iguana or Common Iguana (Iguana iguana) is a large, arboreal herbivorous species of lizard of the genus Iguana native to Central, South America, and the Caribbean. The green iguana ranges over a large geographic area, from southern Brazil and Paraguay as far north as Mexico and the Caribbean Islands especially in Puerto Rico where they are also known as "Gallina de palo" and they are very common throughout the island and often eaten; and in the United States as feral populations in South Florida (including the Florida Keys), Hawaii, and the Rio Grande Valley of Texas.

A herbivore, it has adapted significantly with regard to locomotion and osmoregulation as a result of its diet. It grows to 1.5 metres (4.9 ft) in length from head to tail, although a few specimens have grown more than 2 metres (6.6 ft) with bodyweights upward of 20 pounds (9.1 kg).