Iguana is a genus of lizard native to tropical areas of Central and South America and the Caribbean first described by Austrian naturalist Josephus Nicolaus Laurenti in his book Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena in 1768. The genus iguana includes two species: the Green Iguana (a popular pet) and the Lesser Antillean Iguana. The word "Iguana" is derived from a Spanish form of the original Taino name for the species "Iwana".

The two species of lizard within the genus Iguana possess a dewlap, a row of spines running down their back to their tail, and a third eye on their head. This eye is known as the Parietal eye, which looks just like a pale scale on the top of their head. Behind their neck are small scales which resemble spikes, known as tuberculate scales. They also have a large round scale on their cheek known as a subtympanic shield. Iguanas have excellent vision and are able to see shapes, shadows, color and movement at long distances. Iguanas use their eyes to navigate through crowded forests, as well as for finding food. They also use visual signals to communicate with members of the same species.

Galapagos land iguanas are territorial and signal their aggression with head-nodding. The male aggressively courts the female. Following copulation, the female flees and finds a spot to dig a nest in which to bury a clutch of up to 25 eggs. When Charles Darwin visited the Galapagos Islands in 1835, he found so many Galapagos land iguana burrows that he had to tread cautiously.